JP2012203157A - Inkjet ink for color filter - Google Patents

Abstract

【Task】
To provide a color filter inkjet ink capable of producing a color filter in which ink does not overflow from the inside of a pixel during ejection stability, ejection, or movement of a black matrix after ejection in color filter production using an inkjet method. means】
An ink-jet ink for a color filter, comprising at least two kinds of acrylic polymer compounds.
The color filter, wherein the acrylic polymer compound is a polymer compound having at least one acid value, and at least one polymer compound having no acid value having a weight average molecular weight of 1,000 to 10,000. Ink-jet ink, and a color filter using the above ink.
[Selection figure] None

Description

  The present invention relates to an ink-jet ink for a color filter and a color filter using the same.

  A liquid crystal display panel used for a thin television or the like includes a color filter substrate, a liquid crystal cell substrate, and a backlight unit as main components. The backlight unit is a light source provided on the back surface of the liquid crystal cell substrate. The liquid crystal of the liquid crystal cell substrate is filled between the TFT (thin film transistor) array substrate and the color filter substrate. On the color filter substrate, a repeating pattern of three primary colors (red, blue, green; RGB) is formed at a position facing each pixel of the TFT array substrate. A transparent electrode is provided on the entire surface of the color filter substrate, and the direction of the liquid crystal is controlled by the voltage with the pixel electrode of the TFT array substrate, and the amount of transmitted light is controlled.

  Specifically, the color filter substrate is formed by arranging three or more kinds of fine stripe filter segments of different hues in parallel or intersecting on the surface of a transparent substrate such as glass, or a fine mosaic shape. It consists of filter segments arranged in a constant array. A light shielding region (black matrix) having a certain width is provided between the filter segments in order to increase the display contrast of the color filter substrate. The width of the stripes constituting the color filter substrate and the length of one side of the mosaic are as fine as about 70 μm, and are arranged in a predetermined order for each hue. Moreover, the film thickness of a normal color filter substrate is 0.8 to 1.5 μm, and the pigment occupies 25 to 45% by weight in the filter segment.

Conventionally, a color filter substrate is manufactured by applying a photoresist solution in which a pigment is dispersed on a transparent substrate, and then repeating steps such as drying, exposure, development, and curing. Therefore, productivity is low and the demand for cost reduction is high. In particular, with the increase in size of liquid crystal display panels, a technique for replacing photoresist has been demanded.
In accordance with these requirements, manufacturing methods and manufacturing facilities have been reviewed, and the manufacture of color filter substrates by the ink jet method has attracted attention. The inkjet method is particularly advantageous in that the manufacturing apparatus can be easily downsized and the productivity is high. Furthermore, in recent years, due to the advancement of technology relating to printer heads and inks, pigment-based inks have begun to be used in the ink jet method, and as a result, light resistance and fastness have also been improved. Also from this point, various proposals have been made, in which it is advantageous to apply the ink jet method to color filter substrate applications.

  The formation of the filter segment by the ink jet method is performed by providing a black matrix on a transparent substrate in advance and filling the ink in the region divided by the black matrix by the ink jet method. An ink composition having physical properties that can be dispersed and contained at a high concentration in order to provide a pigment concentration necessary for a color filter substrate, and at the same time, can be stably ejected to a desired position on the substrate by an inkjet method. Has been developed.

However, when ejecting with an ink jet apparatus, the ink viscosity increases due to slight drying at the nozzle, leading to clogging of the nozzle. Furthermore, it is difficult to follow the movement of the piezo in the inkjet head unless the solid components in the ink are sufficiently dissolved in the solvent, and the molecular chains of the dissolved components are not sufficiently widened, resulting in uneven flight and stable ejection. Sexuality is impaired.
Furthermore, when the coating film is not dried and baked, if there is not enough fluidity, the pixels in the area divided by the black matrix become convex, resulting in poor pixel flatness, and compatibility of the ink composition. However, when the glass is not sufficiently wet, color unevenness occurs in the pixel. However, when the black matrix is easily wetted, there is a problem that the ink overflows from the pixel when the black matrix is ejected or when the black matrix is moved after the ejection.

For example, Japanese Patent Application Laid-Open No. 2010-8637 includes an acrylic polymer that defines a solubility parameter as a leveling agent, thereby suppressing density unevenness and color unevenness at each site, brightness, and contrast. A method is disclosed in which the ratio is good. Japanese Patent Application Laid-Open No. 2007-72283 discloses a method in which an acrylic surfactant is added to perform uniform drying, a difference in viscosity is suppressed, and the inside of a pixel is flattened. However, since the binder resin used above is not an acrylic polymer compound, it has poor compatibility with the acrylic polymer compound added as a leveling agent, resulting in poor ink storage stability. In addition, since the compatibility is poor, color unevenness occurs, resulting in a problem that the brightness and contrast ratio are deteriorated.
Further, in JP-A-2007-72283, an acrylic polymer compound and a silicon polymer compound are used in combination as a leveling agent, but the silicon polymer compound has good wetting and spreading to the black matrix and moved the black matrix after ejection. Occasionally, the ink overflowed from within the pixel, and the ink was mixed into the adjacent area, thereby impairing the hue of the filter segment.
In addition, in JP-A-2007-302863, a method in which discharge stability is excellent by using an acrylic polymerization compound having a weight average molecular weight of 30000 and an acrylic polymerization compound having a weight average molecular weight of 20000 as a binder resin and by defining a composition ratio having an appropriate fluidity. Is disclosed. However, when the composition ratio of the high molecular weight acrylic polymer compound is increased, there is a problem in that the fluidity of the ink at the time of ejection is poor and nozzle non-ejection occurs.

JP 2010-8638 A JP 2007-72283 A JP 2007-302863 A JP 2008-268884 A

  The present invention provides an inkjet ink for a color filter capable of producing a color filter in which ink does not overflow from the inside of a pixel at the time of ejection stability, ejection, or movement of a black matrix after ejection in color filter production using an inkjet method. The purpose is to do.

That is, this invention relates to the inkjet ink for color filters characterized by containing the at least 2 sort (s) of acrylic polymerization compound.
Further, the present invention is characterized in that the acrylic polymer compound is at least one polymer compound having an acid value, and at least one polymer compound having no acid value having a weight average molecular weight of 1,000 to 10,000. The present invention relates to an inkjet ink for a color filter, and a color filter using the inkjet ink.

  In the production of color filters using the inkjet method, it was possible to provide inkjet inks for color filters that can produce stable color filters that are stable in ejection.

  The ink-jet ink of the present invention is characterized by containing at least two kinds of acrylic polymerization compounds.

  In the present invention, preferably, in the acrylic polymer compound, at least one kind is a binder resin having an acid value, and at least one kind is a leveling agent having no acid value and having a weight average molecular weight of 1000 to 10,000. It is characterized by being.

  In general, the binder resin has an effect of maintaining a stable dispersion for obtaining ink storage stability. However, when the acid value is low, the electrical repulsion between the dispersions of the ink becomes weak and aggregates, so that it is stored. Stability is impaired. On the other hand, when the acid value is high, the electric repulsion becomes strong, the fluidity of the ink is deteriorated, and the discharge stability is deteriorated.

In general, the leveling agent has an effect of improving the wetting and spreading and uniform shape in the pixel by the orientation of the leveling agent on the ink surface in the pixel after being discharged into the pixel of the black matrix. If a leveling agent is used, the fluidity of the ink deteriorates and the ejection stability is impaired. In addition, there is no heat flow at the time of baking after discharge, and the in-pixel flatness is deteriorated.
Leveling agents include silicon leveling agents, fluorine leveling agents, and acrylic leveling agents, but silicon leveling agents and fluorine leveling agents tend to greatly reduce the surface tension and move the black matrix after ejection. Sometimes ink overflows from within the pixel.

  In the above binder resin, a stable dispersion is obtained in an acid value in the range of 40 to 120 mgKOH / g, and the leveling agent has a weight average molecular weight of 1000 to 10,000, and the fluidity of the ink is good. It became clear by the study by the present inventors. In addition, by using an acrylic polymer compound together with a binder resin and a leveling agent, the compatibility is good, so the storage stability is good, and the fluidity is good, so it is easy to follow the movement of the piezo in the inkjet head. Therefore, uneven flight or the like did not occur, and excellent stable ejection properties were easily obtained, and the in-pixel flatness was also good. Further, it has been clarified by the inventor that the pixel does not overflow when moving the black matrix after ejection, and the present invention has been completed.

  In addition, about the addition amount of a leveling agent, 0.01 to 5 weight% is preferable on the basis of the inkjet ink whole quantity, and 0.1 to 1 weight% is further more preferable.

  Moreover, about the addition amount of a binder, 5 to 30 weight% is preferable on the basis of the whole amount of inkjet ink, and 5 to 15 weight% is further more preferable.

  The solvent used in the present invention is selected from the viewpoints of solubility in resins, swelling action on apparatus members, viscosity, and ink drying properties in nozzles. For example, alcohol solvents, glycol solvents, ester solvents, ketones One type of solvent may be used alone, or two or more types may be mixed and used.

  Examples of the alcohol solvent include hexanol, heptanol, octanol, nonanol, decanol, undecanol, cyclohexanol, benzyl alcohol, amyl alcohol, and the like.

  Examples of glycol solvents include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monoisopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monohexyl ether, methoxymethoxyethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol. Monobutyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene group Monoethyl ether, propylene glycol isopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, 1-butoxyethoxy propanol, 1-methoxy-2-propyl acetate and the like.

Examples of the ester solvent include ethyl lactate, lactic acid propane, and butyl lactate.
Examples of the ketone solvent include cyclohexanone, ethyl amyl ketone, diacetone alcohol, diisobutyl ketone, isophorone, methylcyclohexanone, acetophenone, and the like.

  In particular, from the viewpoint of pigment dispersion performance and ink jet ink ejection properties, an alkylene glycol monoalkyl ether acetate solvent or an alkylene glycol diacetate solvent having a boiling point of 200 ° C to 300 ° C at room temperature is used as a single type. Alternatively, it is preferable to use 70% by weight or more as a mixed solvent of two or more kinds. In order to obtain better pigment dispersibility and ejection properties, diethylene glycol monoethyl ether acetate and 1,3-butylene glycol diacetate can be preferably used.

  It is preferable to use an ester-modified dispersion resin from the viewpoint of reducing the viscosity at the time of pigment dispersion. Lowering the viscosity is preferable because the concentration of the pigment in the ink can be improved, and the time required for the inkjet discharge process can be shortened, so that productivity can be improved.

  Further, a resin may be added as a binder. Selection of binder resin can be selected from inkjet aptitude and color filter aptitude. For example, by using a binder resin containing a phosphoric acid group described in JP-A No. 2007-169607, pigment dispersibility and an effect of lowering the viscosity of the dispersion paste can be obtained, which can be suitably used. Furthermore, in addition to the binder resin, by using the ester-modified resin in combination, it is possible to further reduce the viscosity and increase the contrast, and the ink can be suitably used for the ink for color filters.

Examples of the polymer used as the binder resin include (meth) acrylic resin, polyurethane resin, polyamide resin, polyester resin, epoxy resin, phenol resin, polycarbonate resin, polyvinyl butyral resin, polyvinyl formal resin, polyvinyl alcohol, polyethylene glycol, polyethylene oxide, Polypropylene glycol, shellac resin, vinyl resin, rubber resin, wax, and other natural resins can be used.
In particular, due to the compatibility with the acrylic leveling agent, by using an acrylic polymer resin as the binder resin, it is excellent in affinity and thixotropy, and the brightness can be increased. Further, the pixel flatness when ink is ejected to the black matrix opening and the wetting and spreading to the glass are good and can be suitably used. Furthermore, among these, it is preferable to use an acrylic polymer resin polymerized only with a monomer having an acrylic group (methacrylic group).

In addition, raw materials having unsaturated bonds such as monofunctional or polyfunctional monomers, oligomers, prepolymers, oils, leveling agents and the like can be appropriately contained.
In particular, when used for color filters, for example, an epoxy monomer or a monomer having an oxetane ring can be used to impart various resistances. These also enable cross-linking with active energy rays. Moreover, when using energy rays, such as an ultraviolet-ray, the initiator according to the reaction can also be used.

  The ink-jet ink of the present invention preferably contains a thermal crosslinking agent. This is because the UV exposure process is not required and the tact time is reduced. Specific examples of the thermal crosslinking agent include melamine compounds, benzoguanamine compounds, epoxy compounds, alkylated melamine resins, isocyanate compounds, and the like, and these can be used alone or in combination of two or more. Among these, it is preferable to contain melamine or a melamine derivative from the viewpoint of obtaining excellent coating film resistance.

Examples of the melamine compound include those having an imino group, a methylol group, and / or an alkoxymethyl group, and a melamine compound containing only an alkoxymethyl group is particularly preferable. Specific examples of the alkoxymethyl group-containing melamine compound include hexamethoxymethylol melamine or hexabutoxymethylol melamine.
The following can be mentioned as a specific example of the commercial item of a melamine compound. However, it is not necessarily limited to these. Nikarak MW-30M, MW-30, MW-22, MS-21, MX-45, MX-500, MX-520, MX-43, MX-302 manufactured by Sanwa Chemical Co., Ltd., Cymel 300 manufactured by Nihon Cytex Industries 301, 303, 350, 285, 232, 235, 236, 238, My Coat 506, 508, and the like.

  From the viewpoint of obtaining excellent flatness, the melamine compound is preferably contained in the ink composition in an amount of 1% by weight to 10% by weight, and preferably 1% by weight to 5% by weight. Particularly preferred. If the content exceeds 10% by weight or more, the crosslinking density of the coating film during baking becomes too high, and the flexibility of the coating film is impaired, so that it is difficult to satisfy excellent pixel flatness.

In the ink of the present invention, a dye or a pigment can be used as a colorant. Examples of the dye include acid dyes, basic dyes, direct dyes, reactive dyes, disperse dyes, metal-containing dyes, and the like, and they can be used alone or in combination as long as they do not contradict the purpose of the present invention.
In addition, as the pigment, those generally used as pigments, particularly when light resistance and weather resistance are required, quinacridone, anthraquinone, perylene, perinone, diketopyrrolopyrrole, Isoindolinone, condensed azo, benzimidazolone, monoazo, insoluble azo, naphthol, flavanthrone, anthrapyrimidine, quinophthalone, pyranthrone, pyrazolone, thioindigo, anthrone, dioxazine, Organic pigments such as phthalocyanine and indanthrone, metal complexes such as nickel dioxin yellow and copper azomethine yellow, metal oxides such as titanium oxide, iron oxide and zinc oxide, metal salts such as barium sulfate and calcium carbonate, carbon black And inorganic pigments such as aluminum and mica. In order to give a metallic feeling or a pearly feeling, metal fine powder such as aluminum or mica fine powder is used. Examples of the dye include azo series, quinoline series, stilbene series, thiazole series, indigoid series, anthraquinone series, and oxazine series.

  For example, C.I. I. Pigment Red 7, 9, 14, 41, 48: 1, 48: 2, 48: 3, 48: 4, 81: 1, 81: 2, 81: 3, 97, 122, 123, 146, 149, 168, 177, 178, 180, 184, 185, 187, 192, 200, 202, 208, 210, 215, 216, 217, 220, 223, 224, 226, 227, 228, 240, 246, 254, 255, 264, 272, or C.I. I. Pigment Yellow 1, 2, 3, 4, 5, 6, 10, 12, 13, 14, 15, 16, 17, 18, 20, 24, 31, 32, 34, 35, 35: 1, 36, 36: 1 37, 37: 1, 40, 42, 43, 53, 55, 60, 61, 62, 63, 65, 73, 74, 77, 81, 83, 86, 93, 94, 95, 97, 98, 100 , 101, 104, 106, 108, 109, 110, 113, 114, 115, 116, 117, 118, 119, 120, 123, 125, 126, 127, 128, 129, 137, 138, 139, 147, 148 , 150, 151, 152, 153, 154, 155, 156, 161, 162, 164, 166, 167, 168, 169, 170, 171, 172, 173, 174, 17 5, 176, 177, 179, 180, 181, 182, 185, 187, 188, 193, 194, 199, or C.I. I. Pigmentoranger 36, 43, 51, 55, 59, 61, C.I. I. Pigment Green 7, 10, 36, 37, C.I. I. Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, 15: 6, 16, 22, 60, 64, C.I. I. Pigment Violet 1, 19, 23, 27, 29, 30, 32, 37, 40, 42, 50 and the like can be mentioned, but the pigment is not limited thereto.

The ink-jet ink of the present invention may contain the above pigments alone or in combination of two or more.
Moreover, it is preferable to use a pigment from points, such as light resistance and water resistance.
A pigment derivative can be used to stably disperse the pigment. Examples of the pigment derivative include the general formula (2):
G ^1- (E) (2)
(In the formula, G ¹ is a chromogenic compound residue, and E is a basic substituent, an acidic substituent, or a neutral substituent)
If necessary to achieve the present invention, these compounds can be used alone or in combination with a plurality of pigment derivatives.
In addition, additives such as a leveling agent and an antifoaming agent can be appropriately mixed and used in the ink.

<Color filter substrate>
A color filter substrate can be produced by the inkjet method using the inkjet ink of the present invention. The color filter substrate can be used for, for example, a liquid crystal display panel used for a thin television or the like.
The color filter substrate is provided with a filter segment having a desired hue, and the filter segment ejects inkjet ink for a color filter by an inkjet method in a region divided by the black matrix of the substrate on which the black matrix is formed. Is formed.

As the substrate, a glass plate or a resin plate such as polycarbonate, polymethyl methacrylate, or polyethylene terephthalate can be used. The black matrix is formed on the substrate by, for example, a photolithography method in which a radical polymerization type black resist is applied, exposed, developed, and patterned, a printing method in which black ink is printed, or a vapor deposition method in which metal is evaporated and then etched. Can be formed.
In the post-baking step in the present invention, baking was performed at 230 ° C. for 20 minutes. However, the post-baking shown here refers to a step of substantially proceeding with crosslinking, and is not limited as long as it is generally performed at the time and temperature conditions.

[Example]
The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight”. Moreover, the weight average molecular weight of resin was measured using GPC and calculated | required in polystyrene conversion.

(1) Pigment Red Pigment A: C.I. I. Pigment Red 254 (Ciba Specialty Chemicals)
Red pigment B: C.I. I. Pigment Red 177 (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Green pigment: C.I. I. Pigment Glenn 36 (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Yellow pigment: C.I. I. Pigment Yellow 150 (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Blue pigment: C.I. I. Pigment Blue 15: 6 (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Violet pigment: C.I. I. Pigment Violet 23 (manufactured by Toyo Ink Manufacturing Co., Ltd.)
(2) Solvent CBAc: Diethylene glycol monoethyl ether acetate 1,3-BGDA: 1,3-butylene glycol diacetate BAC: Diethylene glycol monobutyl ether acetate

(3) Dispersing resin << Production Example 1 (Polyester Dispersant A) >>
A reaction vessel equipped with a gas introduction tube, a thermometer, a condenser, and a stirrer is charged with 62.6 parts of 1-dodecanol, 287.4 parts of ε-caprolactone, and 0.1 part of monobutyltin (IV) oxide as a catalyst. After substituting with nitrogen gas, the mixture was stirred with heating at 120 ° C. for 4 hours. The solid content measurement confirmed that 98% had reacted, and the first step was completed. To this reaction product, 36.6 parts of pyromellitic dianhydride was added and reacted at 100 ° C. for 5 hours. The acid value was measured to confirm that 97% or more of the acid anhydride had been half-esterified, and the second step was completed to prepare an ester-modified resin for pigment dispersion. The obtained ester-modified resin was used as Dispersant A.

(4) Acrylic polymer compound << Production Example 2 (Acrylic polymer resin A-1) >>
A temperature control regulator, a cooling tube, and a stirrer are attached to a separable 4 flask, charged with 100 parts of a solvent (propylene glycol monomethyl ether acetate), heated to 100 ° C. and purged with nitrogen in the reaction vessel. And the reaction was continued for 5 hours to obtain an acrylic resin solution (solid content 50%). The weight average molecular weight (Mw) of the obtained polymer was 10800, and the acid value (AV) was 86 mgKOH / g.
Methacrylic acid 11 parts
26 parts of 2-hydroxyethyl methacrylate
n 1-butyl methacrylate 60 parts Phosmer M 3 parts
2,2′-One azobisisobutyronitrile 5 parts of the obtained acrylic polymerization resin was designated as resin A-1.

<< Production Example 3 (Acrylic Polymerized Resin A-2 to A-5) >>
Blended as shown in Table 1 below, Acrylic Polymerized Resins A-2 to A-4 and Styrene-Acrylic Polymerized Resin A-5 were synthesized according to Production Example 2.
MA: Methacrylic acid 2-HEA: 2-hydroxylethyl acrylate n-BMA: n-butyl methacrylate iso-BMA: isobutyl methacrylate BzMA: benzyl methacrylate 2-EHMA: 2-ethylhexyl methacrylate MAA: methyl acrylate St: styrene

≪Production Example 4 (Polyester Polymer Compound B-1) ≫
A reactor equipped with a gas inlet tube, thermometer, condenser, and stirrer was charged with 62.6 parts of 1-dodecanol, 287.4 parts of ε-caprolactone, and 0.1 part of monobutyltin (IV) oxide as a catalyst, and replaced with nitrogen gas. The mixture was heated and stirred at 120 ° C. for 4 hours. After confirming that 98% had reacted by solid content measurement, 36.6 parts of pyromellitic anhydride was added and reacted at 120 ° C. for 2 hours to obtain a polyester polymer compound B-1. The obtained polyester polymerization compound B-1 was a white wax-like solid at room temperature.

≪Production Example 6 (Urethane Polymer Compound C-1) ≫
A reactor equipped with a gas introduction tube, a condenser, a stirring blade, and a thermometer was charged with 67 parts of 1-decanol and 433 parts of ε-caprolactone, and the reaction vessel was purged with nitrogen, followed by reaction at 120 ° C. for 2 hours. After completion of the reaction, it was diluted with 214 parts of methoxypropyl acetate to obtain a polycaprolactone solution (D).
A reactor equipped with a gas inlet tube, a condenser, a stirring blade, and a thermometer was charged with 250 parts of butyl methacrylate and 250 parts of benzyl methacrylate, the inside of the reaction vessel was purged with nitrogen, the temperature was raised to 80 ° C., and thioglycerol (Asahi) Chemical Industry Co., Ltd.) 38 parts was added dropwise over 10 minutes and reacted for 7 hours. After completion of the reaction, an acrylic resin solution (E) was obtained by diluting with 214 parts of methoxypropyl acetate.

In a reactor equipped with a gas introduction tube, a condenser, a stirring blade, and a thermometer, 53 parts of polycaprolactone solution (D), 67 parts of VESTANAT T 1890/100 (Degussa Japan Co., Ltd.), 55 parts of acrylic resin solution (E) Then, 103 parts of methoxypropyl acetate was charged and the inside of the reaction vessel was purged with nitrogen, and then heated to 80 ° C. and reacted for 1 hour. Then, 27 parts of dimethylolbutanoic acid (DMBA, Nippon Kasei Co., Ltd.) and 27 parts of methoxypropyl acetate were added and reacted at 90 ° C., and the disappearance of the 2270 cm ⁻¹ peak based on the isocyanate group was confirmed by IR And cooled to 40 ° C. to obtain a branched urethane polymer compound C-1.

(5) Preparation of pigment dispersion paste A pigment dispersion paste was prepared using the raw materials and blending amounts shown in Table 2 below.
Specifically, after the dispersant and the dispersion resin were dissolved in a solvent, the pigment was sufficiently mixed, diluted with the same solvent to a solid content of 25%, and then wet dispersed with a sand mill to prepare a pigment dispersion paste.

(6) Melamine resin Alkoxyalkyl group-containing melamine resin Nicalac Mx-43 (manufactured by Sanwa Chemical Co., Ltd.)

[Adjustment of carbon black resist]
60 parts of carbon black dispersion, 4.3 parts of trimethylolpropane triacrylate (“NK ester ATMPT” manufactured by Shin-Nakamura Chemical Co., Ltd.), photopolymerization initiator 2-benzyl-2-dimethylamino-1- (4-morpholino) Phenyl) -butanone-1 (“Irgacure 369” manufactured by Ciba Geigy) 2 parts, sensitizer (“EAB-F” manufactured by Hodogaya Chemical Co., Ltd.) 0.4 part, and cyclohexanone 21.6 parts, ink repellent (Toyo Ink) A mixture of 0.9 part of “Full Shade FSA-RCS001” manufactured by Manufacturing Co., Ltd. was uniformly stirred and mixed, and then filtered through a 1 μm filter to prepare a photosensitive black composition.

[Pattern formation]
The photosensitive black composition was applied to a 10 cm × 10 cm glass substrate by spin coating, and then dried at 70 ° C. for 15 minutes to form a coating film having a dry film thickness of 2 μm. Thereafter, ultraviolet rays were exposed to 200 mJ / cm ² through a photomask using an ultrahigh pressure mercury lamp. Next, the unexposed area was spray-developed using an aqueous sodium carbonate solution, washed with ion-exchanged water to remove the unexposed area, and post-baked at 230 ° C. for 30 minutes. The obtained BM had openings of approximately 100 μm in length and 300 μm in width.

・ Evaluation method [Evaluation: Color filter production by inkjet discharge]
The obtained ink is filled into SII 512 head (nominally 12 pl / 1 drop) or Konica KM 512 head (nominal 42 pl / 1 drop), and the ink is applied to the pixel while increasing the number of discharges one drop at a voltage of 25 V to the BM opening. And a pixel filled with ink to the desired density was created. Thereafter, the glass substrate was dried at 100 ° C. for 5 minutes so as not to spill ink due to vibration or wind pressure, and further baked at 230 ° C. for 30 minutes to produce a color filter provided with a colored layer.

-Discharge stability Continuous stable discharge evaluation was performed using the inkjet equipment. In this evaluation, discharging was continuously performed from all 128 nozzles, printing was performed on plain paper every 10 minutes, and the state of printing was observed. The content of the evaluation was that when the printing interval varied, it was determined that the liquid droplets were unevenly flying, and it was determined that the head clogging occurred in the portion lacking dots. Evaluation of the discharge was continued for up to 60 minutes. ○: Good discharge is possible up to 60 minutes. (Excellent discharge performance, practically no problem level. Δ: Good discharge up to 40 minutes is possible. Practically usable level)
×: Uneven flight or clogging occurs within 5 minutes (practically unusable level)
Storage stability The viscosity after heating for 7 days in a 45 ° C oven was measured.
○: Thickening rate of less than 10% compared to the viscosity before heating Δ: Thickening rate of 10% or more and less than 30% compared to the viscosity before heating X: Thickening rate of 30% compared to the viscosity before heating Overflow / Spillover Using the above inkjet equipment, the ease of overflow from BM was evaluated. In this evaluation, when the pixel was filled with ink while increasing the number of ejections by 10 drops to the BM opening, the ease of overflow was evaluated by the number of drops when overflowing from the BM opening. Evaluation is as described below.
○: Overflow drop number is 170 drops or more △: Overflow drop number is 140 drops or more and less than 170 drops ×: Overflow drop number is less than 140 drops

<Example 1>
32 parts by weight of pigment dispersion paste A, 27 parts by weight of pigment dispersion paste B, 30 parts by weight of solvent (CBAc), 4 parts by weight of melamine resin (Mx-43) 7 parts by weight of acrylic polymer resin A-1 As a leveling agent, 0.1 part by weight of acrylic polymer resin A-2 was added and mixed. Finally, pressure filtration was performed with a membrane filter to obtain an inkjet ink. The composition is shown in Table 3.
<Examples 2 to 13 and Comparative Examples 1 to 3>
As shown in Tables 3 and 4, inkjet inks were prepared in the same manner as in Example 1 except that the types and amounts of the constituent components were changed. The evaluation results of Examples 1 to 13 and Comparative Examples 1 to 3 are shown in Tables 5 and 6, respectively.

Claims (3)

  An ink-jet ink for a color filter, comprising at least two kinds of acrylic polymer compounds.   The acrylic polymerization compound according to claim 1, wherein at least one kind is a polymerization compound having an acid value, and at least one kind is a polymerization compound having no acid value having a weight average molecular weight of 1,000 to 10,000. Inkjet ink for color filters. A color filter using the inkjet ink for a color filter according to claim 1.