Title of Invention	A METHOD FOR MANUFACTURING A DISAZO PIGMENT COMPOSITION
Abstract	A method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, the coupler components are not substantially precipitated, and the tetrazo component reacts immediately. CH3COCH2CONH - Z ... General Formula (I) [wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom]. CH3COCH2CONH - Y ... General Formula (II) [wherein, Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

Title of Invention

A METHOD FOR MANUFACTURING A DISAZO PIGMENT COMPOSITION

Abstract

A method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, the coupler components are not substantially precipitated, and the tetrazo component reacts immediately. CH3COCH2CONH - Z ... General Formula (I) [wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom]. CH3COCH2CONH - Y ... General Formula (II) [wherein, Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

Full Text	1A TECHNICAL FIELD OF THE INVENTION The present invention relates to a method for manufacturing a disazo pigment composition. More specifically the present invention relates to (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exihibits a superior transparency and flow ability. This application is based on the patent application No. Hei 10-11503 3, filed in Japan, the contents of which are incorporated herein by reference. BACKGROUND ART As examples of conventional methods for improving transparency and flow ability of printing inks containing disazo pigments, Japanese Patent Application, Second Publication No. Sho 45-11026 discloses a method for mixing sulfonic acid compounds into disazo pigments; Japanese Patent Application, Second Publication No. Sho. 55-49087 discloses a method for using a disazo pigment formed by using a mixture of non-polar coupling components and polar coupling components having carboxyl groups and/or sulfo groups as coupling components; and Japanese Patent Application, First Publication No. Sho 63-72762 and Japanese Patent Application, First Publication No. Sho 63-178169 respectively disclose a method of using a disazo pigment composition containing asymmetric disazo compounds which are formed from polar coupling components and non-polar coupling components, -2- respectively. Among these disclosures, it is known that a disazo pigment obtained according to the method disclosed in Japanese Patent Application, Second Publication No. Sho. 55-49087 is more effective in improving the transparency of printing inks, and that a disazo pigment composition disclosed in Japanese Patent Application, First Publication No. Sho 63-178169 is more effective in improving the flow ability of printing inks. In addition, as a method for improving the transparency, WO97/31067 discloses a method for coupling non-polar coupling components and tetrazo component of the benzidines. However, the extent of improvement in the transparency according to WO97/31067 is remarkably small, and Furthermore, no suggestions regarding the flow ability were mentioned. With regard to methods for manufacturing -printing inks, there exist a manufacturing method for dispersing wet pigments by means of using a kneader; and a manufacturing method for dispersing powder pigments by means of using a triple roll or beads mill. The choice of the manufacturing method is based mainly on the productivity and demands for the inks. There are several determining factors for the quality required for printing inks; among these, however, it is most important to choose a pigment that is appropriate for the intended use, as well as for the manufacturing method. In the printing industry, printing inks exhibiting a high transparency are in great demand for their role in improving the clearness of the prints. Additionally, in the printing industry, from the viewpoint of increased productivity, the printing speed is undergoing remarkable improvements. Currently, a printing, machine capable of printing at a speed of 4 meter per second enjoys widespread use as the industry .standard, however, a printing machine capable of printing 15 meter per second has been already developed. In accordance with this increasing printing speed, flow abilities greater than those obtained to date are highly desired for the printing inks. 3 Conventionally, as a method for effectively improving the transparency, Japanese Patent Application, Second Publication No. Sho: 55-49087 is known. The method disclosed in Japanese Patent Application, Second Publication No. Sho, 55-49087 provides for the synthesis of a) a disazo pigment (represented by the following general formula A), which comprises a non-polar coupling component (represented by the following general formula 1) and a non-polar coupling component (represented by the following general formula I); and b) an asymmetric disazo compound (represented by the following general formula B) comprising a polar coupling component (represented by the following general formula II) and a non-polar coupling component (represented by the following general formula I); and (c) a symmetric disazo compound (represented by the following general formula C) comprising a polar coupling component (represented by the following general formula II) and a polar coupling component (represented by the following general formula II), in,the same reaction vessel. The asymmetric disazo compound (represented by the following general formula B) is known for its effects in improving the transparency and flow ability of printing inks. However, although the method disclosed in Japanese Patent Application, Second Publication No. Sho. 55-49087 produces an asymmetric disazo compound (represented by the following general formula B) effective in improving the transparency, it also results in the large production of a symmetric disazo compound (represented by the following general formula C), which deteriorates the transparency and flow ability. Therefore, this method has failed to provide the necessary transparency desired by the present printing industry. Additionally, if the speed of dissolving the nompolar coupler component (represented by the following general formula I) into an acidic solution varies from that of the polar coupler component (expresses by the following general formula II), it is impossible to adsorb the asymmetric disazo compound (represented by the following general formula B, which is effective in improving the transparency and flow ability, uniformly to the disazo pigment 4 (represented by the following general formula A), or introduce the asymmetric disazo compound into the crystalline structure. As a result, it becomes impossible to provide the necessary transparency demanded by the present printing industry. In other words, when the speed of dissolving the polar coupler component (represented by the following general formula II) into an acidic solution is faster than the speed of dissolving the non-polar coupler component (represented by the following general formula I) into an acidic solution, the asymmetric disazo compound (represented by the following general formula B) and the symmetric disazo compound (represented by the following general formula C) are preferentially produced at the initial stage of the coupling reaction, and in the middle to later stages of the coupling reaction, only the disazo pigment (represented by the following general formula A) is produced. Thus, it is impossible to provide the transparency required by the present printing industry. In contrast, when the speed of dissolving the polar coupler component (represented by the following general formula II) into an acidic solution is slower than the speed of dissolving the non-polar coupler component (represented by general formula I) into an acidic solution, only the disazo pigment (represented by the following general formula A) is produced from the initial to middle stages of the coupling reaction, with the asymmetric disazo compound (represented by the following general formula B) and the symmetric disazo compound (represented by the following general formula C) beingpreferentially produced during the later stage of the coupling reaction. Thus, in a similar manner, it is impossible to provide the transparency required by the present printing industry. As a result of reasons, similar to the aforementioned, the method disclosed in Japanese Patent Application, Second Publication No. Sho 55-49087 failed to provide the flow ability required by the present printing industry. 5 CH3COCH2CONH - Z ... General Formula (I) [wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom]. CH3COCH2CONH - Y ... General Formula (II) [wherein, Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom, and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof]. [wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from" the group consisting of a methyl group, methoxy group, and chlorine atom]. 6 [wherein, Z1 represents a phenyl group, which may .contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof]. [wherein, Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof). 7 Additionally, as a conventional technology for effectively improving the flow ability, the method disclosed in Japanese Patent Application, First Publication No. Sho. 63-178169 is known. The method disclosed in Japanese Patent Application, First Publication No. Sho. 63-178169 relates to a disazo pigment composition, which is formed by means of synthesizing an asymmetric disazo compound (represented by general formula B) comprising a polar coupling component and a non-polar coupling component, and adding the asymmetric disazo compound (represented by general formula B) to a separately synthesized, disazo pigment (represented by general formula A), comprising a non-polar coupling component and a non-polar coupling component. However, due to collision of the particles resulting from the stirring during the process of synthesis, or forces imposed during the processes of filtration, drying, and grinding, particles of the disazo pigment, and the asymmetric disazo compound become aggregated, which makes it difficult to adsorb the asymmetric disazo compound to the primary particle surface of the disazo pigment, thereby resulting in a failure to provide tfre flow ability required by the present printing industry. Due to reasons similar to the aforementioned, the above- method is not able provide the transparency required by the present printing industry. Herein, although an attempt was made at increasing the blending amount of the asymmetric disazo compound (represented by general formula B), a deterioration in the tinting strength occurred, such that the above method was not able to provide a disazo pigment suitable for practical use. In addition, as a conventional technology for improving the transparency, the method disclosed in W097/3106.7-is also known. The method disclosed in W097/31067 relates to a method for manufacturing a disazo pigment, which is formed by means of coupling the tetrazo component of the benzidine in an acidic solution. This method effectively reduces the 8 aromatic amines, which are by-products of the reaction, by means of improving the coupling reaction rate, resulting in an easier removal of unreacted coupling components. Additionally, it is disclosed that when used as a coloring agent, the resultant pigment results in an improvement in the transparency, the tinting strength, and glossiness thereof. The method disclosed in WO97/31067 shows a slight improvement in the transparency, when compared with the conventional method for manufacturing a disazo pigment, in which coupling with the tetrazo component of the benzidine is performed in an acidic solution after precipitating the non-polar coupling components. However, the mechanism for,improving the transparency in the aforementioned method lies in the removal of the unreacted, non-polar coupling components, which have a lower light transmittance and lower transparency (i.e., higher hiding power), compared to those of a disazo pigment. Thus, the extent of the improvement in the transparency is remarkably small, and the method has failed to provide the transparency required by the present printing industry. Moreover, the method disclosed in WO97/31067 makes no disclosure relating to the flow ability, nor provides any effects of improving the flow ability. Furthermore, according to the aforementioned conventional method which can produce a disazo pigment derivative (represented by general formula B) comprising an asymmetric disazo compound, and a disazo pigment (represented by general formula A) simultaneously, the maximum weight ratio of the asymmetric disazo compound (represented by general formula B) to the symmetric disazo compound (represented by general formula C) is limited to 90:10. Therefore, this method is still unsatisfactory from the standpoint of a variety of other properties. DISCLOSURE OF THE INVENTION 9 The object of the present invention is to provide (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exhibits a superior transparency and flow ability. In addition, another object of the present invention relates to a method for improving the properties of the pigment. The inventors of the present invention have achieved the present invention as a result of intense research to develop (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exhibits a superior transparency and flow ability. In this manner, the inventors have found that the following means are effective in achieving the aforementioned objects. In other words, the present invention provides the following inventions. A method for manufacturing a disazo pigment composition, wherein a disazo pigment and a disazo compound other than said disazo pigment, which can improve at leasyone property among the transparency and flow ability of the pigment, can be produced simultaneously, by means of performing a coupling reaction of an aqueous coupler solution, containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately. 10 Accordingly the present invention provides a method for manufacturing a disazo pigment composition comprising, as essential components, a dtsazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, wherein 1) at least a portion of said asymmetric disazo compound represented bv general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof; 2) said disazo pigment composition comprises 98.0 to 72,3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and 3) an amount of said asymmetric disazo compound represented bv general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight wherein Z1 represents a phenyl group, which may contain 1 .to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain .1 to 4 identicaj or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or 10A potassium: said method comprising the steps of; simultaneously producing the disazo pigment represented by general formula A, and the asymmetric disazo compound represented by general formula 3, by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (1) represented by general formula (1) and a polar coupler component (II) represented by general formula (II) and an aqueous, tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately CH3COCH2CONH - Z ... General Formula (1) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. .. The present invention also provides a method for manufacturings disazo pigment composition comprising, as essential components, a disazo pigment represented by general formula A, an asymmetric disazo compound represented by general formula B, and a symmetric disazo compound represented by general formula C, wherein; 1) at least a portion of said asymmetric disazo compound represented by general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof; 2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of the disazo compounds other than said disazo pigment; and 3) the weight ratio of said asymmetric disazo compound represented by general formula B'to said symmetric disazo compound represented by general formula C is less than 100/0 parts by weight and at least 93/7 parts by weight when the total weight of the disazo compounds other than said disazo pigment is 100 parts by weight 10B wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,_and said phenyl group as Z\contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium wherein Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1-, to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium: 10C said method comprising the steps of: simultaneously producing the disazo pigment represented by general formula A, the asymmetric disazo compound represented by general formula B, and the symmetric disazo compound represented by general formula C by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component-(I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately, CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH- Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. The present invention also provides a method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound'represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution Containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, said coupler components are not substantially precipitated, and the tetrazo component reacts immediately 10D wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein the carboxyl group and the sulfo group form alkali metal salts with sodium or potassium CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH - Y '...General Formula(II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof. The present invention also provides a method for improving transparency and flow ability of a disazo pigment represented by general formula A comprising the steps of: 1) uniformly adsorbing at least a portion of an asymmetric disazo compound represented by general formula B to the primary particles of said disazo pigment represented by general formula A, or alternatively comprising at least a portion of said asymmetric disazo compound in the crystalline structure thereof, such that 2) a disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigrrient represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and 11 3) an amount of said asymmetric disazo compound represented by general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group.consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atoma and said phenyl group as Z2contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. 11A Furthermore, an object of the present invention are to provide the following disazo pigment compositions and printing inks. (1) A disazo pigment composition, which is formed by means of continuously pouring (or injecting) an aqueous coupler solution, containing a non-polar coupler component (I) represented by the above general formula (I) and a polar coupler component (II) represented by the above general formula (II), and an aqueous tetrazo solution 12 containing a tetrazo component of a benzidine, into an acidic solution in a batch stirring tank, such that the ratio of the total molar supply speed of the non-polar coupler component (I) and the polar coupler component (II) to the molar supply speed of the tetrazo component is in the range between 200:80 and 200:99, to induce a coupling reaction. (2) A disazo pigment composition according to the aforementioned (1), wherein the ratio of the total molar supply speed of the non-polar coupler component (I) and the polar coupler component (II) to the molar supply speed of the tetrazo component is in the range between 200:90 and 200:99. (3) A disazo pigment composition according to the aforementioned (1) or (2), wherein after continuously pouring (or injecting) an aqueous coupler solution, containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine, into an acidic solution in a batch stirring tank, only the aqueous tetrazo solution is additionally poured (or injected) therein. (4) A disazo pigment composition according to one of the aforementioned (1), (2), or (3), wherein a buffer solution is present in the acidic solution in the aforementioned batch stirring tank. (5) A disazo pigment composition according to one of the,aforementioned (1.), (2), (3), or (4), wherein an aqueous coupler solution, in which the total (sum) concentration of/the non-polar coupler component (I) and the polar coupler component (II) is in the range of 13 0.1 to 1 mol/liter; and an aqueous tetrazo solution, the concentration of which is in the range of 0.05 to 0.8 mol/liter, are used. (6) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), or (5), wherein the ratio of the amount of the acidic solution to the amount of the aqueous coupler solution and the aqueous tetrazo solution poured (or injected) per minute is in the range of 1000:1 to 1000:50. (7) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), or (6), wherein said non-polar coupler component (I) is at least one compound selected from the group consisting of acetoacetanilide, acetoacet-o-toluidide, and acetoacet-m-xylidide. (8) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), or (7), wherein said polar coupler component (II) is at least one compound selected from the group consisting of 4-acetoacetylaminobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, and 5-acetoacetylamino-2-hydroxy benzoic acid. (9) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), (7), or (8), wherein said aqueous coupler solution is an alkali solution, and said aqueous tetrazo solution is a hydrochloric acid solution. (10) A printing ink, which contains a disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), (7), (8), or (9). 14 BEST MODE OF CARRYING OUT THE INVENTION The method for manufacturing a disazo pigment composition according to the present invention relates to a method for manufacturing a disazo pigment composition, wherein an aqueous coupler solution containing a coupler component (I) and a coupler component (II), arid an aqueous tetrazo solution containing a tetrazo component of abenzidine, are poured into an acidic solution, to induce a coupling reaction. Herein, a coupling reaction is performed by means of pouring the coupler components into an acidic solution, such that, in the reaction system, none of the coupler components are precipitated, and the tetrazo component reacts immediately. As a. result, as described in greater detail below, at least a portion of the asymmetric disazo compound can be adsorbed uniformly to the primary particles of the aforementioned disazo pigment, or alternatively included in the crystalline structure thereof. In the present invention, conventionally known and used coupler components may be used as the coupler component (I) and/or the coupler component (II). The pouring method is not particularly limited, however, pouring is continuously performed under normal circumstance. These aspect are described in detail below. In other, words, according to the method of the present invention, a disazo pigment, which comprises a disazo pigment (represented by general formula A), comprising a non-polar coupling component and a non-polar coupling component; an asymmetric disazo compound (represented by general formula B), comprising a polar coupling component and a non-polar coupling component; and a symmetric disazo compound (represented by general formula C) comprising two polar coupling components, is simultaneously provided, while manufacturing a disazo compound composition with a higher-than-conventional content ratio of the asymmetric disazo compound comprising a polar coupling component and a non-polar 15 coupling component. [wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom]. [wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected, from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to_4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof]. 16 [wherein, Z2 represents a phenyl group which may contain 1 to 4 identical or different substituenf group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof]. The asymmetric disazo compound (above general formula B) is known to improve the transparency and flow ability of the printing ink. According to the present invention, by means of synthesizing, simultaneously, this asymmetric disazo compound with a disazo pigment (represented by general formula A), it is possible to uniformly adsorb the asymmetric disazo compqund, which is in a non-aggregate state, to the surface of the primary particles of the disazo, pigment, which is similarly in a non-aggregate state; or alternatively to, form a mixed,crystal comprising the disazo pigment and the asymmetric disazo compound. In this manner, it is possible to introduce a polar group onto the surface of the disazo pigment, and thus to obtain a disazo pigment composition which can provide the printing ink with a superior transparency and flow ability. The effects of the present invention are manifested synergistically in the ability to include a greater (more than the conventional) amount of the asymmetric component, (i.e., a pigment derivative component) in the total disazo pigment composition comprising the 17 disazo pigment derivative, which corresponds to the asymmetric disazo compound, and the disazo pigment, which corresponds to the symmetric disazo compound; and the ability to produce the aforementioned disazo pigment and disazo pigment derivative almost simultaneously, when considering the change of the produced components during the reaction. In other words, even in the situation that both the disazo pigment and the disazo pigment derivative are finally produced, but either said pigment or said derivative is preferentially produced during the reaction, the resultant effects are unsatisfactory, even if the amount of disazo pigment contained is the same as that in the simultaneous synthesis situation. These effects of the invention meet the criteria of simultaneous synthesis. According to the conventional, method for manufacturing a disazo pigment composition, after the coupler component (I), or both the coupler component (I) and the coupler component (II), are dispersed in an acidic solution, an aqueous tetrazo solution containing a tetrazo component of a benzidine is added thereto. Both the coupler component (I) and the coupler component (II) are less soluble and dissolve at a slow rate in an acidic solution. On the other hand, the aqueous tetrazo solution containing a tetrazo component of a benzidine reacts extremely well in the aforementioned environment. Consequently, the rate determination of the reaction between the coupler component (I) and/or the coupler component (II), and the aqueous tetrazo solution, containing a tetrazo component of a benzidine, occurs during the course of dissolving the coupler component (I) and/or the coupler component (II), in an acidic solution. If the speed of dissolving the.coupler component (I) in an acidic solution differs from that of the coupler component (II), a smaller amount of the asymmetric disazo compound (represented by general formula B), which provides the effects of improving transparency and flow ability, and a greater amount of the symmetric disazo compound (represented by 18 general formula C), which does not contribute towards improving transparency and flow ability, are produced. Thus, it becomes difficult to provide the superior transparency and flow ability, required by the present printing industry. When comparing the present invention and WO97/31067, the foremost point of difference in the technical structures of the two disclosures lies in that only a non-polar couplercomponenrts used in WO97/31067, while both a non-polar coupler component and polar coupler component are used in the present invention. Accordingly, the molar ratio of the total amount of the coupler components to the amount of the tetrazo component may be selected from within the range conventionally known. For example, the molar ratio of the total amount of the coupler components to the amount of the tetrazo component is in the range between 2:0.8 to 2:0.99. However, the molar supply speed can be expressed more precisely using this molar ratio. According to the present invention, the total molar supply speed of the coupler component (I) and coupler component (II) is preferably faster than the molar supply speed of the tetrazo component; in this manner, a total molar supply speed of the former equaling 2.0 to 2.5 times the molar supply speed of the tetrazo component may be selectively obtained. In oilier words, since the present invention provides a disazo pigment composition, the total number of moles of the coupler component (I) and the coupler component (II) supplied is preferably greater than the number of moles of the tetrazo component that are supplied, such that two azo bonds are formed (i.e., to form a 'disazo' compound), wherein the number of moles .of the former is 2.0 to 2.5 times greater than the number of moles of the latter. In particular, the number, of moles of the former is 2.0 to 2.5 times greater than the number of moles of the latter, optimally during,,or at the point of pouring the aqueous tetrazo solution. A preferred method for manufacturing a.disazo pigment composition according to the 19 present invention comprises performing a coupling reaction by means of continuously pouring an aqueous coupler solution containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, into an acidic solution, such that the ratio of the total molar supply speed of the coupler component (I) and the coupler component (II) to the molar supply speed of the tetrazo component ranges between 200:80 and 200:99. In other words, since an aqueous coupler solution concurrently containing a coupler component (I) and a coupler component (II) is used and supplied continuously into an acidic solution, the reaction with the aforementioned aqueous tetrazo solution containing a tetrazo component of a benzidine proceeds, during which time, the aforementioned coupler component (I) and coupler component (II) are either not precipitated, or precipitated in an extremely small amount. Accordingly, a larger amount of the asymmetric disazo compound (represented by general formuja B), which provides the advantageous effects of improving transparency and flow ability, is produced, while little to none of the symmetric disazo compound (represented by general formula C), which does not contribute towards improving the transparency and flow ability, is produced. Thus, it is possible to provide the necessary transparency and flow ability, required by the present printing industry. In the case of using the same coupler components and tetrazo component, according to the manufacturing method of the present invention, either only the asymmetric disazo compound (represented by general formula B) is produced, or alternatively a weight ratio of the asymmetric disazo compound (represented by general formula B) to the symmetric disazo compound (represented by general formula C) of at least 93/7 can be produced. Furthermore, it is also possible to increase the content of the asymmetric disazo compound to produce a desirable weight ratio of 95/5 or greater. 20 Examples of the non-polar coupler component (I), employed in the present invention, include those represented by the aforementioned general formula (I), wherein two or more types of the aforementioned components can be used together, as long as they are represented by general formula (I). Concrete examples of the non-polar coupler component (I) include acetoacetanilide, acetoacet-o-toluidide, acetoacet-m-xylidide, acetoacet-o-anisidide, acetoacet-p-anisidide., acetoacet-o-chloroanilide, acetoacet-2,5-dimethoxy-4-chloroanilide, and the like. Among these, acetoacetanilide, acetoacet-o-toluidide, and acetoacet-m-xylidide are preferred from the standpoint of markedly improving the transparency according to the present invention. Examples of the polar coupler component (II), employed in the present invention, include those represented by general formula (II), wherein two or more types of the components can be used together, as long as they are represented by general formula (II). Concrete examples of the polar coupler component (II) include 2-acetoacetylaminobenzene sulfonic acid, 3-acetoacetylaminobenzene sulfonic acid, 4-acetoacetylaminobenzene sulfonic acid, 2-acetoacetylamino-5-methylbenzene sulfonic acid, 2-acetoacetylamino-4-chloro-5-methylbenzene sulfonic acid, 2-acetoacetylamino-5-chIoro-4-methylbenzene sulfonic acid, 4-acetoacetylamino-2,5-dichlorobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, 3-acetoacetylamino-4-chloro benzoic acid, 2-acetoacetylamino terephthalic acid, 3-acetoacetylamino isophthalic acid, 4-acetoacetylamino-2-hydroxy benzoic acid and 5-acetoacetylamino-2-hydroxy benzoic acid, and the like. Among these, 4-aceto acetyl aminobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, and 5-acetoacetylamino-2-hydroxy benzoic acid are preferred from the standpoint of markedly WE CLAIM : 1. A method for manufacturing a diazo pigment composition comprising, as essential components, a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, wherein 1) at least a portion of said asymmetric disazo compound represented bv general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof; 2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and 3) an amount of said asymmetric disazo compound represented bv general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,and said phenyl group as 7? contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or 57 potassium: said method comprising the steps of; simultaneously producing the disazo pigment represented by general formula A, and the asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (11) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately CH3COCH2CONH - Z ... General Formula (I) wherein 2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfa group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. 2. A method for manufacturing a disazo pigment composition comprising, as essential components, a disazo pigment represented by general formula A, an asymmetric disazo compound represented by general formula Bs and a symmetric disazo compound represented by general formula C, wherein, 1) at least a portion of said asymmetric disazo compound represented by .general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof; 2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of the disazo compounds other than said disazo pigment; and 3) the weight ratio of said asymmetric disazo compound represented by general formula B to said symmetric disazo compound .represented by general formula C is less than 100/0 parts by weight and at least 93/7 parts by weight when the total weight of the disazo compounds other than said disazo .pigment is 100 parts by weight 58 wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium wherein Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium: 59 said method comprising the steps of: simultaneously producing the disazo pigment represented by general formula A, the asymmetric disazo compound represented by general formula B, and the symmetric disazo compound represented by general formula C by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (1) represented bv.general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately, CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. 3. A method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (1) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, said coupler components are not substantially precipitated, and the tetrazo component reacts immediately 60 wherein Z represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which rnay contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein the carboxyl group and the sulfo group form alkali metal salts with sodium or potassium CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof. 4. A method for manufacturing a disazo pigment composition according to Claim 3, wherein, when the sum of said coupler component (I) represented bv general formula (I) and said coupler component (II) represented by general formula (II) is 100 mol%, said coupling component (I) comprises 85 to 99 mol%, and said coupler component (II) comprises 1 to 15 mol%. 5. A method for improving transparency and flowability of a disazo pigment represented by general formula A comprising the steps of: 1) uniformly adsorbing at least a portion of an asymmetric disazo compound represented by general formula B to the primary particles of said disazo pigment represented by general formula A, or alternatively comprising at least a portion of said asymmetric disazo compound in the crystalline structure thereof, such that 2) a disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula 4 and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and 61 3) an amount of said asymmetric disazo compound represented by general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom, and said phenyl group as Z2contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and.groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium. 6. A method for manufacturing a disazo pigment composition as claimed in any one of claims 1 to 3, wherein the acidic solution is one that is able to maintain the coupling reaction system in the pH range of 3 to 6.9, and contains an acid selected from the group consisting of acetic acid and formic acid. 7. A method for manufacturing a disazo pigment composition as claimed in claim 6, wherein the acid solution is a buffer solution selected from the group consisting of acetic acid-sodium acetate and formic acid-sodium formate. 62 63 8. A method for manufacturing a disazo pigment composition, substantially as herein described, particularly with reference to the examples. A method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, the coupler components are not substantially precipitated, and the tetrazo component reacts immediately. CH3COCH2CONH - Z ... General Formula (I) [wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom]. CH3COCH2CONH - Y ... General Formula (II) [wherein, Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

Full Text

1A
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a disazo pigment composition. More specifically the present invention relates to (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exihibits a superior transparency and flow ability.
This application is based on the patent application No. Hei 10-11503 3, filed in Japan, the contents of which are incorporated herein by reference.
BACKGROUND ART
As examples of conventional methods for improving transparency and flow ability of printing inks containing disazo pigments, Japanese Patent Application, Second Publication No. Sho 45-11026 discloses a method for mixing sulfonic acid compounds into disazo pigments; Japanese Patent Application, Second Publication No. Sho. 55-49087 discloses a method for using a disazo pigment formed by using a mixture of non-polar coupling components and polar coupling components having carboxyl groups and/or sulfo groups as coupling components; and Japanese Patent Application, First Publication No. Sho 63-72762 and Japanese Patent Application, First Publication No. Sho 63-178169 respectively disclose a method of using a disazo pigment composition containing asymmetric disazo compounds which are formed from polar coupling components and non-polar coupling components,

-2-
respectively. Among these disclosures, it is known that a disazo pigment obtained according
to the method disclosed in Japanese Patent Application, Second Publication No. Sho. 55-49087 is more effective in improving the transparency of printing inks, and that a disazo pigment composition disclosed in Japanese Patent Application, First Publication No. Sho 63-178169 is more effective in improving the flow ability of printing inks.
In addition, as a method for improving the transparency, WO97/31067 discloses a method for coupling non-polar coupling components and tetrazo component of the benzidines. However, the extent of improvement in the transparency according to WO97/31067 is remarkably small, and Furthermore, no suggestions regarding the flow ability were mentioned.
With regard to methods for manufacturing -printing inks, there exist a manufacturing method for dispersing wet pigments by means of using a kneader; and a manufacturing method for dispersing powder pigments by means of using a triple roll or beads mill. The choice of the manufacturing method is based mainly on the productivity and demands for the inks. There are several determining factors for the quality required for printing inks; among these, however, it is most important to choose a pigment that is appropriate for the intended use, as well as for the manufacturing method.
In the printing industry, printing inks exhibiting a high transparency are in great demand for their role in improving the clearness of the prints. Additionally, in the printing industry, from the viewpoint of increased productivity, the printing speed is undergoing remarkable improvements. Currently, a printing, machine capable of printing at a speed of 4 meter per second enjoys widespread use as the industry .standard, however, a printing machine capable of printing 15 meter per second has been already developed. In accordance with this increasing printing speed, flow abilities greater than those obtained to date are highly desired for the printing inks.

3
Conventionally, as a method for effectively improving the transparency, Japanese Patent Application, Second Publication No. Sho: 55-49087 is known. The method disclosed in Japanese Patent Application, Second Publication No. Sho, 55-49087 provides for the synthesis of a) a disazo pigment (represented by the following general formula A), which comprises a non-polar coupling component (represented by the following general formula 1) and a non-polar coupling component (represented by the following general formula I); and b) an asymmetric disazo compound (represented by the following general formula B) comprising a polar coupling component (represented by the following general formula II) and a non-polar coupling component (represented by the following general formula I); and (c) a symmetric disazo compound (represented by the following general formula C) comprising a polar coupling component (represented by the following general formula II) and a polar coupling component (represented by the following general formula II), in,the same reaction vessel. The asymmetric disazo compound (represented by the following general formula B) is known for its effects in improving the transparency and flow ability of printing inks.
However, although the method disclosed in Japanese Patent Application, Second Publication No. Sho. 55-49087 produces an asymmetric disazo compound (represented by the following general formula B) effective in improving the transparency, it also results in the large production of a symmetric disazo compound (represented by the following general formula C), which deteriorates the transparency and flow ability. Therefore, this method has failed to provide the necessary transparency desired by the present printing industry.
Additionally, if the speed of dissolving the nompolar coupler component (represented by the following general formula I) into an acidic solution varies from that of the polar coupler component (expresses by the following general formula II), it is impossible to adsorb the asymmetric disazo compound (represented by the following general formula B, which is effective in improving the transparency and flow ability, uniformly to the disazo pigment

4
(represented by the following general formula A), or introduce the asymmetric disazo compound into the crystalline structure. As a result, it becomes impossible to provide the necessary transparency demanded by the present printing industry.
In other words, when the speed of dissolving the polar coupler component (represented by the following general formula II) into an acidic solution is faster than the speed of dissolving the non-polar coupler component (represented by the following general formula I) into an acidic solution, the asymmetric disazo compound (represented by the following general formula B) and the symmetric disazo compound (represented by the following general formula C) are preferentially produced at the initial stage of the coupling reaction, and in the middle to later stages of the coupling reaction, only the disazo pigment (represented by the following general formula A) is produced. Thus, it is impossible to provide the transparency required by the present printing industry.
In contrast, when the speed of dissolving the polar coupler component (represented by the following general formula II) into an acidic solution is slower than the speed of dissolving the non-polar coupler component (represented by general formula I) into an acidic solution, only the disazo pigment (represented by the following general formula A) is produced from the initial to middle stages of the coupling reaction, with the asymmetric disazo compound (represented by the following general formula B) and the symmetric disazo compound (represented by the following general formula C) beingpreferentially produced during the later stage of the coupling reaction. Thus, in a similar manner, it is impossible to provide the transparency required by the present printing industry.
As a result of reasons, similar to the aforementioned, the method disclosed in Japanese Patent Application, Second Publication No. Sho 55-49087 failed to provide the flow ability required by the present printing industry.

5
CH3COCH2CONH - Z ... General Formula (I)
[wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom].
CH3COCH2CONH - Y ... General Formula (II)
[wherein, Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom, and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

[wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from" the group consisting of a methyl group, methoxy group, and chlorine atom].

6

[wherein, Z1 represents a phenyl group, which may .contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

[wherein, Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof).

7
Additionally, as a conventional technology for effectively improving the flow ability, the method disclosed in Japanese Patent Application, First Publication No. Sho. 63-178169 is known. The method disclosed in Japanese Patent Application, First Publication No. Sho. 63-178169 relates to a disazo pigment composition, which is formed by means of synthesizing an asymmetric disazo compound (represented by general formula B) comprising a polar coupling component and a non-polar coupling component, and adding the asymmetric disazo compound (represented by general formula B) to a separately synthesized, disazo pigment (represented by general formula A), comprising a non-polar coupling component and a non-polar coupling component.
However, due to collision of the particles resulting from the stirring during the process of synthesis, or forces imposed during the processes of filtration, drying, and grinding, particles of the disazo pigment, and the asymmetric disazo compound become aggregated, which makes it difficult to adsorb the asymmetric disazo compound to the primary particle surface of the disazo pigment, thereby resulting in a failure to provide tfre flow ability required by the present printing industry. Due to reasons similar to the aforementioned, the above- method is not able provide the transparency required by the present printing industry.
Herein, although an attempt was made at increasing the blending amount of the asymmetric disazo compound (represented by general formula B), a deterioration in the tinting strength occurred, such that the above method was not able to provide a disazo pigment suitable for practical use.
In addition, as a conventional technology for improving the transparency, the method disclosed in W097/3106.7-is also known. The method disclosed in W097/31067 relates to a method for manufacturing a disazo pigment, which is formed by means of coupling the tetrazo component of the benzidine in an acidic solution. This method effectively reduces the

8
aromatic amines, which are by-products of the reaction, by means of improving the coupling reaction rate, resulting in an easier removal of unreacted coupling components. Additionally, it is disclosed that when used as a coloring agent, the resultant pigment results in an improvement in the transparency, the tinting strength, and glossiness thereof. The method
disclosed in WO97/31067 shows a slight improvement in the transparency, when compared with the conventional method for manufacturing a disazo pigment, in which coupling with the tetrazo component of the benzidine is performed in an acidic solution after precipitating the non-polar coupling components.
However, the mechanism for,improving the transparency in the aforementioned method lies in the removal of the unreacted, non-polar coupling components, which have a lower light transmittance and lower transparency (i.e., higher hiding power), compared to those of a disazo pigment. Thus, the extent of the improvement in the transparency is remarkably small, and the method has failed to provide the transparency required by the present printing industry.
Moreover, the method disclosed in WO97/31067 makes no disclosure relating to the flow ability, nor provides any effects of improving the flow ability.
Furthermore, according to the aforementioned conventional method which can produce a disazo pigment derivative (represented by general formula B) comprising an asymmetric disazo compound, and a disazo pigment (represented by general formula A) simultaneously, the maximum weight ratio of the asymmetric disazo compound (represented by general formula B) to the symmetric disazo compound (represented by general formula C) is limited to 90:10. Therefore, this method is still unsatisfactory from the standpoint of a variety of other properties.
DISCLOSURE OF THE INVENTION

9
The object of the present invention is to provide (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exhibits a superior transparency and flow ability. In addition, another object of the present invention relates to a method for improving the properties of the pigment.
The inventors of the present invention have achieved the present invention as a result of intense research to develop (1) a method for manufacturing a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; (2) a disazo pigment that is capable of producing a printing ink with a superior transparency and flow ability; and (3) a printing ink that exhibits a superior transparency and flow ability. In this manner, the inventors have found that the following means are effective in achieving the aforementioned objects. In other words, the present invention provides the following inventions.
A method for manufacturing a disazo pigment composition, wherein a disazo pigment and a disazo compound other than said disazo pigment, which can improve at leasyone property among the transparency and flow ability of the pigment, can be produced simultaneously, by means of performing a coupling reaction of an aqueous coupler solution, containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately.

10
Accordingly the present invention provides a method for manufacturing a disazo pigment composition
comprising, as essential components, a dtsazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, wherein
1) at least a portion of said asymmetric disazo compound represented bv general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof;
2) said disazo pigment composition comprises 98.0 to 72,3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and
3) an amount of said asymmetric disazo compound represented bv general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight

wherein Z1 represents a phenyl group, which may contain 1 .to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain .1 to 4 identicaj or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or

10A
potassium:
said method comprising the steps of;
simultaneously producing the disazo pigment represented by general formula A, and the asymmetric disazo compound represented by general formula 3, by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (1) represented by general formula (1) and a polar coupler component (II) represented by general formula (II) and an aqueous, tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately
CH3COCH2CONH - Z ... General Formula (1) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.
.. The present invention also provides a method for manufacturings disazo pigment composition
comprising, as essential components, a disazo pigment represented by general formula A, an asymmetric disazo compound represented by general formula B, and a symmetric disazo compound represented by general formula C, wherein;
1) at least a portion of said asymmetric disazo compound represented by general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof;
2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of the disazo compounds other than said disazo pigment; and
3) the weight ratio of said asymmetric disazo compound represented by general formula B'to said symmetric disazo compound represented by general formula C is less than 100/0 parts by weight and at least 93/7 parts by weight when the total weight of the disazo compounds other than said disazo pigment is 100 parts by weight

10B

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,_and said phenyl group as Z\contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium

wherein Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1-, to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium:

10C
said method comprising the steps of:
simultaneously producing the disazo pigment represented by general formula A, the asymmetric disazo compound represented by general formula B, and the symmetric disazo compound represented by general formula C by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component-(I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately,
CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH- Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.
The present invention also provides a method for manufacturing a disazo pigment composition
comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound'represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution Containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, said coupler components are not substantially precipitated, and the tetrazo component reacts immediately

10D

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein the carboxyl group and the sulfo group form alkali metal salts with sodium or potassium
CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH - Y '...General Formula(II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof.
The present invention also provides a method for improving transparency and flow ability of a disazo pigment represented by general formula A comprising the steps of:
1) uniformly adsorbing at least a portion of an asymmetric disazo compound represented by general formula B to the primary particles of said disazo pigment represented by general formula A, or alternatively comprising at least a portion of said asymmetric disazo compound in the crystalline structure thereof, such that
2) a disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigrrient represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and

11
3) an amount of said asymmetric disazo compound represented by general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group.consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atoma and said phenyl group as Z2contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.

11A
Furthermore, an object of the present invention are to provide the following disazo
pigment compositions and printing inks.
(1) A disazo pigment composition, which is formed by means of continuously pouring (or injecting) an aqueous coupler solution, containing a non-polar coupler component (I) represented by the above general formula (I) and a polar coupler component (II) represented by the above general formula (II), and an aqueous tetrazo solution

12
containing a tetrazo component of a benzidine, into an acidic solution in a batch stirring tank, such that the ratio of the total molar supply speed of the non-polar coupler component (I) and the polar coupler component (II) to the molar supply speed of the tetrazo component is in the range between 200:80 and 200:99, to induce a coupling reaction.
(2) A disazo pigment composition according to the aforementioned (1), wherein the ratio of the total molar supply speed of the non-polar coupler component (I) and the polar coupler component (II) to the molar supply speed of the tetrazo component is in the range between 200:90 and 200:99.
(3) A disazo pigment composition according to the aforementioned (1) or (2), wherein after continuously pouring (or injecting) an aqueous coupler solution, containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine, into an acidic solution in a batch stirring tank, only the aqueous tetrazo solution is additionally poured (or injected) therein.
(4) A disazo pigment composition according to one of the aforementioned (1), (2), or (3), wherein a buffer solution is present in the acidic solution in the aforementioned batch stirring tank.
(5) A disazo pigment composition according to one of the,aforementioned (1.), (2), (3), or (4), wherein an aqueous coupler solution, in which the total (sum) concentration of/the non-polar coupler component (I) and the polar coupler component (II) is in the range of

13
0.1 to 1 mol/liter; and an aqueous tetrazo solution, the concentration of which is in the range of 0.05 to 0.8 mol/liter, are used.
(6) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), or (5), wherein the ratio of the amount of the acidic solution to the amount of the aqueous coupler solution and the aqueous tetrazo solution poured (or injected) per minute is in the range of 1000:1 to 1000:50.
(7) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), or (6), wherein said non-polar coupler component (I) is at least one compound selected from the group consisting of acetoacetanilide, acetoacet-o-toluidide, and acetoacet-m-xylidide.
(8) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), or (7), wherein said polar coupler component (II) is at least one compound selected from the group consisting of 4-acetoacetylaminobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, and 5-acetoacetylamino-2-hydroxy benzoic acid.
(9) A disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), (7), or (8), wherein said aqueous coupler solution is an alkali solution, and said aqueous tetrazo solution is a hydrochloric acid solution.
(10) A printing ink, which contains a disazo pigment composition according to one of the aforementioned (1), (2), (3), (4), (5), (6), (7), (8), or (9).

14
BEST MODE OF CARRYING OUT THE INVENTION
The method for manufacturing a disazo pigment composition according to the present invention relates to a method for manufacturing a disazo pigment composition, wherein an aqueous coupler solution containing a coupler component (I) and a coupler component (II), arid an aqueous tetrazo solution containing a tetrazo component of abenzidine, are poured into an acidic solution, to induce a coupling reaction.
Herein, a coupling reaction is performed by means of pouring the coupler components into an acidic solution, such that, in the reaction system, none of the coupler components are precipitated, and the tetrazo component reacts immediately. As a. result, as described in greater detail below, at least a portion of the asymmetric disazo compound can be adsorbed uniformly to the primary particles of the aforementioned disazo pigment, or alternatively included in the crystalline structure thereof.
In the present invention, conventionally known and used coupler components may be used as the coupler component (I) and/or the coupler component (II). The pouring method is not particularly limited, however, pouring is continuously performed under normal circumstance. These aspect are described in detail below.
In other, words, according to the method of the present invention, a disazo pigment, which comprises a disazo pigment (represented by general formula A), comprising a non-polar coupling component and a non-polar coupling component; an asymmetric disazo compound (represented by general formula B), comprising a polar coupling component and a non-polar coupling component; and a symmetric disazo compound (represented by general formula C) comprising two polar coupling components, is simultaneously provided, while manufacturing a disazo compound composition with a higher-than-conventional content ratio of the asymmetric disazo compound comprising a polar coupling component and a non-polar

15 coupling component.

[wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom].

[wherein, Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected, from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and containing 1 to_4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

16

[wherein, Z2 represents a phenyl group which may contain 1 to 4 identical or different substituenf group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].
The asymmetric disazo compound (above general formula B) is known to improve the transparency and flow ability of the printing ink.
According to the present invention, by means of synthesizing, simultaneously, this asymmetric disazo compound with a disazo pigment (represented by general formula A), it is possible to uniformly adsorb the asymmetric disazo compqund, which is in a non-aggregate state, to the surface of the primary particles of the disazo, pigment, which is similarly in a non-aggregate state; or alternatively to, form a mixed,crystal comprising the disazo pigment and the asymmetric disazo compound. In this manner, it is possible to introduce a polar group onto the surface of the disazo pigment, and thus to obtain a disazo pigment composition which can provide the printing ink with a superior transparency and flow ability. The effects of the present invention are manifested synergistically in the ability to include a greater (more than the conventional) amount of the asymmetric component, (i.e., a pigment derivative component) in the total disazo pigment composition comprising the

17
disazo pigment derivative, which corresponds to the asymmetric disazo compound, and the disazo pigment, which corresponds to the symmetric disazo compound; and the ability to produce the aforementioned disazo pigment and disazo pigment derivative almost simultaneously, when considering the change of the produced components during the reaction. In other words, even in the situation that both the disazo pigment and the disazo pigment derivative are finally produced, but either said pigment or said derivative is preferentially produced during the reaction, the resultant effects are unsatisfactory, even if the amount of disazo pigment contained is the same as that in the simultaneous synthesis situation. These effects of the invention meet the criteria of simultaneous synthesis.
According to the conventional, method for manufacturing a disazo pigment composition, after the coupler component (I), or both the coupler component (I) and the coupler component (II), are dispersed in an acidic solution, an aqueous tetrazo solution containing a tetrazo component of a benzidine is added thereto.
Both the coupler component (I) and the coupler component (II) are less soluble and dissolve at a slow rate in an acidic solution. On the other hand, the aqueous tetrazo solution containing a tetrazo component of a benzidine reacts extremely well in the aforementioned environment.
Consequently, the rate determination of the reaction between the coupler component (I) and/or the coupler component (II), and the aqueous tetrazo solution, containing a tetrazo component of a benzidine, occurs during the course of dissolving the coupler component (I) and/or the coupler component (II), in an acidic solution.
If the speed of dissolving the.coupler component (I) in an acidic solution differs from that of the coupler component (II), a smaller amount of the asymmetric disazo compound (represented by general formula B), which provides the effects of improving transparency and flow ability, and a greater amount of the symmetric disazo compound (represented by

18
general formula C), which does not contribute towards improving transparency and flow ability, are produced. Thus, it becomes difficult to provide the superior transparency and flow ability, required by the present printing industry.
When comparing the present invention and WO97/31067, the foremost point of difference in the technical structures of the two disclosures lies in that only a non-polar couplercomponenrts used in WO97/31067, while both a non-polar coupler component and polar coupler component are used in the present invention. Accordingly, the molar ratio of the total amount of the coupler components to the amount of the tetrazo component may be selected from within the range conventionally known. For example, the molar ratio of the total amount of the coupler components to the amount of the tetrazo component is in the range between 2:0.8 to 2:0.99. However, the molar supply speed can be expressed more precisely using this molar ratio.
According to the present invention, the total molar supply speed of the coupler component (I) and coupler component (II) is preferably faster than the molar supply speed of the tetrazo component; in this manner, a total molar supply speed of the former equaling 2.0 to 2.5 times the molar supply speed of the tetrazo component may be selectively obtained.
In oilier words, since the present invention provides a disazo pigment composition, the total number of moles of the coupler component (I) and the coupler component (II) supplied is preferably greater than the number of moles of the tetrazo component that are supplied, such that two azo bonds are formed (i.e., to form a 'disazo' compound), wherein the number of moles .of the former is 2.0 to 2.5 times greater than the number of moles of the latter. In particular, the number, of moles of the former is 2.0 to 2.5 times greater than the number of moles of the latter, optimally during,,or at the point of pouring the aqueous tetrazo solution.
A preferred method for manufacturing a.disazo pigment composition according to the

19
present invention comprises performing a coupling reaction by means of continuously pouring an aqueous coupler solution containing a non-polar coupler component (I) and a polar coupler component (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, into an acidic solution, such that the ratio of the total molar supply speed of the coupler component (I) and the coupler component (II) to the molar supply speed of the tetrazo component ranges between 200:80 and 200:99.
In other words, since an aqueous coupler solution concurrently containing a coupler component (I) and a coupler component (II) is used and supplied continuously into an acidic solution, the reaction with the aforementioned aqueous tetrazo solution containing a tetrazo component of a benzidine proceeds, during which time, the aforementioned coupler component (I) and coupler component (II) are either not precipitated, or precipitated in an extremely small amount.
Accordingly, a larger amount of the asymmetric disazo compound (represented by general formuja B), which provides the advantageous effects of improving transparency and flow ability, is produced, while little to none of the symmetric disazo compound (represented by general formula C), which does not contribute towards improving the transparency and flow ability, is produced. Thus, it is possible to provide the necessary transparency and flow ability, required by the present printing industry.
In the case of using the same coupler components and tetrazo component, according to the manufacturing method of the present invention, either only the asymmetric disazo compound (represented by general formula B) is produced, or alternatively a weight ratio of the asymmetric disazo compound (represented by general formula B) to the symmetric disazo compound (represented by general formula C) of at least 93/7 can be produced. Furthermore, it is also possible to increase the content of the asymmetric disazo compound to produce a desirable weight ratio of 95/5 or greater.

20
Examples of the non-polar coupler component (I), employed in the present invention, include those represented by the aforementioned general formula (I), wherein two or more types of the aforementioned components can be used together, as long as they are represented by general formula (I).
Concrete examples of the non-polar coupler component (I) include acetoacetanilide, acetoacet-o-toluidide, acetoacet-m-xylidide, acetoacet-o-anisidide, acetoacet-p-anisidide., acetoacet-o-chloroanilide, acetoacet-2,5-dimethoxy-4-chloroanilide, and the like.
Among these, acetoacetanilide, acetoacet-o-toluidide, and acetoacet-m-xylidide are preferred from the standpoint of markedly improving the transparency according to the present invention.
Examples of the polar coupler component (II), employed in the present invention, include those represented by general formula (II), wherein two or more types of the components can be used together, as long as they are represented by general formula (II).
Concrete examples of the polar coupler component (II) include 2-acetoacetylaminobenzene sulfonic acid, 3-acetoacetylaminobenzene sulfonic acid, 4-acetoacetylaminobenzene sulfonic acid, 2-acetoacetylamino-5-methylbenzene sulfonic acid, 2-acetoacetylamino-4-chloro-5-methylbenzene sulfonic acid, 2-acetoacetylamino-5-chIoro-4-methylbenzene sulfonic acid, 4-acetoacetylamino-2,5-dichlorobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, 3-acetoacetylamino-4-chloro benzoic acid, 2-acetoacetylamino terephthalic acid, 3-acetoacetylamino isophthalic acid, 4-acetoacetylamino-2-hydroxy benzoic acid and 5-acetoacetylamino-2-hydroxy benzoic acid, and the like.
Among these, 4-aceto acetyl aminobenzene sulfonic acid, 2-acetoacetylamino benzoic acid, 3-acetoacetylamino benzoic acid, 4-acetoacetylamino benzoic acid, and 5-acetoacetylamino-2-hydroxy benzoic acid are preferred from the standpoint of markedly

WE CLAIM :
1. A method for manufacturing a diazo pigment composition
comprising, as essential components, a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, wherein
1) at least a portion of said asymmetric disazo compound represented bv general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof;
2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of disazo compounds other than said disazo pigment; and
3) an amount of said asymmetric disazo compound represented bv general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,and said phenyl group as 7? contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or
57

potassium:
said method comprising the steps of;
simultaneously producing the disazo pigment represented by general formula A, and the asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (11) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately
CH3COCH2CONH - Z ... General Formula (I) wherein 2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfa group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.
2. A method for manufacturing a disazo pigment composition
comprising, as essential components, a disazo pigment represented by general formula A, an asymmetric disazo compound represented by general formula Bs and a symmetric disazo compound represented by general formula C, wherein,
1) at least a portion of said asymmetric disazo compound represented by .general formula B is adsorbed uniformly to the primary particles of said disazo pigment represented by general formula A, or is alternatively comprised in the crystalline structure thereof;
2) said disazo pigment composition comprises 98.0 to 72.3% by weight of said disazo pigment represented by general formula A and 2.0 to 27.8% by weight of the disazo compounds other than said disazo pigment; and
3) the weight ratio of said asymmetric disazo compound represented by general formula B to said symmetric disazo compound .represented by general formula C is less than 100/0 parts by weight and at least 93/7 parts by weight when the total weight of the disazo compounds other than said disazo .pigment is 100 parts by weight
58

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom,and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium

wherein Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium:
59

said method comprising the steps of:
simultaneously producing the disazo pigment represented by general formula A, the asymmetric disazo compound represented by general formula B, and the symmetric disazo compound represented by general formula C by means of performing a coupling reaction with an aqueous coupler solution, containing a non-polar coupler component (1) represented bv.general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution, containing a tetrazo component of a benzidine in an acidic solution such as herein described, such that, in the reaction system, none of the coupler components are substantially precipitated, and the tetrazo component reacts immediately,
CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.
3. A method for manufacturing a disazo pigment composition
comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (1) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, said coupler components are not substantially precipitated, and the tetrazo component reacts immediately

60

wherein Z represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which rnay contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group as Z2 contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and groups of alkali metal salts wherein the carboxyl group and the sulfo group form alkali metal salts with sodium or potassium
CH3COCH2CONH - Z ... General Formula (I) wherein Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom
CH3COCH2CONH - Y ... General Formula (II) wherein Y represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof.
4. A method for manufacturing a disazo pigment composition
according to Claim 3, wherein, when the sum of said coupler component (I) represented
bv general formula (I) and said coupler component (II) represented by general formula (II) is 100 mol%, said coupling component (I) comprises 85 to 99 mol%, and said coupler component (II) comprises 1 to 15 mol%.
5. A method for improving transparency and flowability of a disazo pigment
represented by general formula A comprising the steps of:
1) uniformly adsorbing at least a portion of an asymmetric disazo compound
represented by general formula B to the primary particles of said disazo pigment
represented by general formula A, or alternatively comprising at least a portion of said
asymmetric disazo compound in the crystalline structure thereof, such that
2) a disazo pigment composition comprises 98.0 to 72.3% by weight of said
disazo pigment represented by general formula 4 and 2.0 to 27.8% by weight of disazo
compounds other than said disazo pigment; and
61

3) an amount of said asymmetric disazo compound represented by general formula B is at least 93 parts by weight, when the total weight of disazo compounds other than said disazo pigment is 100 parts by weight

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or
different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom

wherein Z1 represents a phenyl group, which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom; and Z2 represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom, and said phenyl group as Z2contains 1 to 4 identical or different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and.groups of alkali metal salts wherein a carboxyl group or a sulfo group forms alkali metal salts with sodium or potassium.
6. A method for manufacturing a disazo pigment composition as claimed in any one of claims 1 to 3, wherein the acidic solution is one that is able to maintain the coupling
reaction system in the pH range of 3 to 6.9, and contains an acid selected from the group consisting of acetic acid and formic acid.
7. A method for manufacturing a disazo pigment composition as
claimed in claim 6, wherein the acid solution is a buffer solution selected from the group consisting of acetic acid-sodium acetate and formic acid-sodium formate.
62

63
8. A method for manufacturing a disazo pigment composition, substantially as herein described, particularly with reference to the examples.

A method for manufacturing a disazo pigment composition comprising the steps of: simultaneously producing a disazo pigment represented by general formula A, and an asymmetric disazo compound represented by general formula B, by means of performing a coupling reaction in which an aqueous coupler solution containing a non-polar coupler component (I) represented by general formula (I) and a polar coupler component (II) represented by general formula (II), and an aqueous tetrazo solution containing a tetrazo component of a benzidine, are simultaneously poured into an acidic solution, such that, in the reaction system, the coupler components are not substantially precipitated, and the tetrazo component reacts immediately.
CH3COCH2CONH - Z ... General Formula (I)
[wherein, Z represents a phenyl group which may contain 1 to 4 identical or different substituent group(s), selected from the group consisting of a methyl group, methoxy group, and chlorine atom].
CH3COCH2CONH - Y ... General Formula (II)
[wherein, Y represents a phenyl group which may contain 1 to 4 identical or different
substituent group(s), selected from the group consisting of a methyl group, methoxy group, hydroxide group, and chlorine atom; and said phenyl group contains 1 to 4 identical or
different substituent group(s), selected from the group consisting of a carboxyl group, sulfo group, and alkali metal salts thereof].

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Patent Number

195544

Indian Patent Application Number

381/CAL/1999

PG Journal Number

30/2009

Publication Date

24-Jul-2009

Grant Date

02-Dec-2005

Date of Filing

23-Apr-1999

Name of Patentee

DAINIPPON INK AND CHEMICALS, INC.

Applicant Address

35-58, SAKASHITA 3-CHOME, ITABASHI-KU, TOKYO

Inventors:

#	Inventor's Name	Inventor's Address
1	HIROHITO ANDO	2-24-9, HINODE, ITAKO-MACHI, NAMEKATA-GUN, IBARAKI-KEN
2	SHIGETO AOKI	1-2-20, KAMISU, KAMISU-MACHI, KASHIMA-GUN, IBARAKI-KEN
3	SADAYUKI TOMIOKA	120-32, MIYATSUDAI, KASHIMA-SHI, IBARAKI-KEN
4	NACATOSHI KOBAYASHI	4687-40, MIYATSUDAI, KASHIMA-SHI, IBARAKI-KEN

PCT International Classification Number

C09B 67/22

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1	10-115033	1998-04-24	Japan