JP2007284590A - Polyhalogenated metal phthalocyanine crude pigment, the pigment and color filter containing the pigment in green pixel part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a color filter enabling liquid crystal display having higher contrast, a brominated metal phthalocyanine pigment suitable for forming a green pixel part of the color filter, and a crude pigment of the precursor thereof. <P>SOLUTION: The polyhalogenated metal phthalocyanine crude pigment has 0.10-1.50% content of tetrabromophthalimide (TBPI). The polyhalogenated metal phthalocyanine pigment is obtained by forming the crude pigment into fine powder, and has 0.10-1.50% content of the TBPI and 10-100 nm average primary particle diameter. The color filter having more superior contrast is obtained when the pigment is contained in the green pixel part of the color filter. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a polyhalogenated metal phthalocyanine crude pigment, the same pigment, and a color filter containing the same pigment in a green pixel portion.

Examples of the polyhalogenated metal phthalocyanine pigment for forming the green pixel portion of the color filter include C.I. I. Polyhalogenated copper phthalocyanine pigments containing bromine atoms such as CI Pigment Green 36 are well known. Recently, in order to secure a wider color gamut and improve the color reproducibility of liquid crystal displays, the use of polyhalogenated dissimilar metal phthalocyanine pigments whose central metal is zinc other than copper has been proposed (Patent Literature). 1-3.)

Such a polyhalogenated dissimilar metal phthalocyanine pigment has been removed as a color filter so as not to decrease the voltage holding ratio, thereby removing various metal ions and halogen ions.

However, when refining with a focus on metal ions or halogen ions, there is a disadvantage that the contrast is deteriorated.

JP 2003-47815 A JP 2004-70342 A JP 2004-70343 A

The problem to be solved by the present invention is to provide a color filter capable of displaying liquid crystal with higher contrast, a polyhalogenated metal phthalocyanine pigment suitable for forming a green pixel portion of the color filter, and a crude pigment as a precursor thereof. There is to do.

The inventors of the present invention have intensively studied about a brominated halogen-containing polyhalogenated metal phthalocyanine pigment, which is superior in contrast.If the content of tetrabromophthalimide contained in the polyhalogenated metal phthalocyanine pigment is within a specific range, It has been found that the problem can be solved, and the present invention has been completed.

That is, the present invention provides a polyhalogenated metal phthalocyanine crude pigment for a color filter green pixel portion having a tetrabromophthalimide content of 0.10 to 1.50%. The present invention also provides a polyhalogenated metal phthalocyanine pigment for a color filter green pixel portion having a tetrabromophthalimide content of 0.10 to 1.50% and an average primary particle size of 10 to 100 nm. Furthermore, the present invention provides a color filter in which the pigment is contained in a green pixel portion.

The polyhalogenated metal phthalocyanine crude pigment of the present invention contains a specific amount of tetrabromophthalimide, so that when it is incorporated in the green pixel portion of the color filter by finer processing, a color filter with better contrast can be obtained. There is an especially remarkable effect that a pigment is obtained. In addition, the polyhalogenated metal phthalocyanine pigment of the present invention contains a specific amount of tetrabromophthalimide and has a specific average primary particle diameter, so that when it is contained in the green pixel portion of the color filter, it has a better contrast. There is a particularly remarkable effect that a color filter can be obtained. Furthermore, the color filter of the present invention contains a specific amount of tetrabromophthalimide, and a polyhalogenated metal phthalocyanine pigment having a specific average primary particle diameter is included in the green pixel portion, so that a liquid crystal display with superior contrast is possible. It has a particularly remarkable effect.

Hereinafter, the present invention will be described in detail.

The polyhalogenated metal phthalocyanine is a known substance, and examples thereof include polychlorocopper phthalocyanine, polybromocopper phthalocyanine, polybromochlorocopper phthalocyanine, polychlorozinc phthalocyanine, polybromozinc phthalocyanine, polybromochlorozinc phthalocyanine. Examples of the polyhalogenated metal phthalocyanine pigment include C.I. I. And CI Pigment Green 7 and 36, and polybromochlorozinc phthalocyanine pigment.

When the number of chlorine atoms and / or bromine atoms bonded in the molecule increases, the color of the polyhalogenated metal phthalocyanine changes from blue to green. In order for the polyhalogenated metal phthalocyanine to become green, the number of halogen atoms bonded to the molecule is preferably 8 or more.

The polyhalogenated metal phthalocyanine has a total of 8 to 15 chlorine atoms and / or bromine atoms on four benzene rings per phthalocyanine molecule (structure) in that a yellowish and lighter green color is obtained. A structure in which a hydrogen atom is bonded to a halogen atom and the remainder thereof is preferable, and among them, a structure in which 9 to 15 atoms per phthalocyanine molecule and a hydrogen atom is bonded to the remainder is more preferable. A structure in which 13 to 15 bromine atoms per one and the remaining hydrogen atoms are bonded is particularly preferable. Moreover, as a halogen atom, it is preferable that more bromine atoms are contained than a chlorine atom in order to obtain a more yellowish green color. The central metal of the polyhalogenated metal phthalocyanine is preferably zinc (Zn) as compared with aluminum (Al) because the color difference (ΔE) before and after receiving the thermal history is smaller and the heat resistance of coloring is excellent. .

An optimal polyhalogenated metal phthalocyanine pigment is a polybromochlorozinc phthalocyanine pigment represented by the following general formula 1.

(In the general formula 1, all of X _{1 to} X ₁₆ are independently a chlorine atom, a bromine atom or a hydrogen atom. However, the total of chlorine atoms and bromine atoms bonded to the ring is 13 to 15, and the rest Is a hydrogen atom.)

The polyhalogenated metal phthalocyanine pigment of the present invention preferably has an average primary particle size of 10 to 100 nm. The average primary particle diameter in the present invention refers to 50 particles of pigment primary particles constituting aggregates on a two-dimensional image obtained by photographing particles in the field of view with a transmission electron microscope JEM-2010 (manufactured by JEOL Ltd.). Each of the longer diameters (major axis) is obtained and averaged. At this time, the pigment of the present invention as a sample is ultrasonically dispersed in a solvent, and then the particles are photographed with the microscope. A scanning electron microscope may be used instead of the transmission electron microscope.

The effect of the present invention is manifested by the specific content of tetrabromophthalimide (hereinafter referred to as TBPI) contained in the polyhalogenated metal phthalocyanine pigment.

Conventionally, color filter characteristics have been improved by reducing the amount of positive and negative ion components contained in the pigment by refining. The polyhalogenated metal phthalocyanine is insoluble or hardly soluble in water and organic solvents, and the relationship between the content of such insoluble and hardly soluble nonionic components and the color filter characteristics has not been elucidated. As a result of trial and error, the present inventors have come to focus on TBPI as this nonionic component.

Although the reason is not clear, TBPI is more contained in polyhalogenated metal phthalocyanine containing a bromine atom as a substituent. This is because polyhalogenated metal phthalocyanines containing bromine atoms as substituents use bromine sources such as bromine and iron bromide in the production process, and side reactions occur in addition to phthalocyanine ring formation reactions. Or because of disassembly for some reason.

The method for calculating the TBPI content in the polyhalogenated metal phthalocyanine pigment is as follows. First, TBPI is purchased as a reagent and dissolved in a solvent so as to have various concentrations, and then a calibration curve showing the relationship between the content and the peak area is prepared by high performance liquid chromatography (HPLC). Thereafter, the polyhalogenated metal phthalocyanine pigment to be measured is immersed in a solvent and loosened with ultrasonic waves, the filtrate is separated with a filter paper, and the peak area based on TBPI of the filtrate is measured by HPLC. From this peak area, the TBPI content in the polyhalogenated metal phthalocyanine pigment is calculated from a calibration curve.

The polyhalogenated metal phthalocyanine pigment of the present invention has a TBPI content of 0.10 to 1.50%, and a higher contrast based on the resulting color filter, in particular, a TBPI content of 0.10 to 1.00%. It is preferable.

The polyhalogenated metal phthalocyanine pigment of the present invention may be a single polyhalogenated metal phthalocyanine pigment having one central metal, or a mixture of two or more polyhalogenated metal phthalocyanine pigments having different central metals. There may be. However, only the polybromochlorozinc phthalocyanine pigment> polyhalogenated metal phthalocyanine pigment mixture mainly composed of polybromochlorozinc phthalocyanine pigment> only polybromochlorocopper phthalocyanine pigment in that the color filter obtained has a wider RGB color gamut. It is preferable that it is on the left in the order.

In the polyhalogenated metal phthalocyanine pigment of the present invention, by defining the TBPI content in a predetermined range, not only the dispersibility to the resin but also the dispersion stability is improved, and the fluidity and storage stability of the pigment dispersion are excellent. As a result, the contrast of the coating film of the color filter green pixel portion is improved. Incidentally, the conventional polyhalogenated copper phthalocyanine pigment is not suitable for use in forming a color filter green pixel portion because the viscosity of the pigment dispersion is remarkably increased, making it difficult to disperse the pigment.

The polyhalogenated metal phthalocyanine pigment of the present invention satisfying a specific TBPI content and a specific average primary particle size is obtained from the polyhalogenated metal phthalocyanine pigment satisfying only the specific average primary particle size by means of extraction or washing. It can also be obtained by removing TBPI, but the TB inside the pigment particles
Since it takes time and labor to reduce the PI, the polyhalogenated metal phthalocyanine crude pigment satisfying only the specific TBPI content described above is pigmented by a known and conventional means so that TBPI does not enter. It is more preferable to obtain by.

That is, due to pigmentation so that TBPI does not mix, a crude polyhalogenated metal phthalocyanine pigment having a TBPI content of 0.10 to 1.50% can easily be used with a TBPI content of 0.10 to 1.50%. Certain polyhalogenated metal phthalocyanine pigments are obtained.

The polyhalogenated metal phthalocyanine crude pigment of the present invention is a green crude pigment containing coarse particles immediately after synthesis, which is a known and commonly used production method such as an aluminum chloride method, a chlorosulfonic acid method, a halogenated phthalonitrile method, etc. Can be manufactured.

In any of the above production methods, the reaction mixture containing the polyhalogenated metal phthalocyanine obtained after completion of the reaction is poured into an acidic aqueous solution such as water or hydrochloric acid, for example, to obtain a polyhalogenated metal phthalocyanine crude pigment. Precipitate. After filtering this crude pigment, it is washed with water or an alkaline aqueous solution such as an aqueous sodium hydrogen sulfate solution, an aqueous sodium hydrogen carbonate solution or an aqueous sodium hydroxide solution, and if necessary, acetone, toluene, methyl alcohol, ethyl alcohol, dimethylformamide, etc. In order to make a crude pigment into the above-mentioned specific TBPI content range, it is preferable to wash with an organic solvent. The cleaning liquid medium, the amount of cleaning liquid, and the number of times of cleaning may be determined by a trial and error method, and can generally be determined by measuring the TBPI content range for each cleaning condition.

For the measurement of the TBPI content in the crude pigment, the same method as in the case of the pigment described above can be adopted. The TBPI content in the polyhalogenated metal phthalocyanine can be more easily reduced by removing TBPI contained in a relatively large amount in the state of a crude pigment rather than a pigment. Thus, the crude polyhalogenated metal phthalocyanine pigment of the present invention is obtained.

The polyhalogenated metal phthalocyanine pigment of the present invention can be easily obtained by pigmenting the crude polyhalogenated metal phthalocyanine pigment of the present invention. In this case, as a pigmentation method, for example, a known and commonly used solvent boiling Method or solvent salt milling method can be employed.

Among them, the solvent salt milling can easily suppress the crystal growth of the pigment, and the polyhalogenated metal phthalocyanine pigment that is suitable for patterning the green pixel part of the color filter with the average primary particle diameter and aspect ratio in a specific range can be easily used. It is preferable at the point obtained.

The polyhalogenated metal phthalocyanine pigment of the present invention is preferably composed of particles having a non-directional aspect ratio as close to 1 as possible in terms of excellent fluidity. The pigment of the present invention composed of pigment particles having such an aspect ratio can be obtained more easily by the solvent salt milling method. In the solvent salt milling method, in controlling the crystal, there is a tendency to remove foreign substances present in the particles from the inside of the particles, and the salt and solvent are removed after the polyhalogenated metal phthalocyanine pigment is isolated. Since an additional step is provided, the effect of reducing the TBPI content in the second stage pigment can be expected as compared with the TBPI content in the pigment in the crude pigment stage. In view of these various aspects, it is clear that the solvent salt milling method is preferably employed for pigmentation of the crude polyhalogenated metal phthalocyanine pigment of the present invention.

The polyhalogenated metal phthalocyanine pigment of the present invention is obtained by subjecting a crude polyhalogenated metal phthalocyanine pigment having a TBPI content of 0.10 to 1.50% to solvent salt milling in the presence of a water-soluble inorganic salt and an organic solvent. Is obtained.

Examples of the water-soluble inorganic salt used in the present invention include inorganic salts such as sodium chloride, potassium chloride and sodium sulfate, and those having an average particle diameter of 0.3 to 50 μm are preferably used.

In order to obtain a polyhalogenated metal phthalocyanine pigment having an average primary particle size of 10 to 100 nm, the magnification of the water-soluble inorganic salt is preferably 10 to 30 times that of the crude pigment. Considering the productivity and economy, it is more preferably 11 to 20 times. The magnification of the water-soluble inorganic salt refers to the number of parts of the water-soluble inorganic salt per part of the crude pigment in terms of mass, and the unit is represented by double.

The organic solvent used in the present invention is preferably a water-soluble organic solvent capable of suppressing crystal growth, such as diethylene glycol, glycerin, ethylene glycol, propylene glycol, liquid polyethylene glycol, liquid polypropylene glycol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol, triethylene glycol monomethyl ether, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monomethyl Ether, dipropylene glycol, and the like. These can be used alone or in combination of two or more.

The amount of the organic solvent used is not particularly limited, but is preferably in the range of 0.01 to 5 parts per 1 part of the crude pigment in terms of mass.

Solvent salt milling means that a crude pigment, a water-soluble inorganic salt, and an organic solvent that does not dissolve it are mechanically kneaded and ground. Examples of means for kneading and grinding at this time include kneaders such as a kneader, a mix muller, an extruder, a ball mill, and a roll mill.

The conditions for the solvent salt milling treatment of the present invention are not particularly limited, but it is preferable to carry out the treatment in a state where the crude pigment is heated, that is, when it is hot. The temperature of the solvent salt milling treatment is preferably in the range of 30 to 150 ° C, and more preferably in the range of 80 to 110 ° C. The time for the solvent salt milling treatment is preferably in the range of 3 to 20 hours, and more preferably in the range of 4 to 10 hours.

Thus, a kneaded mixture containing the polyhalogenated metal phthalocyanine pigment of the present invention, a water-soluble inorganic salt, and an organic solvent as main components can be obtained.

In order to obtain the polyhalogenated metal phthalocyanine pigment of the present invention, the water-soluble inorganic salt and the organic solvent contained in the kneaded mixture may be removed. Although it does not specifically limit as the removal, For example, the following methods are mentioned. First, the kneaded mixture is poured into about 5 to 20 times the amount of water or warm water (compared to the kneaded mixture), and the mixture is dissolved for a certain period of time, and the aqueous slurry is filtered. Next, the water is washed several times until the specific conductivity of the filtrate is comparable to that of purified water (in order to make the concentration as close to zero as possible without containing free ion components in the pigment) and water-soluble inorganic salts and organic solvents And are completely removed. In addition, for these removals, if necessary, it can also be washed using an acid or alkaline aqueous solution. The water-soluble inorganic salt and organic solvent removed here can be recovered and reused.

For drying after filtration and washing, for example, dehydration and / or desolvation of the wet polyhalogenated metal phthalocyanine pigment of the present invention by heating at 80 to 120 ° C. with a heating source installed in a dryer, freeze drying, or the like is performed. Use of batch-type or continuous-type drying is possible. Examples of the dryer include a box dryer, a band dryer, and a spray dryer.

The pulverization after drying is not an operation for increasing the specific surface area of the polyhalogenated metal phthalocyanine pigment of the present invention or reducing the average particle diameter or aspect ratio of the primary particles, but a box dryer or band drying. When the pigment composition becomes a lamp shape or the like using a machine or the like, this is an operation for solving this and making it into powder. Examples of the pulverizer include a mortar, a hammer mill, a disk mill, a pin mill, a jet mill, and a juicer mixer.

Thus, by passing through the steps of filtration, washing, drying, and pulverization described above, the average primary particle diameter is in the range of 10 to 100 nm and the specific TBPI content of the green pixel portion of the color filter of the present invention. A dry powder of polyhalogenated metal phthalocyanine pigment suitable for pattern formation can be prepared. An excellent color filter can be prepared by incorporating the polyhalogenated metal phthalocyanine pigment of the present invention in the green pixel portion of the color filter.

Since the polyhalogenated metal phthalocyanine pigment of the present invention has the above average primary particle size and TBPI content, the pigment is finely dispersed in the liquid medium, and the dispersibility and dispersion stability of the pigment are improved. A pigment dispersion using this pigment composition is excellent in fluidity because of its low viscosity immediately after production and after aging. In addition, this pigment dispersion is excellent in storage stability because of a small change in viscosity immediately after production and after aging.

When such a pigment dispersion is used to produce a color filter green pixel portion, the coating properties of the green pixel portion are excellent, and a coating film with a uniform film thickness can be formed to obtain a color filter with high contrast. I can do it. Here, the contrast is the transmitted light intensity when the object to be measured is sandwiched with the polarization directions of the two polarizing plates parallel to each other and the object to be measured is sandwiched with the polarization direction of the two polarizers perpendicular to each other. This is divided by the transmitted light intensity and is also called depolarization.

In addition, when the average primary particle diameter of the polyhalogenated metal phthalocyanine pigment is less than 10 nm, the cohesiveness of the pigment becomes strong and difficult to disperse, the viscosity of the pigment dispersion increases with time, thixotropy appears strongly, etc. However, in the dispersed state, secondary particles having a larger particle size may be formed, which causes a decrease in the contrast of the color filter coating film. On the other hand, even if the average primary particle diameter of the polyhalogenated metal phthalocyanine pigment exceeds 100 nm, it is the same as described above. Moreover, even when the amount of TBPI deviates from the above range, it is the same as described above.

That is, when the average primary particle size and TBPI content deviate from the ranges defined in the present invention, the fluidity and storage stability of a pigment dispersion prepared using such a polyhalogenated metal phthalocyanine pigment are lowered. Cause. Due to this, the color filter green pixel portion using this pigment dispersion is not preferable because the contrast of the coating film is lowered.

The polyhalogenated metal phthalocyanine pigment of the present invention has a property that the primary particles of the pigment are less cohesive and easier to break than the conventionally known copper halide phthalocyanine pigment or the same pigment treated with an acetate ester compound. From the electron micrograph, it is possible to observe primary pigment particles that cannot be observed with the above-described conventionally known pigments or treated pigments.

In addition, when the polyhalogenated metal phthalocyanine pigment has a TBPI content within the specified range of the present invention, the flow characteristics in the photocurable composition described later tend to improve, and the viscosity of the photocurable composition tends to decrease. is there. As a result, the applicability of the color filter to the transparent substrate is also improved.

The polyhalogenated metal phthalocyanine pigment of the present invention has an average primary particle size in the above-mentioned range as compared with a conventionally known polyhalogenated copper phthalocyanine pigment or the same pigment treated with an acetate ester compound, and the particle size of the pigment. The distribution is narrower and sharper (light scattering by coarse particles is less). In addition, there are few fine irregularities on the surface of the pigment, and the smoothness of the pigment surface also improves the dispersibility and dispersion stability of the pigment. A pixel portion can be obtained.

The color filter green pixel portion obtained using the polyhalogenated metal phthalocyanine pigment of the present invention is obtained from the result of visual evaluation from a conventionally known polyhalogenated copper phthalocyanine pigment or the same pigment treated with an acetate ester compound. The hue is further yellowish than the green pixel portion thus obtained, and a green color with excellent transparency is exhibited.

The polyhalogenated metal phthalocyanine pigment of the present invention includes a conventionally known pigment dispersant or interface for the purpose of improving the dispersibility of the pigment in the photocurable composition for forming the green pixel portion of the color filter. An activator or a pigment derivative may be used in an amount of about 1%. Specifically, examples of the pigment derivative include a low halogenated copper phthalocyanine sulfonic acid derivative.

In addition, the polyhalogenated metal phthalocyanine pigment of the present invention can be used in combination with a yellow pigment as necessary in order to adjust (yellowish) to a desired chromaticity for forming a color filter green pixel portion. . These yellow pigments are preferably added in a range that does not impair the color characteristics. These yellow pigments may be surface-treated yellow pigments whose surface is covered with a known and commonly used pigment derivative, dispersant, surfactant, resin, or other surface treatment agent. Good. Further, the yellow pigment adjusted to the same particle diameter as that of the polyhalogenated metal phthalocyanine pigment of the present invention or a yellow-treated pigment thereof may be used.

The yellow pigment used in combination with the present invention can be used as a color filter green pixel portion in order to pick up a desired emission line of a backlight light source having a wavelength (Tmax) that maximizes the transmittance of the spectral transmission spectrum.

Examples of the yellow pigment for toning used in the present invention include C.I. I. Pigment yellow 83, 128, 138, 139, 150, 154, 180, 185 and the like.

These yellow pigments can be used singly or in combination of two or more. Among the yellow pigments, C.I. I. Pigment Yellow 138, 139, and 150 are preferable in terms of excellent chromaticity and transparency.

The content ratio of the yellow pigment can be appropriately selected depending on the application. In general, when used for color filter applications, it is preferably in the range of 10 to 60%, in terms of mass, with respect to the total amount of the polyhalogenated metal phthalocyanine pigment and yellow pigment of the present invention, More preferably, it is in the range of 50%.

According to the polybromochlorozinc phthalocyanine pigment suitable in the present invention, a small amount is sufficient even when the yellow pigment is used in combination with the pigment, so that compared with the conventional case where two or more different color pigments are mixed for toning. Thus, reaggregation of the pigment hardly occurs and turbidity is small. In addition, a color filter green pixel portion having excellent chromaticity and transparency can be obtained. Furthermore, when the polyhalogenated metal phthalocyanine pigment of the present invention is used in combination with the yellow pigment, there is a disadvantage that a portion having the intended chromaticity and hue in the color filter green pixel portion and a portion not being formed are formed. This is preferable because it is difficult to occur.

The color filter green pixel portion prepared by using the polyhalogenated metal phthalocyanine pigment of the present invention in combination with a yellow pigment comprises a conventionally known polyhalogenated copper phthalocyanine pigment, or the same pigment treated with an acetate ester compound as a yellow pigment. Is preferable in that the decrease in brightness when a liquid crystal display is used is small, and the amount of light transmission in the green region is large.

The polyhalogenated metal phthalocyanine pigment of the present invention can be used for preparing a green pixel portion of a color filter and a green pigment composition for the green pixel portion by a conventionally known method. In producing the color filter green pixel portion using the polyhalogenated metal phthalocyanine pigment of the present invention, a pigment dispersion method can be suitably employed.

A typical method in this method is a photolithography method, in which a photocurable composition to be described later is applied to a surface of a transparent substrate for a color filter provided with a black matrix, and is heated and dried (prebaked). After that, pattern exposure is performed by irradiating ultraviolet rays through a photomask to cure the photo-curable compound at a location corresponding to the pixel portion, and then developing the unexposed portion with a developer to remove non-pixels. This is a method of removing the portion and fixing the pixel portion to the transparent substrate. In this method, a pixel portion made of a cured colored film of a photocurable composition is formed on a transparent substrate.

A photocurable composition to be described later is prepared for each color of red, green, and blue, and a color filter having red, green, and blue colored pixel portions at predetermined positions is manufactured by repeating the above-described operation. I can do it. As described above, a green pixel portion and a green pigment composition for the green pixel portion can be prepared from the polyhalogenated metal phthalocyanine pigment of the present invention. In addition, in order to prepare the photocurable composition for forming the red pixel portion and the blue pixel portion, known and commonly used red pigments and blue pigments can be used, respectively.

Examples of the pigment for forming the red pixel portion include C.I. I. Pigment Red 122, 123, 149, 177, 179, 209, 254, and the like are pigments for forming the blue pixel portion. I. Pigment blue 15: 1, 15: 2, 15: 6, and the like. For the formation of the red pixel portion, a yellow pigment can be used together with the green pixel portion, and for the formation of the blue pixel portion, a purple pigment or a blue pigment having a more red hue can be used in combination. Thereafter, if necessary, the entire color filter can be heat-treated (post-baked) in order to thermally cure the unreacted photocurable compound.

Examples of a method for applying a photocurable composition described later on a transparent substrate such as glass include a spin coat method, a roll coat method, and an ink jet method.

Although the drying conditions of the coating film of the photocurable composition apply | coated to the transparent substrate differ also with the kind of each component, a compounding ratio, etc., they are 50-150 degreeC and are about 1 to 15 minutes normally. This heat treatment is generally referred to as “pre-baking”. Moreover, as light used for photocuring of a photocurable composition, it is preferable to use the ultraviolet-ray of a wavelength range of 200-500 nm, or visible light. Various light sources that emit light in this wavelength range can be used.

Examples of the developing method include a liquid piling method, a dipping method, and a spray method. After exposure and development of the photocurable composition, the transparent substrate on which the necessary color pixel portion is formed is washed with water and dried. The color filter thus obtained is subjected to heat treatment (post-baking) at 100 to 280 ° C. for a predetermined time by a heating device such as a hot plate or an oven to remove volatile components in the coating film and at the same time photocuring. The unreacted photocurable compound remaining in the cured colored film of the curable composition is thermally cured to complete the color filter.

The above-described photocurable composition (also referred to as a pigment-dispersed photoresist) for forming the color filter green pixel portion is composed of the polyhalogenated metal phthalocyanine pigment of the present invention, a dispersant, a photocurable compound, and an organic compound. It can be prepared by using a solvent as an essential component and mixing them using a thermoplastic resin as necessary. When the colored resin film forming the green pixel portion requires toughness that can withstand baking performed in the actual production of a color filter, a photocurable compound is used in preparing the photocurable composition. In addition, it is essential to use this thermoplastic resin in combination. When a thermoplastic resin is used in combination, it is preferable to use an organic solvent that dissolves it.

Among the polyhalogenated metal phthalocyanine pigments of the present invention, a suitable polybromochlorozinc phthalocyanine pigment is excellent in heat resistance, so that the hue change of color before and after the thermal history (for pre-baking and post-baking) Color difference) can be reduced.

As a method for producing the photocurable composition, the polyhalogenated metal phthalocyanine pigment of the present invention, an organic solvent and a dispersant are used as essential components, and these are mixed and stirred and dispersed so as to be uniform. First, a pigment dispersion (also called a colored paste) for forming a green pixel portion of a color filter is prepared, and then a photocurable compound and, if necessary, a thermoplastic resin or a photopolymerization initiator are added thereto. A method of adding the above to the photocurable composition is generally used.

As described above, the polyhalogenated metal phthalocyanine pigment of the present invention used here is a polyhalogenated resin comprising a copolymer of methyl methacrylate and another copolymerizable ethylenically unsaturated monomer as an acrylic resin. A metal phthalocyanine pigment and, if necessary, a yellow pigment can be used in combination.

Examples of the dispersant used here include Dispersic 130, Dispersic 161, Dispersic 162, Dispersic 163, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170, Dispersic 170 Further, a leveling agent, a coupling agent, a cationic surfactant, and the like can be used together.

Examples of the organic solvent used here include aromatic solvents such as toluene, xylene and methoxybenzene, acetate solvents such as ethyl acetate and butyl acetate, propylene glycol monomethyl ether acetate and propylene glycol monoethyl ether acetate, ethoxy Propionate solvents such as ethyl propionate, alcohol solvents such as methanol and ethanol, ether solvents such as butyl cellosolve, propylene glycol monomethyl ether, diethylene glycol ethyl ether and diethylene glycol dimethyl ether, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone , Aliphatic hydrocarbon solvents such as hexane, N, N-dimethylformamide, γ-butyrolactam, N-methyl-2- Pyrrolidone, aniline, nitrogen compound-based solvent such as pyridine, .gamma.-lactone solvents butyrolactone, carbamic acid esters such as a mixture of 48:52 of methyl carbamate and ethyl carbamate acid. As the organic solvent, polar solvents such as propionate-based, alcohol-based, ether-based, ketone-based, nitrogen compound-based, and lactone-based solvents that are water-soluble are particularly preferable. When a water-soluble organic solvent is used, water can be used in combination.

Examples of the thermoplastic resin used for preparing the photocurable composition include urethane resins, acrylic resins, polyamic acid resins, polyimide resins, styrene maleic acid resins, styrene maleic anhydride resins, and the like. It is done.

Examples of the photocurable compound include 1,6-hexanediol diacrylate, ethylene glycol diacrylate, neopentyl glycol diacrylate, triethylene glycol diacrylate, bis (acryloxyethoxy) bisphenol A, 3-methylpentanediol di Multifunctional with relatively low molecular weight such as bifunctional monomer such as acrylate, trimethylol propaton triacrylate, pentaerythritol triacrylate, tris (2-hydroxyethyl) isocyanate, dipentaerythritol hexaacrylate, dipentaerythritol pentaacrylate Monofunctional, polyester acrylate, polyurethane acrylate, polyether acrylate, etc. It is.

Examples of the photopolymerization initiator include acetophenone, benzophenone, benzyldimethylketanol, benzoyl peroxide, 2-chlorothioxanthone, 1,3-bis (4′-azidobenzal) -2-propane, 1,3-bis (4 '-Azidobenzal) -2-propane-2'-sulfonic acid, 4,4'-diazidostilbene-2,2'-disulfonic acid and the like.

The polyhalogenated metal phthalocyanine pigment of the present invention is composed of 300 to 1000 parts of an organic solvent and 0 to 100 parts per 100 parts of the polyhalogenated metal phthalocyanine pigment in terms of mass using each of the materials as described above. The pigment dispersion can be obtained by stirring and dispersing the dispersant in a uniform manner. Subsequently, the total amount of the thermoplastic resin and the photocurable compound is 3 to 20 parts per part of the polyhalogenated metal phthalocyanine pigment of the present invention in this pigment dispersion, and 0.05 to 3 parts per part of the photocurable compound A photo-curable composition for forming a color filter green pixel portion can be obtained by adding a photopolymerization initiator and, if necessary, further an organic solvent, and stirring and dispersing so as to be uniform.

As the developer, a publicly known and commonly used organic solvent or alkaline aqueous solution can be used. In particular, when the photocurable composition contains a thermoplastic resin or a photocurable compound, and at least one of them has an acid value and exhibits alkali solubility, the color filter can be washed with an alkaline aqueous solution. This is effective for forming the green pixel portion.

The color filter green pixel portion prepared using the polyhalogenated metal phthalocyanine pigment of the present invention has been described in detail regarding the manufacturing method using the photolithography method among the pigment dispersion methods. A color filter may be manufactured by forming a green pixel portion by a manufacturing method such as a method, a micelle electrolysis method, or a PVED (Photovoltaic Electrodeposition) method.

The color filter uses a photocurable composition of each color obtained by using a red pigment, a blue pigment, and the polyhalogenated metal phthalocyanine pigment of the present invention, and encloses a liquid crystal material between a pair of parallel transparent electrodes. The transparent electrode is divided into discontinuous fine sections, and each of the fine sections divided in a lattice pattern by the black matrix on the transparent electrode is red (R), green (G), or blue (B). The color filter coloring pixel portions selected from these colors can be alternately provided in a pattern, or the color filter coloring pixel portions can be formed on the substrate, and then a transparent electrode can be provided.

The polyhalogenated metal phthalocyanine pigment of the present invention is excellent in the storage stability of the pigment dispersion for the color filter due to the dispersibility and dispersion stability of the pigment, and further in the contrast of the coating film of the color filter green pixel portion. In addition to the above-mentioned color filter applications, paint compositions, plastics (resin molded products), printing inks, rubber, leather, textile printing, electrostatic charge image developing toners, inkjet recording It can also be used for coloring applications such as industrial inks and thermal transfer inks.

Hereinafter, the present invention will be described in detail with reference to production examples, examples, and comparative examples. The present invention is not limited to these examples. Unless otherwise specified, both “part” and “%” are based on mass.

First, zinc phthalocyanine was produced by a known method using phthalodinitrile, ammonia, and zinc chloride as raw materials. This 1-chloronaphthalene solution had light absorption at 750 to 850 nm. Halogenation was performed by mixing 3.1 parts of sulfuryl chloride, 3.7 parts of anhydrous aluminum chloride and 0.5 parts of sodium chloride at 40 ° C., and adding 1 part of the prepared zinc phthalocyanine. Further, 4.4 parts of bromine was added dropwise and reacted for 17 hours up to 130 ° C., and then the reaction mixture was poured into water to precipitate a polybromochlorozinc phthalocyanine crude pigment. This aqueous slurry was filtered, washed with hot water at 60 ° C., washed with 1% caustic soda at 70 ° C. for 1 hour, and confirmed to have a specific conductivity of 0.50 ms / cm or less and then dried at 90 ° C. 3.0 parts of purified crude polybromochlorozinc phthalocyanine pigment was obtained. The analysis result of the crude pigment by mass spectrometry is the average composition ZnPcBr ₁₄ Cl ₁ H (in the above general formula 1, X _{1 to} X ₁₆ are chlorine atom, bromine atom and hydrogen atom, 14 substituted bromine atoms, chlorine It corresponds to one atom and one hydrogen atom.). The TBPI content in the crude pigment was calculated according to the following method and is shown in Table 1.

(Calculation of TBPI content in crude pigment) First, tetrabromophthalimide was purchased with a reagent and dissolved in methanol for high performance liquid chromatography (manufactured by Wako Pure Chemical Industries, Ltd.), and then a calibration curve was prepared by high performance liquid chromatography. To do. Thereafter, 1.00 g of the crude pigment is accurately weighed with a precision balance, immersed in 25 ml of the above methanol and dispersed for 30 minutes with an ultrasonic vibration device, and then the filtrate is separated with 0.45 μm filter paper. The filtrate is introduced into high performance liquid chromatography, and the tetrabromophthalimide content (in terms of mass) in the crude pigment is calculated from the detected peak area. For measurement, a Waters 2690 separations module was used, the eluent was ion-exchanged water and methanol, and the measurement wavelength was 254 nm.

The operation of “washing with hot water at 60 ° C. and washing with 1%, 70 ° C. caustic soda for 1 hour” was performed on the filter residue obtained by filtering the aqueous slurry. The procedure was the same as in Example 1 except that the operation was changed to “Break and wash for 1 hour” and dried at 90 ° C. to obtain 2.9 parts of purified polybromochlorozinc phthalocyanine crude pigment. The analysis result of the crude pigment by mass spectrometry was the same as in Example 1. The TBPI content in the crude pigment was calculated in the same manner as in Example 1 and shown in Table 1.

(Comparative example 1) About the filter residue obtained by filtering the aqueous slurry, the operation of “washing with hot water at 60 ° C. and washing with 1% caustic soda at 70 ° C. for 1 hour” Then, the same operation as in Example 1 was performed except that the operation was carried out three times for 1 hour with caustic soda at 5% and 70 ° C., followed by drying at 90 ° C. and purification of 2.8 parts. A crude polybromochlorozinc phthalocyanine pigment was obtained. The analysis result of the crude pigment by mass spectrometry was the same as in Example 1. The TBPI content in the crude pigment was calculated in the same manner as in Example 1 and shown in Table 1.

(Comparative Example 2) The operation of “washing with hot water at 60 ° C. and washing with 1% caustic soda for 1 hour” with respect to the filter residue obtained by filtering the aqueous slurry is carried out with “washing with hot water at 60 ° C.” The procedure was the same as in Example 1 except that the procedure was changed to “Operation”, followed by drying at 90 ° C. to obtain 3.0 parts of a purified polybromochlorozinc phthalocyanine crude pigment. The analysis result of the crude pigment by mass spectrometry was the same as in Example 1. The TBPI content in the crude pigment was calculated in the same manner as in Example 1 and shown in Table 1.

150 parts of the crude polybromochlorozinc phthalocyanine pigment of Example 1, 3000 parts of crushed sodium chloride, and 654 parts of diethylene glycol were charged into a double-arm kneader having a capacity of 8 L, and kneaded and ground at 90 ° C. for 4 hours. After the kneading and grinding, the kneader cake (kneaded mixture) is put into 60 L of water and stirred at 60 ° C. for 1 hour, and the aqueous slurry is filtered. Subsequently, the filtrate was washed with water to such an extent that the specific conductivity of the filtrate was not inferior to that of purified water, thereby completely removing the water-soluble inorganic salt and the organic solvent. The pigment cake thus obtained was dried overnight at 80-120 ° C. in a box dryer, pulverized with a juicer mixer, and the average primary particle diameter 70 nm and aspect ratio 2 of polybromochlorozinc phthalocyanine pigment (a) Got. TBPI was not mixed into the system at each step.

Instead of the polybromochlorozinc phthalocyanine crude pigment of Example 1, the same operation as in Example 3 was performed except that the same amount of the crude pigment of Example 2 was used. 2 of polybromochlorozinc phthalocyanine pigment (b) was obtained.

(Comparative example 3) It replaced with the polybromochloro zinc zinc phthalocyanine crude pigment of Example 1, and performed operation similar to Example 4 except having used the same amount of the same crude pigment of Comparative Example 1, and average particle | grains of primary particles A polybromochlorozinc phthalocyanine pigment (c) having a diameter of 70 nm and an aspect ratio of 2 was obtained.

(Comparative Example 4) Instead of the polybromochlorozinc phthalocyanine crude pigment of Example 1, the same operation as in Example 4 was carried out except that the same amount of the crude pigment of Comparative Example 2 was used. A polybromochlorozinc phthalocyanine pigment (d) having a diameter of 70 nm and an aspect ratio of 2 was obtained.

Using the polybromochlorozinc phthalocyanine pigment (a) obtained in Example 3 as a green pigment, a color filter green pixel portion was manufactured by a photolithography method. As a method for producing the color filter green pixel portion, 10 parts of polybromochlorozinc phthalocyanine pigment (a), 2.5 parts of N, N′-dimethylformamide (organic solvent), Dispersic 161 (dispersant manufactured by BYK Chemie) 6 .78 parts, Euker ester EEP (organic solvent manufactured by Union Carbide) 80.80 parts was added with 0.5 mmφ Sepul beads and dispersed with a paint conditioner (manufactured by Toyo Seiki Co., Ltd.) for 1 hour, and pigment dispersion (colored paste) ) 75.00 parts of this pigment dispersion and Aronix M7100 (polyester acrylate resin, manufactured by Toa Gosei Chemical Co., Ltd., corresponding to a photocurable compound) 5.50 parts, KAYARAD DPHA (dipentaerylate hexaacrylate, 5.00 parts by Nippon Kayaku Co., Ltd., corresponding to a photocurable compound.) 5.00 parts, KAYACURE BP-100 (benzophenone, Nippon Kayaku Co., Ltd., corresponding to a photopolymerization initiator) 1.00 parts. 13.5 parts of Euker ester EFP was stirred with a dispersion stirrer to obtain a photocurable composition for forming a color filter green pixel part. This photocurable composition was applied to 1 mm thick glass so as to have a dry film thickness of 1 μm.

Subsequently, after performing pattern exposure with ultraviolet rays through a photomask, the color filter green pixel portion was manufactured by washing the unexposed portion with an organic solvent.

Similar to Example 3, except that the polybromochlorozinc phthalocyanine pigment (b) obtained in Example 4 was used as a green pigment instead of the polybromochlorozinc phthalocyanine pigment (a) obtained in Example 3. The color filter green pixel portion was manufactured by the above operation.

(Comparative Example 5) Instead of the polybromochlorozinc phthalocyanine pigment (a) obtained in Example 3, the polybromochlorozinc phthalocyanine pigment (c) obtained in Comparative Example 3 was used as a green pigment. A color filter green pixel portion was manufactured in the same manner as in Example 3.

(Comparative Example 6) Instead of the polybromochlorozinc phthalocyanine pigment (a) obtained in Example 3, the polybromochlorozinc phthalocyanine pigment (d) obtained in Comparative Example 4 was used as a green pigment. A color filter green pixel portion was manufactured in the same manner as in Example 3.

About the color filter green pixel part obtained by these Examples 5-6 and Comparative Examples 5-6, the contrast of the coating film was measured according to the following method, and the result was shown in Table 1. (Measurement of the contrast of the coating film of the color filter green pixel part) The contrast of the coating film is set by placing the color filter green pixel part between two polarizing plates, a light source on one side, and a CCD camera on the opposite side. Then, the transparency was measured. The ratio of transparency (transmitted light intensity) between when the polarization axis was parallel and when it was perpendicular was calculated and evaluated as contrast.

Table 1

As is apparent from the results in Table 1, the color filter green pixel portions of Examples 5 and 6 obtained from the pigment having the specific TBPI content were similarly obtained from the pigment having the TBPI content outside the range. It can be seen that the contrast of the coating film is excellent as compared with the color filter green pixel portions of Comparative Examples 5 and 6. As shown in Table 1, the effect of TBPI content on coating film contrast was very significant.

The polybromochlorozinc phthalocyanine pigment (a) obtained in Example 3 was the same particle size as that of C.I. I. A green pigment composition was prepared by toning with pigment yellow 138 (quinophthalone pigment). Similarly, C.I. having the same particle size as that of the pigment (a) is used. I. Pigment Red 254 (diketopyrrolopyrrole pigment) was toned with the same pigment (a) to prepare a red pigment composition. Similarly, C.I. having the same particle size as that of the pigment (a) is used. I. Pigment Blue 15: 6 (ε-type copper phthalocyanine pigment) was added to C.I. I. A blue pigment composition was prepared by toning with Pigment Violet 23 (dioxazine pigment). Subsequently, according to Example 5, each photocurable composition of green, red, and blue was produced, and the green pixel part (G), the red pixel part (R), and the blue pixel part (B) were formed. As described above, a color filter was manufactured from the obtained RGB color pixel portions. As a result, this color filter is compared to a color filter produced in the same manner using each of the green, red and blue photocurable compositions prepared using pigments whose TBPI content is outside the specified range. The coating film contrast was extremely excellent.

From the above, the polyhalogenated metal phthalocyanine pigment of the present invention having a tetrabromophthalimide content of 0.10% to 1.50% and an average primary particle size of 10 nm to 100 nm is produced in the color filter green pixel portion. Suitable for.

Claims (5)

A polyhalogenated metal phthalocyanine crude pigment for a color filter green pixel portion having a tetrabromophthalimide content of 0.10 to 1.50%. A polyhalogenated metal phthalocyanine pigment for a color filter green pixel portion having a tetrabromophthalimide content of 0.10 to 1.50% and an average primary particle diameter of 10 to 100 nm. The pigment according to claim 2, which has a tetrabromophthalimide content of 0.10 to 1.00%. The polyhalogenated metal phthalocyanine pigment according to claim 2 or 3, wherein the polyhalogenated metal phthalocyanine pigment is a polybromochlorozinc phthalocyanine pigment. A color filter comprising the green pixel portion containing the polyhalogenated metal phthalocyanine pigment according to any one of claims 2 to 4.