JP4994084B2 - Ink-jet ink for color filter, color filter, method for producing the same, and display device - Google Patents

Abstract

The invention provides an ink jet fluid for color filter which is supplied to a concave part formed on a substrate surrounded and formed by adopting pixel of the color filter through the ink jetting method. The invention is characterized in that: the ink jet fluid for color filter at least contains a coloring pigment and an organic solvent, as an alkylene diol alkyl ether with boiling point above 250 deg C. as a organic solvent. The invention further provides a color filter using the ink fluid, its producing method and a display unit using the color filter.

Description

  The present invention relates to an inkjet ink for a color filter, a color filter, a method for producing the same, and a display device including the 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 color liquid crystal displays are expensive, there is an increasing demand for cost reduction. In particular, there is a high demand for cost reduction for color filters with high specific gravity.

  Such a color filter usually includes a coloring pattern of three primary colors of red (R), green (G), and blue (B). In a liquid crystal display provided with this color filter, the liquid crystal operates as a shutter by turning on and off the electrodes corresponding to the R, G, and B pixels, and the R, G, and B pixels are illuminated with light. Passes and color display is performed.

  As a conventional method for producing a color filter, 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) 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 part 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 itself is convex. There is a problem that the pixel becomes flat or concave and the flatness of the pixel cannot be obtained. 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 of obtaining a flatness of a pixel by providing a flattening layer on the pixel. In the above document, a method of exposing from the substrate side, adjusting the degree of curing of the planarization layer according to the thickness of the pixel, and imparting flatness is described, but regarding the variation in color density within the pixel, Nothing has been resolved. Further, Patent Document 3 discloses a method of forming a film-like protective layer by transfer, but similarly, variations in color density in pixels are not eliminated.

  Patent Document 4 discloses an ink having a color pigment and an extender pigment as an ink that imparts flatness of a pixel. In the above-mentioned document, the weight ratio between the resin and the pigment, the weight 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 a pixel 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 pixel flatness 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.

  Patent Documents 9 and 10 disclose a color filter having a pixel end having a thickness of 80% or more of the highest part, 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. In the above method, it is possible to prevent color mixing of the pixels and at the same time, it can be expected that the flatness of the pixel portion is improved, but the process becomes complicated and is not suitable for actual manufacturing.
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

  The present invention has been made in view of the above-described conventional problems. Ink-jet ink for a color filter capable of suppressing variation in pixel shape and suppressing swelling of partition walls, a color filter using this ink, and a method for manufacturing the same It is another object of the present invention to provide a display device using the color filter.

That is, the present invention
<1> An ink-jet ink for a color filter, which is applied by an ink-jet method to a recess surrounded by a partition formed on a substrate and is used for forming a pixel of a color filter, and contains at least a color pigment and an organic solvent And a compound having a boiling point of 250 ° C. or more selected from the group consisting of tripropylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether and triethylene glycol monoalkyl ether as one kind of the organic solvent. see containing and an organic solvent having a boiling point of not lower than 230 ° C. at atmospheric pressure, a non-aqueous inkjet ink for color filter which occupies more than 80% by weight of the total organic solvent.

<2> solubility in water at 25 ° C. of the boiling point of 250 ° C. or more compounds is an ink jet ink for a color filter according to Ru der below 10 g <1>.

<3> the boiling point of the ink-jet ink for a color filter according to the compounds of the above 250 ° C. is Ru tripropylene glycol monoalkyl ether der <1> or <2>.

<4> The color according to any one of <1> to <3>, wherein the compound having a boiling point of 250 ° C. or higher includes at least one of tripropylene glycol mono n-butyl ether and tripropylene glycol mono n-propyl ether. Inkjet ink for filters.
<5> The inkjet ink for color filter according to any one of the polymerizable groups further you containing monomer having at least two <1> to <4>.

<6> The polymerizable group is an ink jet ink for a color filter according to the epoxy groups, Ru der one selected from the group consisting of acryloyloxy group and methacryloyloxy group <5>.

<7> The inkjet ink for a color filter according to the compound having a polymerizable group three or more <5> or <6> accounting for more than 50% by weight of the monomer.

<8> The inkjet ink for color filter according to any one of the further you containing a binder resin <1> to <7>.

<9> The inkjet ink for color filter according to any one of you further contains a surfactant <1> to <8>.

<10> a viscosity at 25 ° C. is a color inkjet ink filter according to any one of Ru Der below 5 mPa · s or more 30 mPa · s <1> to <9>.

<11> A pixel is formed by applying a droplet of the inkjet ink for a color filter according to any one of <1> to <10> to a recess surrounded by a partition formed on a substrate by an inkjet method. it is to Luke error method of manufacturing a filter.

<12> After removing the organic solvent contained in the droplets to form an ink residue, the ink residue is polymerized by irradiating the ink residue with active energy rays and / or heating the ink residue. that form a pixel <11> is a method for producing a color filter according to.

<13><11> or a color filter manufactured by the method for producing a color filter according to <12>.

<14> a Viewing device Ru comprising the color filter according to <13>.

  According to the present invention, there are provided an inkjet ink for a color filter capable of suppressing variation in pixel shape and suppressing swelling of a partition wall, a color filter using the ink, a manufacturing method thereof, and a display device using the color filter. Is done.

  Hereinafter, the inkjet ink for color filter, the color filter, the manufacturing method thereof, and the display device of the present invention will be described in detail.

<Inkjet ink for color filter>
The inkjet ink for color filter of the present invention (hereinafter sometimes referred to as “the ink of the present invention”) is surrounded by a partition wall (hereinafter sometimes referred to as a black matrix or BM) formed on a substrate. An ink which is applied to the concave portion by an ink jet method and is used for forming a pixel of a color filter, which contains at least a coloring pigment and an organic solvent, and tripropylene glycol monoalkyl ether and dipropylene as one kind of the organic solvent A compound having a boiling point of 250 ° C. or higher selected from the group consisting of glycol monoalkyl ether, tetraethylene glycol monoalkyl ether and triethylene glycol monoalkyl ether (hereinafter referred to as “an alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher”). " Department.) Is characterized in that comprises a.
The ink of the present invention may contain a pigment dispersant, a monomer, a binder resin, a polymerization initiator, a surfactant, or other additives as necessary.

  According to the ink of the present invention, it is possible to suppress drying of the ink after the ink is applied to the concave portion surrounded by the partition formed on the substrate, and the deterioration of the flatness of the pixel due to drying unevenness can be suppressed. Can be prevented. As a result, it is possible to suppress variations in pixel shape. Furthermore, by using an alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher as a kind of solvent, swelling of the partition walls can be suppressed.

  The viscosity at 25 ° C. of the inkjet ink for a color filter of the present invention is preferably 5 mPa · s or more and 30 mPa · s or less, and more preferably 7 mPa · s or more and 25 mPa · s or less from the viewpoint of securing the dischargeability from the inkjet head. preferable.

Next, each component contained in the ink of the present invention will be described in detail.
(Coloring agent)
As the colorant used in the ink of the present invention, known pigments such as organic pigments, inorganic pigments, and dyes can be used, but sufficient transmission density, light resistance, adhesion to the substrate, and other various resistances are required. Therefore, various organic pigments are suitable. Specific examples of the colorant include pigments and dyes described in JP-A-2005-17716 [0038] to [0054], pigments described in JP-A-2004-361447 [0068] to [0072] The colorants described in JP-A-2005-17521 [0080] to [0088] can be preferably used. Among these, pigments are particularly preferable from the viewpoint of storage stability of pixels.
The content of the colorant in the present invention is not particularly limited, but from the viewpoint of obtaining a desired hue and density, the proportion of the colorant in the remainder of the ink is preferably 20% by mass or more, and 20 to 70% by mass. Is more preferable, 25-60 mass% is more preferable, and 30-50 mass% is especially preferable.

In the present invention, the combination of the above-described pigments preferably used in combination is 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 or C.I. I. A combination with Pigment Violet 23 is mentioned. 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. C. I. In Pigment Blue 15: 6, C.I. I. Pigment violet 23 or C.I. I. A combination with Pigment Blue 60 is mentioned.
C. in the pigment when used together in this way. I. Pigment red 254, C.I. I. Pigment green 36, C.I. I. The content of Pigment Blue 15: 6 is C.I. I. Pigment Red 254 is preferably 60% by mass or more, particularly preferably 70% by mass or more. C. I. The pigment green 36 is preferably 50% by mass or more, particularly preferably 60% by mass or more. C. I. Pigment Blue 15: 6 is preferably 80% by mass or more, and particularly preferably 90% by mass or more.

  The pigment used in the present invention preferably has a number average particle size of 0.001 to 0.1 μm, more preferably 0.01 to 0.08 μm. When the number average particle diameter of the pigment is 0.001 μm or more, it is preferable because the surface energy of the particles is small and aggregation is difficult, the dispersion of the pigment is facilitated, and the dispersion state is easily kept stable. Further, if the number average particle diameter of the pigment is 0.1 μm or less, it is preferable because the polarization is not canceled by the pigment and the contrast is improved. The “particle diameter” as used herein refers to the diameter when the electron micrograph image of the particle is a circle of the same area, and the “number average particle diameter” is the above-mentioned particle diameter for a number of particles, The average value of 100 is said.

  The pigment is desirably used as a dispersion. This dispersion can be prepared by dispersing a composition obtained by previously mixing the pigment, a pigment dispersant described later, and an organic solvent using a known disperser. 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 the composition obtained by mixing the pigment and the pigment dispersant in advance by adding to a monomer described later and dispersing it. 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.

(Pigment dispersant)
In order to obtain pigment dispersion stability, it is preferable to add a pigment dispersant to the ink of the present invention.
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.
Examples of the pigment 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, Polymer 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 nonyl Phenyl ether, stearylamine acetate, pigment derivatives and the like can be used.

  As specific examples of the pigment dispersant, the examples described in paragraphs [0021] to [0023] of JP-A-2005-15672 can be used as preferred examples of the present invention.

  Other pigment dispersants used in the present invention include “a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and does not contain a polyether chain. Pigment dispersant ".

  As the main chain structure having a constitutional unit based on diisocyanate and / or triisocyanate monomer, the molecular structure in which isocyanate groups are bonded to each other between the diisocyanate and / or triisocyanate molecules. Is mentioned. Further, the chain structure of the main chain skeleton may contain a ring structure such as an aromatic ring and / or a heterocyclic ring which may have a substituent.

  Examples of the main chain structure in which diisocyanates and / or triisocyanates are polymerized include polyisocyanates represented by the formulas (A-1) to (A-5), and these polyisocyanates further undergo a polymerization chain. And may further have a substituent. 2-Methacryloylethyl isocyanate is commercially available, for example, under a trade name such as “Karenz MOI” manufactured by Showa Denko K.K.

  Formula (A-1) is a trade name such as “Death Module IL” manufactured by Bayer, and Formula (A-2) is a trade name such as “Death Module HL” manufactured by Bayer, for example. A-3) is a trade name such as “Pollen KC” manufactured by Esseapiichi Co., Ltd., Formula (A-4) is a trade name such as “Pollen HR” manufactured by Esseapiichi Co., Ltd., and Formula (A-5) is, for example, manufactured by Esseapiichi Corporation. It is commercially available as “toluene diisocyanate-isophorone diisocyanate-isocyanurate”.

  Diisocyanates used in “pigment dispersants comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and not containing polyether chains” Aromatic isocyanates are preferable in terms of their properties, for example, benzene diisocyanates such as benzene-1,3-diisocyanate and benzene-1,4-diisocyanate; toluene-2,4-diisocyanate, toluene-2,5-diisocyanate, Toluene diisocyanates such as toluene-2,6-diisocyanate, toluene-3,5-diisocyanate; 1,2-xylene-3,5-diisocyanate, 1,2-xylene-3,6-diisocyanate, 1,2-xylene -4,6-diisocyanate, 1,3 Xylene-2,4-diisocyanate, 1,3-xylene-2,5-diisocyanate, 1,3-xylene-2,6-diisocyanate, 1,3-xylene-4,6-diisocyanate, 1,4-xylene- Aromatic diisocyanates such as xylene diisocyanates such as 2,5-diisocyanate and 1,4-xylene-2,6-diisocyanate can be mentioned. Examples of the triisocyanates include benzene-1,2, Benzene triisocyanates such as 4-triisocyanate, benzene-1,2,5-triisocyanate, benzene-1,3,5-triisocyanate; toluene-2,3,5-triisocyanate, toluene-2,3 6-triisocyanate, toluene-2,4,5-triisocyanate, Torentic isocyanates such as ene-2,4,6-triisocyanate, toluene-3,4,6-triisocyanate, toluene-3,5,6-triisocyanate; 1,2-xylene-3,4,6 -Triisocyanate, 1,2-xylene-3,5,6-triisocyanate, 1,3-xylene-2,4,5-triisocyanate, 1,3-xylene-2,4,6-triisocyanate, Xylene triisocyanates such as 1,3-xylene-3,4,5-triisocyanate, 1,4-xylene-2,3,5-triisocyanate, 1,4-xylene-2,3,6-triisocyanate, etc. And aromatic triisocyanates. Of these, toluene diisocyanates are preferred from the viewpoint of high heat resistance. These diisocyanates and triisocyanates can be used alone or in admixture of two or more. In particular, a main chain structure in which toluene diisocyanates as represented by formula (A-1) or formula (A-4) are polymerized alone is preferable from the viewpoint of high heat resistance.

“A pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and not including a polyether chain” is a polyether from the viewpoint of heat resistance. It is a polymer containing no chain. Here, the polyether chain refers to a structure represented by — (O—R ⁱ ) n— (R ⁱ is an alkylene group having 1 to 10 carbon atoms, and n is an integer of 2 or more). _{Specifically, - (O-CH 2 CH} 2) n -, - (O-CH 2 CH 2 CH 2) n -, - (O-CH 2 CH 2 CH 2 CH 2) n -, - (O _{-CH 2 CH 2 CH 2 CH 2} CH 2) n -, - (O-CH 2 CH 2 CH 2 CH 2 CH 2 CH 2) n- can be mentioned.

  From the viewpoint of the stability of the ink of the present invention, “a pigment dispersion comprising a polymer having a main chain structure obtained by polymerizing at least diisocyanates and / or triisocyanates as monomer units and not containing a polyether chain”. The “agent” preferably has no acidic functional group. When the pigment dispersant contains an acidic functional group, the acidic functional group of the pigment dispersant acts as a curing agent, and thus it may be difficult to adjust the stability. Examples of the acidic functional group include a carboxyl group, a sulfonic acid group, and a phosphoric acid group, and a typical example is a carboxyl group.

In the case where the “pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and not including a polyether chain” includes a polyester chain. Is preferable because the dispersibility of the pigment is improved by this polyester chain. Here, the polyester ^{chain, - (O-R j CO} ) n- (R j represents an alkylene group having 1 to 20 carbon atoms, n represents an integer of 2 or more) refers to a structure represented by. Specific examples include polylactones such as polycaprolactone, polyvalerolactone, and polypropiolactone, and polycondensation polyesters such as polyethylene terephthalate and polybutylene terephthalate. Among these, from the viewpoint of heat resistance, it is preferable to include polylactones and further polycaprolactone. The polyester chain is preferably introduced by reacting with an isocyanate group of the above isocyanates using a polyester having a hydroxyl group at one or both ends.

  In addition, from the viewpoint of pigment dispersibility, “a pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and does not contain a polyether chain” The amine value of is preferably 5 to 80 mg KOH / g. The amine value is an amine value per gram of solid content, and is a value converted to an equivalent of potassium hydroxide after being obtained by potentiometric titration using a 0.1N hydrochloric acid aqueous solution.

  In addition, the oxidation of the “pigment dispersant composed of 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” is stored in the ink. A lower value is preferable from the viewpoint of stability, and a value that can be regarded as having substantially no acidic functional group, specifically, an acid value of 10 mgKOH / g or less is preferable, and 3 mgKOH / g or less is particularly preferable. In addition, an acid value shows the acid value per 1g of solid content, and says the value calculated | required by the potentiometric titration method according to JISK0070.

  Furthermore, the molecular weight of the “pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and not including a polyether chain” is in terms of polystyrene. A weight average molecular weight in the range of 500 to 30,000 is preferred. When the molecular weight of the dispersant is less than 500, the dispersion stability is lowered, and when it exceeds 30,000, the inkjet dischargeability tends to be lowered. In addition, a weight average molecular weight (Mw) means the value calculated | required by the gel permeation chromatography (GPC) (For example, HLC-8029, Tosoh Corporation make) which used tetrahydrofuran containing 20 mmol / l of citric acid as a developing solution.

  Disperbyk-161 is a commercially available product of “a pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and does not contain a polyether chain”. 162 (above, manufactured by Big Chemie Japan Co., Ltd.).

  "A pigment dispersant comprising a polymer having a main chain structure in which at least diisocyanates and / or triisocyanates are polymerized as monomer units and not including a polyether chain" may be used alone or in combination of two or more. Can be used as a mixture.

  When a polymer having a main chain structure obtained by polymerizing at least diisocyanates and / or triisocyanates as a monomer unit and not containing a polyether chain is used as a pigment dispersant, a pigment is contained in the pigment dispersion. The pigment dispersant is usually used in an amount of 10 to 200 parts by weight, preferably 20 to 80 parts by weight per 100 parts by weight. Even when contained in such a relatively small proportion, the dispersibility can be sufficiently improved, so that a pigment dispersion and an inkjet ink with a small amount of pigment dispersant can be obtained, and the pigment dispersant for the heat resistance of the coating film. The influence of can be reduced.

(Organic solvent)
In the ink of the present invention, an alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher is used as a kind of organic solvent. The solubility of the alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher in water at 25 ° C. is preferably 10 g or less, and more preferably 5 g or less. When the solubility in water at 25 ° C. is 10 g or less, swelling of the partition walls can be suppressed. Also, good dispersion stability of the pigment can be obtained.

  Examples of the alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher include tripropylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether, triethylene glycol monoalkyl ether, and the like. Among these, tripropylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether and the like are preferable, and tripropylene glycol n-butyl ether and tripropylene glycol n-propyl ether which are a kind of tripropylene glycol monoalkyl ether are more preferable. It is done.

  The amount of alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or more in the total organic solvent contained in the ink of the present invention is preferably 30% by mass or more, more preferably 40% by mass or more, and particularly preferably 50% by mass or more. . If the amount of alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher is 30% by mass or more, the variation in the shape of pixels in the plane can be improved.

  The ink of the present invention may contain an organic solvent other than alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher as necessary. Specific examples of other organic solvents include, for example, dipropylene glycol monomethyl ether, propylene glycol diacetate, dipropylene glycol monomethyl ether acetate, propylene glycol-n-butyl ether acetate, dipropylene glycol mono-n-butyl ether, tripropylene glycol Methyl ether acetate, diethylene glycol monobutyl ether, 1,3-butanediol diacetate, dipropylene glycol-n-propyl ether acetate, propylene carbonate, diethylene glycol monobutyl ether acetate, dipropylene glycol-n-butyl ether acetate, ethylene glycol monobutyl ether acetate, Diethylene glycol monoethyl ether Seteto, diethylene glycol dibutyl ether, diethyl adipate, dibutyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, and may be mentioned diethyl succinate.

  The ink of the present invention only needs to contain an alkylene glycol monoalkyl ether having a boiling point of 250 ° C. or higher as a kind of organic solvent, but a solvent having a boiling point of 230 ° C. or higher at normal pressure is included in the ink of the present invention. The organic solvent preferably accounts for 80% by mass or more, more preferably 85% by mass or more, and particularly preferably 90% by mass or more. When the solvent having a boiling point of 230 ° C. or higher at normal pressure occupies 80% by mass or more of the total organic solvent contained in the ink of the present invention, it is possible to suppress the drying of the ink on the inkjet head, and the ink is discharged by drying the ink. Defects can be improved.

Further, the ink of the present invention may contain an alkane solvent as a kind of organic 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-based 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.

(monomer)
The monomer having two or more polymerizable groups used in the ink of the present invention (hereinafter sometimes referred to as a bifunctional or higher monomer) is particularly limited as long as it can be polymerized by active energy rays and / or heat. Although not intended, a monomer having three or more polymerizable groups (hereinafter sometimes abbreviated as a tri- or higher functional monomer) is more preferable from the viewpoint of film strength and solvent resistance. The proportion of the tri- or higher functional monomer in the whole monomer is preferably 50% by mass or more, and more preferably 70% by mass or more.

The type of the polymerizable group is not particularly limited, but the viscosity of the polymerizable monomer itself is increased by increasing the number of functional groups. Therefore, it is preferable that the viscosity of the functional group itself is low, such as an acryloyloxy group, a methacryloyloxy group, Particularly preferred is any one selected from the group consisting of epoxy groups.
Specific examples of the tri- or higher functional polymerizable monomer include a trifunctional epoxy group-containing monomer described in paragraph Nos. 0061 to 0063 of JP-A No. 2001-350012 and paragraph No. 0016 of JP-A No. 2002-371216. And trifunctional or higher acrylate monomers, methacrylate monomers, and trifunctional or higher functional monomers described in “Market Prospects of Reactive Monomers” published by CMC Publishing Co., Ltd. Among these, trimethylolpropane triacrylate, trimethylolpropane PO (propylene oxide) modified triacrylate, trimethylolpropane EO (ethylene oxide) modified triacrylate, pentaerythritol tetraacrylate, trimethylolpropane triacrylate are particularly preferable. Examples include, but are not limited to, methacrylate, pentaerythritol triacrylate, glycerol polyglycidyl ether, diglycerol polyglycidyl ether, and trimethylolpropane polyglycidyl ether. It is also possible to use two or more of the above trifunctional monomers.

  Examples of the tetrafunctional or higher functional monomer or oligomer include pentaerythritol tetraacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, and the like. Among these, particularly preferred are dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate, but are not limited thereto.

  The epoxy group-containing monomer is not particularly limited as long as it contains two or more epoxy groups in one molecule. For example, 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 novolak type epoxy resin, trishydroxyphenylmethane type epoxy Resin, trifunctional epoxy resin, tetraphenylolethane type epoxy resin, dicyclopentadienephenol type epoxy resin, hydrogenated bisphenol A type epoxy resin, bisphenol A Nuclear polyol type epoxy resins, polypropylene glycol type epoxy resins, 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.

  For the purpose of reducing the viscosity of the remaining ink and promoting the polymerization reaction of the pixel portion, a monofunctional monomer or a bifunctional monomer may be used in combination as appropriate. 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.

  In addition, in order to supplement the strength of the film or to provide close contact with the substrate, a small amount of a high-viscosity monomer having a viscosity at 25 ° C. of 700 mPa · s or more, a highly polar monomer such as urethane acrylate, and a small amount of oligomer are used It doesn't matter. There is no restriction | limiting in particular as a polyfunctional monomer, a highly polar monomer, and an oligomer preferable when using together, 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 Toa Gosei 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 these combined monomers added can be adjusted as appropriate.

  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. Reticulation is less likely to occur, and solvent resistance when providing an alignment film is improved. 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.

(Binder resin)
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. However, 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) Photocurable binder resin In a photocurable resin (photocurable binder resin) that can be polymerized and cured by light such as ultraviolet rays and electron beams, film formability and adhesion to a coated surface are imparted. For the purpose, it is preferable to include a polymer having a relatively high molecular weight. Here, the relatively high molecular weight means that the molecular weight is higher than that of so-called monomers and oligomers, and the weight average molecular weight can be 5,000 or more. 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.

The polymer itself having polymerization reactivity is an oligomer obtained by introducing a polymerizable functional group into a non-polymerizable binder molecule or a polymer having a higher molecular weight than an oligomer, and is itself exposed to light irradiation. May cause a polymerization reaction, or may induce a polymerization reaction by the action of other components such as a photopolymerization initiator activated by light irradiation.
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 25,000 or less.
The polymer having a relatively high molecular weight can be usually blended at a ratio of 1 to 50% by weight 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 with 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.

（Ｒ¹は水素原子または炭素数１〜３のアルキル基であり、Ｒ²は炭素数１〜１２
の炭化水素基である。）

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

(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).

(R ¹ and R ² are the same as in 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, and 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).

(R ³ is the same as 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 main chain constituent units other than those of formula (1) or formula (2) as long as 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). The weight ratio with the monomer to be charged (monomer that derives formula (1): monomer that derives formula (2)) is in the range of 10:90 to 90:10. preferable.
When the amount of the structural unit of the formula (1) is more than the above ratio of 10:90, there is a possibility that the reaction point of curing decreases and the crosslinking density is lowered, whereas the structural unit of the formula (2) If the amount is more than the above ratio 90:10, the bulky skeleton may be reduced and curing shrinkage may be 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. This is because if the molecular weight of the binder epoxy compound is less than 3,000, physical properties such as strength and solvent resistance required for pixels as details of the color filter are likely to be insufficient. 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 more than 20,000, the viscosity is likely to increase, the stability of the ejection amount when ejected from the ejection head and the straightness in the ejection direction may be degraded, and the stability of long-term storage is degraded. Because there is a fear.

  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.

  As a synthesis example of the binder epoxy compound, for example, a solvent containing no hydroxyl group is charged into a four-necked flask equipped with a thermometer, a reflux condenser, a stirrer, and a dropping funnel, and the temperature is raised to 120 ° C. while stirring. . The reason for using a solvent that does not contain a hydroxyl group is to avoid the decomposition of the epoxy group during the synthesis reaction. Next, a mixture of the monomer represented by the above formula (3), the monomer represented by the above formula (4), and a composition obtained by combining other monomers as necessary with a polymerization initiator (dropping component) is 2 Drop at a constant rate from the dropping funnel over time. After completion of the dropping, the temperature is lowered to 120 ° C., a catalyst is added, the reaction is performed for 3 hours, and the reaction is terminated when the temperature is raised to 130 ° C. and kept for 2 hours, whereby the binder epoxy compound is obtained.

  In addition, the polystyrene conversion weight average molecular weight of an epoxy compound can be calculated | required by GPC (gel permeation chromatography), As a measurement condition, tetrahydrofuran is used as a developing solution, for example, HLC-8029 (made by Tosoh Corporation) is used. Can be measured.

  Since the epoxy group (glycidyl group) is introduced into the binder epoxy compound by the structural unit represented by the formula (2), there is a limit to the amount of epoxy that can be introduced into the molecule of the copolymer. When a polyfunctional epoxy compound having a relatively small molecular weight is used in combination, the reaction point concentration of the epoxy increases and the crosslinking density can be increased.

(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. As the polymerization initiator, a photopolymerization initiator is used when the pixel portion is polymerized by active energy rays, and a thermal polymerization initiator is used when the pixel portion is polymerized by heat. 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 a —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, methyl acetoacetate 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.

As content of a photoinitiator and / or a thermal-polymerization initiator, 0.5-20 mass% is preferable with respect to the quantity of a monomer, More preferably, it is 1-15 mass%. If the content of the polymerization initiator is 0.5% by mass or more with respect to the monomer, the effect as the polymerization initiator can be sufficiently exerted, and if it is 20% 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.

Further, the thermosetting binder resin is usually combined with a curing agent. As the curing agent, for example, a polyvalent carboxylic acid anhydride or a polyvalent carboxylic acid is used.
Specific examples of polycarboxylic anhydrides include phthalic anhydride, itaconic anhydride, succinic anhydride, citraconic anhydride, dodecenyl succinic anhydride, tricarbaric 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 bistrimellitate and glycerin tristrimitate 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.

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 weight part normally per 100 weight part of components (monomer and resin) containing an epoxy group, Preferably it is 5-50 weight part. When the blending amount of the curing agent is less than 1 part by weight, curing becomes insufficient and a tough coating film cannot be formed. Moreover, when the compounding quantity of a hardening | curing agent exceeds 100 weight part, while the adhesiveness with respect to the board | substrate of a coating film is inferior, a uniform and smooth coating film cannot be formed.
In the present invention, a catalyst capable of accelerating the thermosetting reaction between acid and epoxy may be added to the thermosetting binder resin in order to improve the hardness and heat resistance of the pixel. 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, phosphoric acid mono- 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.

(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 and manufacturing method thereof>
The color filter manufacturing method of the present invention is characterized in that a pixel is formed by applying a droplet of the ink of the present invention to a recess surrounded by a partition formed on a substrate by an ink jet method.

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.

-Pixel formation process-
In the pixel formation step, the ink droplets of the ink of the present invention are applied to the recesses between the partition walls (dark color separation walls) to form pixels. This pixel is a color pixel of red (R), green (G), blue (B), etc. constituting the color filter.
As described above, the inkjet ink for forming a pixel (for example, RGB three-color pixel pattern) is invaded into the recess surrounded by the partition formed on the substrate as described above, and two or more colors are formed. It can be formed of a plurality of pixels.
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 selection of usable organic 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%. Further, the drive frequency is preferably 1 to 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 organic solvent contained in the droplets to form an ink residue, the ink residue is irradiated with an active energy ray (hereinafter sometimes referred to as a first curing step) and / or. Alternatively, pixels 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 organic solvent to form an ink residue, pixels are formed by polymerizing the ink residue by a process of irradiating the ink residue with active energy rays and / or heating the ink residue at a temperature of T ° C. or higher. 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) in which at least one color pixel formed in the pixel forming step is cured by irradiation with active energy rays can be provided. In the first curing step, cured pixels can be formed by curing the ink of the present invention for each color including red (R), green (G), and blue (B). Curing may be performed every time one color pixel is formed, or may be performed after a plurality of color pixels are formed.

  Curing of the ink of the present invention such as R, G, and B can be performed by performing an exposure process that promotes polymerization and curing using an energy source that emits active energy rays in a wavelength region corresponding to the photosensitive wavelength of the ink.

  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 pixels having a desired hue including red (R), green (G), and blue (B) by heat is provided. be able to. 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 pixel and a partition wall having a desired hue are formed, and after the first curing step, a heat treatment (so-called baking treatment) can be performed to cure by heat. In other words, a substrate on which pixels and barrier ribs photopolymerized by light irradiation are formed can be heated by being put in an electric furnace, a dryer or the like, or can be heated by being irradiated with an infrared lamp.

  The heating temperature and heating time at this time depend on the composition of the inkjet ink and the thickness of the pixel, but are generally about 120 ° C. to about 250 ° C. from the viewpoint of ensuring sufficient solvent resistance, alkali resistance, and ultraviolet absorbance. Heating for about 10 minutes to about 120 minutes is preferred.

Further, in the method for producing a color filter using the ink of the present invention, a preheating step may be provided before performing pixel polymerization by exposure to active energy rays and / or heat treatment. The heating temperature in the preheating step is not particularly limited, but when the temperature at which the thermal polymerization of the pixel starts is T ° C., a temperature that is less than T ° C. and does not cause the polymerization of the pixel portion is preferably 50 ° C. or more and 100 More preferably, it is 60 ° C. or higher and 90 ° C. or lower. By including the above steps, the evaporation of the organic solvent in the ink applied by the ink jet method is promoted, the color filter can be efficiently produced, and the viscosity of the remaining ink is reduced by heat. High fluidity can be obtained, and a color filter having a highly flat pixel portion can be obtained.
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 the ink is heated, the polymerization of the ink starts by heating, and the gelation of the ink is observed. More specifically, T is the heating temperature when the increase in ink viscosity after heating is 5 mPa · s or more with respect to the ink viscosity before heating.

  In the method for producing a color filter using the ink of the present invention, the steps from the pixel formation step to the preliminary heating step, the first curing step, and the second curing step are preferably performed within 24 hours, and within 12 hours. More preferably, it is more preferably performed within 6 hours. By performing the process from pixel formation to the final curing step (second curing step) within 24 hours, aggregation of pigments in the ink and precipitation of various binders can be prevented, and the surface state of the pixel can be improved. Can do.

(Partition wall)
In the present invention, a pixel is formed by applying a droplet of the 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 property 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-A-2005-3861, black matrixes described in paragraph numbers [0012] to [0021] of JP-A-2004-240039, and JP-A 2006-17980 are disclosed. 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, see 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) Method of imparting ink repellency by plasma treatment (for example, see JP-A-2002-62420), (4) Method of applying an ink-repellent material to the upper surface of the partition wall (See, for example, Japanese Patent Application Laid-Open No. 10-123500). In particular, (3) a method of performing an ink repellent treatment with plasma on a partition formed on a substrate is preferable.

  After forming the color filter by forming the 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 is produced by the above-described method for producing the color filter of the present invention, and includes, for example, 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 system. It can be suitably applied to applications such as without particular limitation. 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 ink of the present invention.

<Display device>
The display device of the present invention is not particularly limited as long as it includes the color filter of the present invention described above, and a display device such as a liquid crystal display device, a plasma display display device, an EL display device, a CRT display device, etc. Is mentioned. 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 of the present invention, 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 device of the present invention includes ECB (Electrically Controlled Birefringence), TN (Twisted Nematic), IPS (In-Plane Switching), FLC (Ferroelectric Liquid Crystal), OCB (OpticBandNitRic). Various display modes such as (Vertical Aligned), HAN (Hybrid Aligned Nematic), and GH (Guest Host) can be adopted. The display device of the present invention is characterized by including the color filter as described above, so that there is no display unevenness when mounted on a television or a monitor, and a wide color reproduction range and a high contrast ratio can be obtained. The display device of the present invention can also be suitably used for large screen display devices such as personal computer displays and television monitors.

  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 dark color composition for barrier rib formation]
In the dark color composition K1, first, K pigment dispersion 1 and propylene glycol monomethyl ether acetate in the amounts shown in Table 1 are weighed, mixed at a temperature of 24 ° C. (± 2 ° C.), and stirred at 150 rpm for 10 minutes. While stirring, the amounts of methyl ethyl ketone, binder 2, hydroquinone monomethyl ether, DPHA solution, 2,4-bis (trichloromethyl) -6- [4 '-(N, N-bisdiethoxycarbonylmethyl) shown in Table 1 Amino-3′-bromophenyl] -s-triazine and surfactant 1 are weighed out and added in this order at a temperature of 25 ° C. (± 2 ° C.) and stirred at a temperature of 40 ° C. (± 2 ° C.) at 150 rpm for 30 minutes. It is obtained by doing. In addition, the quantity of Table 1 is a mass part, and has the following composition in detail.

<K pigment dispersion 1>,
・ Carbon black (Nippex 35 manufactured by Degussa) 13.1%
・ Dispersant (Compound 1 below) 0.65%
-Polymer (benzyl methacrylate / methacrylic acid = 72/28 molar ratio random copolymer, 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 500 ppm of polymerization inhibitor MEHQ, manufactured by 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%

(Formation of partition walls)
The alkali-free glass substrate was cleaned with a UV cleaning apparatus, then brush-cleaned with a cleaning agent, and further ultrasonically cleaned with ultrapure water. The substrate was heat-treated at 120 ° C. for 3 minutes to stabilize the surface state.
After cooling the substrate and adjusting the temperature to 23 ° C., a dark color prepared as described above with a glass substrate coater (manufactured by FS Asia Co., Ltd., trade name: MH-1600) having a slit-like nozzle. Composition K1 was applied. Subsequently, a part of the solvent was dried with a VCD (vacuum dryer, manufactured by Tokyo Ohka Kogyo Co., Ltd.) for 30 seconds to eliminate the fluidity of the coating layer. A composition layer K1 was obtained.
In a proximity type exposure machine (manufactured by Hitachi High-Tech Electronics Engineering Co., Ltd.) with an ultra-high pressure mercury lamp, the exposure mask surface and dark color composition with the substrate and mask (quartz exposure mask with image pattern) standing vertically The distance between the physical layers K1 was set to 200 μm, and pattern exposure was performed in a nitrogen atmosphere with an exposure amount of 300 mJ / cm ² to a partition wall width of 20 μm and a space width of 100 μm.

Next, pure water is sprayed with a shower nozzle to uniformly wet the surface of the dark color composition layer K1, and then a KOH developer (containing a nonionic surfactant, trade names: CDK-1, Fuji Film). Electronics Materials Co., Ltd. 100-fold diluted) 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 is sprayed at a pressure of 9.8 MPa with an ultrahigh pressure cleaning nozzle to remove the residue, and a dark color composition layer K1 of the substrate is formed at an exposure amount of 2500 mJ / cm ^{2 in} the atmosphere. The film was post-exposed from the surface side and heated in an oven at 240 ° C. for 50 minutes to obtain a stripe-shaped partition wall having an opening having a thickness of 2.0 μm, an optical density of 4.0, and a width of 100 μm.

[Ink repellent plasma treatment]
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.
Gas used: CF ₄
Gas flow rate: 80sccm
Pressure: 40Pa
RF power: 50W
Processing time: 30 sec

[Example 2]
-Preparation of pigment dispersion for Red-
As a diketopyrrolopyrrole pigment, C.I. I. Pigment Red 254 (trade name: Irgaphor Red B-CF, manufactured by Ciba Specialty Chemicals Co., Ltd.) and a dispersant (the above compound 1) and a solvent (1,3-butanediol diacetate) (hereinafter, 1,3-BGDA) Are blended as shown in Table 2 below, and after premixing, motor mill M-50 (manufactured by Eiger Japan Co., Ltd.) is used with zirconia beads having a diameter of 0.65 mm at a filling rate of 80%. Dispersion was carried out at a speed of 9 m / s for 25 hours to prepare a Red pigment dispersion (R1). In the Red pigment dispersion (R1), the Red pigment dispersion (R2), (Y1) was the same as the Red pigment dispersion (R1) except that the pigment and other components were blended as shown in Table 2. Was prepared. In addition, the number average particle diameter of this pigment dispersion was measured using Nikkiso Nanotrac UPA-EX150.

Details of the materials used are shown.
C. I. Pigment Red 254 (trade name: Irgaphor Red B-CF, manufactured by Ciba Specialty Chemicals Co., Ltd.)
C. I. Pigment Red 177 (trade name: Chromophthal Red A2B, manufactured by Ciba Specialty Chemicals Co., Ltd.)
C. I. Pigment Yellow 150 (trade name: Bayplast Yellow 5GN 01, manufactured by Bayer Corporation)

-Preparation of Red ink for color filter-
(Monomer solution)
A solvent, a monomer, a binder, and a surfactant component were mixed as in the following composition, and after stirring at 25 ° C. for 30 minutes, it was confirmed that there was no insoluble matter, and a monomer solution (R1) was prepared.

1,3-BGDA (1,3-butanediol diacetate;
Boiling point: 232 ° C, manufactured by Daicel Corp.) 4.6g
40.2 g of TPNB (tripropylene glycol n-butyl ether; boiling point 274 ° C.)
DPHA (Nippon Kayaku Co., Ltd., trade name: KAYARAD DPHA) 7.5g
Phenothiazine 0.004g
Binder: Random copolymer of benzyl methacrylate / methacrylic acid = 78/22 molar ratio, molecular weight 38,000 1.0 g
Surfactant: 0.02 g of structure 1 shown in the above-mentioned surfactant 1 column
Solsperse 20000 (Avecia) 1.0g

  Next, the monomer liquid is slowly added to the stirring of the mixed dispersion obtained by mixing the Red pigment dispersions (R1), (R2), and (Y1) according to the formulation shown below. The mixture was stirred for 30 minutes at 0 ° C. to prepare a red inkjet ink (R ink 1).

Pigment dispersion R1 (C.I. Pigment Red 254) 30.6 g
Pigment dispersion R2 (CI Pigment Red 177) 10.5 g
4.6 g of pigment dispersion Y1 (CI Pigment Yellow 150)

  R inks 2 to 4 (present invention) and R inks 5 to 7 (comparative examples) were prepared according to the following Table 3 in the same manner as R ink 1 described above.

In Table 3, the meanings of the abbreviations in the solvent column and the boiling points of the solvents are as follows.
TPNP (tripropylene glycol n-propyl ether; boiling point 261 ° C.)
TEGDME (tetraethylene glycol dimethyl ether; boiling point 275 ° C.)
TPMA (Tripropylene glycol monomethyl ether acetate; boiling point 263 ° C)
TPNM (Tripropylene glycol n-methyl ether; boiling point 242 ° C.)

[Example 3]
-Red pixel formation by inkjet method-
In this example, ink was ejected in the following manner.
The inkjet head used was Dimatix SE-128, and the discharge control device used Dimatix Apollo II.
The inkjet head is mounted on an automatic two-dimensional moving stage (KS211-200 manufactured by Suruga Seiki), and the stage is moved from the head by the discharge control device while moving the stage so that a predetermined amount of ink is discharged into the gap between the partition walls produced above. The discharge was synchronized.
Here, the R ink 1 described above was filled in the head, and the ejection control device was controlled so that the ink landed at a predetermined position.
For droplet ejection, the ink composition is discharged until a desired concentration is reached, and after 30 seconds have elapsed from the discharge, the ink composition is heated and dried using a hot plate at 100 ° C. for 2 minutes, and then baked in an oven at 230 ° C. for 30 minutes. Thus, both the partition walls and the pixels were completely cured to produce a red pixel portion (R1a) for the color filter.
In addition, a red pixel portion (R1b) for a color filter was produced in the same manner as described above except that 10 minutes after the ink composition was discharged and dried at 100 ° C. for 2 minutes using a hot plate.
Next, the R inks 2 to 7 were filled in the head, and the color filter red pixel portions (R2a to R7b) were produced in the same procedure.

<Evaluation of flatness of pixel portion>
For the red pixel portions R1a to R7b, the shape profile of the pixel portion was measured using a non-contact type three-dimensional shape measuring apparatus Zygo manufactured by Zygo, and the height difference obtained by subtracting the minimum film thickness from the maximum film thickness was calculated.
Further, the difference between the shape profiles of the pixels a and b was evaluated according to the following criteria.
A: The shapes of a and b are similar. (Difference in height <0.3 μm)
Δ: Difference in height difference between a and b is 0.3 to 0.6 μm
X: The difference in shape between a and b is large. (Difference in height difference> 0.6μm)

<Evaluation of change in height of BM>
For the BM adjacent to the pixel part (concave part), the difference in height between the BM part before ink ejection and after ink curing is obtained using a Zygo non-contact type three-dimensional shape measuring device Zygo. The evaluation was based on the following criteria.

○: No change in BM height due to ink ejection.
(Change in height of BM before and after ink ejection <0.03 μm)
Δ: A slight change in the height of the BM due to ink ejection is recognized.
(Change in height of BM before and after ink ejection is 0.03 to 0.08 μm)
X: The change of the height of BM by ink discharge is recognized.
(Change in height of BM before and after ink ejection> 0.08 μm)

<Bulge on BM>
The state of the surface of the BM adjacent to the pixel portion after ink discharge drying was observed under reflected light with an optical microscope and evaluated according to the following criteria.
○: A dome-shaped bulge is not observed on the surface of the BM.
X: A dome-swelled portion is observed on the surface of the BM.

  The evaluation results are shown in Table 4.

[Example 4]
-Preparation of Green and Blue pigment dispersions-
In the preparation of the Red pigment dispersion of Example 2, the pigment of R1 was changed to C.I. I. Pigment Red 254 to C.I. I. Pigment Green 36 (trade name: Rionol Green 6YK, manufactured by Toyo Ink Manufacturing Co., Ltd.) was used in the same manner to prepare a Green pigment dispersion (G1).
Similarly, C.I. I. Pigment Red 254 15 parts by mass, C.I. I. Pigment Blue 15: 6 (trade name: Rionol Blue ES, manufactured by Toyo Ink Manufacturing Co., Ltd.) 13.5 parts by mass, C.I. I. Pigment Violet 23 (trade name: Hostaperm Violet RL-NF, manufactured by Clariant Japan Co., Ltd.) was used in the same manner as described above to prepare a pigment dispersion (B1) for Blue.
The Yellow pigment dispersion used for Green toning was the same as the Red pigment dispersion (Y1).
The number average particle diameters of the pigment dispersions G1 and B1 were 46 nm and 50 nm, respectively.

-Preparation of Green ink and Blue ink for color filter-
In the preparation of the red ink for the color filter of Example 2, the pigment dispersions G1 and Y1 were used, and the composition was changed to the composition shown in Table 5 below. 4 (invention) and G inks 5-7 (comparative examples) were prepared.
In addition, the color filter B inks 1 to 4 (present invention) and the B inks 5 to 7 (comparison) were performed in the same manner as in Example 2 except that the composition shown in Table 6 below was changed using the pigment dispersion B1. Example) was prepared. The units in Tables 5 and 6 are “g”.

[Example 5]
-Formation of green pixel portion and blue pixel portion by inkjet method-
The G pixel portions G1a to G7b and the B pixel portions B1a to B7b were produced in the same manner except that the G1 to G7 ink and the B1 to B7 ink were used instead of the R ink in the formation of the Red pixel portion in Example 3. .
When these pixel portions were evaluated in the same manner as in Example 3, when the green inks G1 to G4 and the blue inks B1 to B4 of the present invention were used, changes in the height of the BM due to ink ejection and the dome A good pixel portion with no shape bulge and small variation in shape was obtained, whereas when the inks of comparative examples G5 to G7 and B5 to B7 were used, all of them were satisfied. Thus, the same result as that obtained when the Red pixel portion was manufactured was obtained.

[Example 6]
<Production of color filter using RGB ink>
In Example 3, an inkjet color filter (CF1) in which RGB pixels were periodically repeated was produced in the same manner except that G ink 1 and B ink 1 were used in addition to R ink 1.
CF2 to CF7 were prepared in the same manner except that the R ink 1, G ink 1, and B ink 1 of CF1 were changed to R ink, G ink, and B ink corresponding to the respective CF numbers.

<Production of display device>
A transparent electrode of ITO (Indium Tin Oxide) was further formed on the color filter substrate (CF1) obtained above by sputtering. Separately, a glass substrate was prepared as a counter substrate, and patterning was performed for the PVA mode on the transparent electrode and the counter substrate of the color filter substrate, respectively.
A photo spacer was provided in a portion corresponding to the upper part of the partition wall on the ITO transparent electrode, and an alignment film made of polyimide was further provided thereon.
Then, a UV curable resin sealant is applied to the position corresponding to the outer wall of the partition wall surrounding the pixel group of the color filter by a dispenser method, and the PVA mode liquid crystal is dropped and bonded to the counter substrate. Thereafter, the bonded substrate was irradiated with UV, and then heat-treated to cure the sealing agent. Polarizing plates HLC2-2518 manufactured by Sanlitz Co., Ltd. were attached to both surfaces of the liquid crystal cell thus obtained. Next, a backlight of a cold cathode tube was constructed and arranged on the side of the back surface of the liquid crystal cell provided with the polarizing plate, whereby the liquid crystal display device 1 of the present invention was obtained.
Further, liquid crystal display devices 2 to 4 and 5 to 7 (comparative examples) of the present invention were produced in the same manner as described above except that CF1 was changed to CF2 to 7.

<Evaluation of unevenness of display device>
About the produced liquid crystal display devices 1-7, each RGB and the gray pattern were displayed, and the display nonuniformity was evaluated visually by the following references | standards. The results are shown in Table 7.
○: Unevenness is not observed.
Δ: Some unevenness is observed.
X: A considerably strong unevenness is observed.

  From these results, it is understood that when a color filter and a liquid crystal display device are produced using the ink for ink of a color filter of the present invention, excellent display quality can be obtained without display unevenness.

Claims (14)

An inkjet ink for a color filter that is applied to a recess surrounded by a partition formed on a substrate by an inkjet method and used for forming a pixel of a color filter,
At least a coloring pigment and an organic solvent, and the organic solvent is selected from the group consisting of tripropylene glycol monoalkyl ether, dipropylene glycol monoalkyl ether, tetraethylene glycol monoalkyl ether and triethylene glycol monoalkyl ether that the boiling point is observed including a 250 ° C. or more compounds, and an organic solvent having a boiling point of not lower than 230 ° C. at atmospheric pressure, non-aqueous color filter for an inkjet ink that occupy more than 80% by weight of the total organic solvent. Inkjet ink for color filter according to 請 Motomeko 1 solubility Ru der less 10g in water at 25 ° C. of the boiling point of 250 ° C. or more compounds. The boiling point of 250 ° C. or more compounds Ru tripropylene glycol monoalkyl ether der 請 Motomeko 1 or inkjet ink for color filter according to claim 2. The inkjet for color filters according to any one of claims 1 to 3, wherein the compound having a boiling point of 250 ° C or higher contains at least one of tripropylene glycol mono n-butyl ether and tripropylene glycol mono n-propyl ether. ink. It further contains a monomer having at least two polymerizable groups 請 Motomeko 1 to inkjet ink for color filter according to any one of claims 4. Said polymerizable group, an epoxy group, acryloyloxy group and methacryloyloxy color filter for an inkjet ink according to 請 Motomeko 5 Ru der one selected from the group consisting of an oxy group. Inkjet ink for color filter according to 請 Motomeko 5 or claim 6 compound accounts for more than 50% by weight of the monomer having a polymerizable group three or more. That further to contain a binder resin 請 Motomeko 1 to a color filter for an inkjet ink according to any one of claims 7. It further contains a surfactant 請 Motomeko 1 to a color filter for an inkjet ink according to any one of claims 8. Viscosity at 25 ℃ is Ru der following 5 mPa · s or more 30 mPa · s 請 Motomeko 1 to inkjet ink for color filter according to any one of claims 9. The recess surrounded by the barrier ribs formed on a substrate, to form the pixel by applying a droplet of the ink-jet ink for color filter according to any one of claims 1 to 10 by an inkjet method Luke A method for manufacturing a filter. After removing the organic solvent contained in the droplets to form an ink residue, a pixel is formed by polymerizing the ink residue by a step of irradiating the ink residue with active energy rays and / or a step of heating the ink residue. method for producing a color filter according to 請 Motomeko 11 you. Color filter manufactured by the method for producing a color filter according to claim 11 or claim 12. Viewing apparatus Ru comprising the color filter according to claim 13.