Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Processes of preparing a desired or intentional composition...
Reexamination Certificate
2001-12-19
2004-04-06
Sanders, Kriellion A. (Department: 1714)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Processes of preparing a desired or intentional composition...
C523S106000
Reexamination Certificate
active
06716897
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-390822, filed Dec. 22, 2000, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a colored composition for color filter used in a color liquid crystal display device or a solid state image sensor, and also to a color filter employing this colored composition.
2. Description of the Related Art
A color filter is generally provided, on the surface of a transparent substrate such as a glass substrate, with at least two fine stripe-shaped filter segments differing in hue from each other. These filter segments are disposed parallel or intersected with each other, or regularly arrayed vertically and horizontally. Each filter segment is fine in width, i.e., in the range of several micrometers to several hundreds micrometers, and is arrayed regularly for each hue.
On a color filter used in a color liquid crystal display device, transparent electrodes for actuating the liquid crystal are formed usually by means of vapor deposition or sputtering. Further, an alignment film for aligning the liquid crystal in a predetermined direction is formed over the transparent electrodes. In order to make the best use of the performances of these transparent electrodes and alignment film, the deposition of them is required to be performed at a high temperature of usually 200° C. or more, preferably 230° C. or more.
Therefore, the manufacture of the color filter is mainly performed at present by a method called a pigment dispersion method wherein pigments, which are excellent in light resistance and heat resistance, are employed as a colorant. Specifically, a color filter is now manufactured mainly by the following two methods.
According to a first method, a dispersion of pigment of a first color in a solution of a photosensitive transparent resin is coated on the surface of a transparent substrate such as a glass substrate. The coated layer is dried to remove the solvent, and then subjected to a patterning exposure, followed by a developing process to remove the unexposed portions, thus forming a pattern of the first color. Subsequently, a processing such as a heat treatment is applied to the first color pattern, if required. Thereafter, the procedures similar to those described above are repeated successively for all of the remaining filter colors. In this way, a desired color filter is produced.
According to a second method, a dispersion of pigment of a first color in a solution of transparent resin is coated on the surface of transparent substrate such as glass substrate. The coated layer is dried to remove the solvent. A resist such as a positive resist is coated on the surface of the coated layer, and subjected to a patterning exposure. Then, the resist layer is subjected to a developing process to form a resist pattern, which is used as an etching resist in the subsequent process wherein those portions of the coated layer which are not covered by the resist pattern are removed with an etching solution. Thereafter, the resist pattern is removed to form a pattern of the first color. Subsequently, a processing such as a heat treatment is applied to the first color pattern, if required. Thereafter, the procedures similar to those described above are repeated successively for all of the remaining filter colors. In this way, a desired color filter is produced. In this case, the developing of the resist and the etching of the coated layer may be performed simultaneously.
In the manufacture of green filter according to the aforementioned methods, a colored composition containing halogenated copper phthalocyanine green pigment has been conventionally employed. 16 halogen atoms can be introduced into the phthalocyanine ring, and C.I. Pigment Green 7, in which only chlorine atoms are introduced as halogen atoms into the copper phthalocyanine, C.I. Pigment Green 36, in which chlorine and bromine atoms are introduced into the copper phthalocyanine, are known. Generally, the higher the content of bromine introduced into copper phthalocyanine is, the higher the tendency that the visible light-transmitting wavelength region is shifted toward a longer wavelength side. The brightness (Y value) among three stimulus values of XYZ color specification system can be enhanced when the light-transmitting wavelength region is shifted toward a longer wavelength side as far as the green filter of color filter is concerned. Thus, C.I. Pigment Green 36 is generally employed for a green color filter.
However, there is a limitation in the quantity of bromine (i.e., at most 16 bromine atoms) that can be introduced into copper phthalocyanine pigment. Nonetheless, there is a strong demand for a green colored composition that can provide a green filter whose light-transmitting wavelength region is further shifted toward a longer wavelength side to further improving the brightness.
Therefore, an object of the present invention is to provide a colored composition for color filter, which is capable of providing a green filter exhibiting an improved brightness, and a color filter.
BRIEF SUMMARY OF THE INVENTION
The present inventors have made intensive studies in an attempt to achieve the aforementioned object. As a result, they have found that a combination of a halogenated copper phthalocyanine pigment and a halogenated metallophthalocyanine pigment having, as a central metal, a specified metal other than copper at a specified ratio can shift the light-transmitting wavelength region toward a longer wavelength side, thus making it possible to obtain a green filter exhibiting a further increased brightness.
Thus, the present invention provides a green colored composition for color filter, which comprises a colorant carrier comprising a transparent resin, a precursor of a transparent resin or a mixture thereof; and a green colorant dispersed in the colorant carrier and comprising at least one first halogenated metallophthalocyanine pigment having copper as a central metal, and at least one second halogenated metallophthalocyanine pigment having, as a central metal, a metal selected from the group consisting of Mg, Al, Si, Ti, V, Mn, Fe, Co, Ni, Zn, Ge and Sn; wherein the content of the second halogenated metallophthalocyanine pigment is within a range of 1 to 80 mol % based on a total amount of the green colorant.
In the colored composition of the present invention, the first halogenated metallophthalocyanine pigment preferably contains 8 to 16 bromine atoms per molecule thereof.
Further, in the colored composition of the present invention, the second halogenated metallophthalocyanine pigment preferably contains 8 to 16 bromine atoms per molecule thereof.
According to a second aspect of the invention, there is provided a color filter comprising at least one red filter segment, at least one blue filter segment, and at least one green filter segment, wherein at least one green filter segment is prepared from a colored composition of the present invention.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
DETAILED DESCRIPTION OF THE INVENTION
The colored composition according to the present invention contains a colorant carrier formed of a transparent resin, a precursor of a transparent resin or a mixture thereof, and a green colorant dispersed in the colorant carrier. The green colorant comprises a first halogenated metallophthalocyanine pigment having copper as a central metal, and a second halogenated metallophthalocyanine pigment having, as a central metal, a specified metal other than copper. The colorant carrier provides a resinous binder in a finished green filter segm
Fujita Ken-ichi
Hirasawa Yuji
Kodama Yukio
Okutsu Satoshi
Sawamura Masashi
Nixon & Vanderhye P.C.
Sanders Kriellion A.
Toyo Ink Mfg. Co. Ltd.
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