JPH0534384B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) The present invention relates to a blue pigment used in water-based paints, printing inks, etc., and an alkali blue pigment composition suitable as a black toning agent. (Prior Art) Alkali blue pigments are highly polar, highly transparent pigments that have amino groups and sulfone groups, and have strong coloring power. It is already known that alkaline blue pigments usually have extremely strong polarity, and therefore cause strong aggregation and form hard aggregates when using a normal drying method. As a result, it is difficult to disperse in water-based paints, printing inks, etc., and sufficient coloring cannot be obtained. In order to obtain sufficient coloring, there is a method of dispersing an alkali blue pigment into an oil-based varnish using a water-containing press cake, but the pigment content of the press cake is usually low, at less than 40%, and it is difficult to use water-based pigments or printing inks. There are restrictions on the color vehicle used as a dispersion medium. Furthermore, it is already known that alkali blue pigments generally have poor light resistance. As a result, the application of alkali blue pigments to paints, printing inks, etc. is limited. Therefore, an alkali blue pigment with high effective pigment concentration, easy dispersion, stable coloring power during storage, and good light resistance is desired. As a treatment method for improving the coloring power of aqueous paints or printing inks using alkali blue pigments, JP-A-55-139458 describes a method of treatment with water-soluble maleic acid resin, alkyd resin, melamine resin, etc. , JP-A-57-121060 discloses a method of treatment with water-soluble maleic acid resin, alkyd resin, phenolic resin, trimethylolpropane, etc. (Problem to be Solved by the Invention) However, when an alkali blue pigment composition treated with these water-soluble resins is dispersed and mixed with other pigments in an aqueous color vehicle, the alkali blue pigment is removed during storage. The coloring power of the product decreases. Furthermore, there is a drawback that light resistance decreases due to treatment with a water-soluble resin. The purpose of the present invention is to improve these drawbacks, to avoid agglomeration during the manufacturing process, to be easily dispersed in an aqueous color vehicle, and to have little loss of coloring power during storage even when dispersed and mixed with other types of pigments. It is an object of the present invention to provide an alkali blue pigment composition suitable for water-based paints and printing inks, which is also resistant to fading by light. (Means for Solving the Problems) A sulfated product of a rose aniline derivative (hereinafter referred to as a raw material) which is a starting material for the alkali blue pigment composition of the present invention is a rose aniline derivative represented by the following general formula []. (In the formula, X1, X2, X3, and X4 are hydrogen or an alkyl group having 1 to 3 carbon atoms, and R1 and R2 are hydrogen, a phenyl group, or a phenyl group substituted with an alkyl group having 1 to 3 carbon atoms.) Particulate hydrophilic silica is ultrafine silicic acid particles having an average particle diameter of 10 μm or less obtained by a wet method, and its composition is represented by SiO ₂ .nH ₂ O. The alkali-soluble styrene-acrylic or styrene-maleic acid copolymer is a resin represented by the following general formula []. (In the formula, R3 is hydrogen or an alkyl group having 1 to 5 carbon atoms, and R4 is hydrogen or a carboxylic acid group. When dissolving the raw material in an alkaline aqueous solution, the alkali includes sodium hydroxide, potassium hydroxide, Either an inorganic alkali such as lithium hydroxide, an organic amine, or ammonia may be used.Furthermore, the acid used for acid treatment may be an inorganic acid such as hydrochloric acid, sulfuric acid, or phosphoric acid, or an organic acid such as acetic acid or citric acid. Good. Regarding the implementation of the present invention, an alkaline aqueous solution is added to the raw material aqueous slurry so that the pH becomes 11 or higher,
When heated and stirred at 50-100°C, preferably 90-100°C, the raw material becomes brown and dissolves. Particulate hydrophilic silica is added to this solution in a ratio ranging from 10 to 50 parts by weight based on 100 parts by weight of the raw material solid content, and the mixture is stirred. At this time, if the amount of particulate hydrophilic silica added is less than 10 parts by weight, the light resistance will decrease, and if it is more than 50 parts by weight, it will be diluted by the processing agent, the pigment concentration will decrease, and sufficient coloring power will not be obtained. do not have. Furthermore, 10 to 100 parts by weight of raw material solid content
Add 100 parts by weight of alkali-soluble styrene-acrylic or styrene-maleic acid copolymer, heat to 15-100°C, and stir. At this time, if the amount of the alkali-soluble styrene-acrylic or styrene-maleic acid copolymer added is less than 10 parts by weight, the coloring power will decrease, and if it is more than 100 parts by weight, the light resistance will decrease. after that,
When an inorganic or organic acid is added to this solution to make the pH acidic, preferably 4 or less, the solution is heated to 40 to 80°C, preferably 50 to 70°C, and stirred to form a precipitate. By heating this acidic slurry at 90 to 100°C for 15 minutes or more, filtering the generated precipitate, washing with water, drying the residue at 100°C or less, and pulverizing it, it can be applied to and dispersed in aqueous dispersion media. It is possible to obtain an alkali blue pigment composition that has stable coloring power in a medium and exhibits little discoloration due to exposure to light. When the alkali blue pigment composition according to the present invention is dispersed in a water-based printing ink, etc., disadvantages such as a decrease in tinting strength, fading due to light of the colored product, and a decrease in tinting strength that occurs during storage can be significantly improved. It was warm. (Example) Examples are shown below. In the examples, "parts" and "%" are expressed on a weight basis. In the concentration measurement in the examples, the lightness L was measured using a color difference meter using a light scattering method. Example 1 15 parts of sodium hydroxide was added to 120 parts of water to an aqueous slurry containing 40 parts of raw materials, and while stirring,
Dissolve at 100℃. The raw material becomes a brown aqueous solution.
After adding 10 parts of hydrophilic silica with an average particle size of 2.5 μm dispersed in 30 parts of water to this alkaline solution and stirring,
10 parts of an alkaline aqueous solution containing 20% of a styrene-maleic acid copolymer having an average molecular weight of 2500 and an acid value of 175 is added and stirred. 70 with cold water
The solution is cooled to 0.degree. C. and added to 600 parts of a 1.7% aqueous hydrochloric acid solution at 70.degree. C. to precipitate the pigment as an acidic slurry. After heating at 90 to 100°C for 15 minutes while stirring, water was added, cooled to below 50°C, and the deposited precipitate was filtered. Wash the precipitate with warm water at 50°C until the pH of the washing water is 5 or higher, and apply a water-containing paste.
It was dried at below 80℃ and ground in a sample mill. As a result, a finely divided alkali blue pigment composition was obtained which was treated with finely divided hydrophilic silica in a proportion of 25 parts and styrene-maleic acid copolymer in a proportion of 25 parts per 100 parts of the raw material solid content. Example 2 Particulate hydrophilic silica with an average particle diameter of 1.5 μm
The same treatment as in Example 1 was carried out using hydrophilic silica. Example 3 Particulate hydrophilic silica with an average particle diameter of 5 μm
The same treatment as in Example 1 was carried out using hydrophilic silica. Comparative Example 1 The same treatment as in Example 1 was carried out without adding particulate hydrophilic silica and alkali-soluble styrene-acrylic and styrene-maleic acid copolymers to the raw material aqueous slurry. Comparative Example 2 The same treatment as in Example 1 was carried out except that particulate hydrophilic silica was not added to the raw material aqueous slurry. Comparative Example 3 Example 1 without adding alkali-soluble styrene-maleic acid copolymer to the raw material aqueous slurry
The same process was performed. The alkali blue pigment compositions obtained in Examples 1 to 3 and Comparative Examples 1 to 3 above were mixed in a pigment amount of 1
and 70 parts of aqueous white ink base, further added 60 parts of glass beads, and dispersed for 30 minutes with a dissolver, and then mixed with 28 parts of aqueous varnish and 2 parts of isopropanol to prepare a water-based ink. The water-based ink prepared in this way was spread on carton paper using a 0.50 mm barcoder, and the density was measured. Regarding the colored exhibits, an exposure test was conducted for one month in direct sunlight to examine changes in concentration. In addition, the prepared water-based inks were tested after being stored at 50°C for one month to examine changes in concentration and compare storage stability. The results of Examples 1 to 3 and Comparative Examples 1 to 3 are shown in Table 1. The evaluation value of the density was expressed by the brightness difference ΔL measured with a color difference meter, and those for which a single value was obtained were evaluated as having density. From Table 1, it can be seen that the treatment with the styrene-maleic acid copolymer increases the coloring power and provides more stable coloring power, but the coloring power against light decreases. Furthermore, treatment with hydrophilic silica reduces the reduction in coloring power against light, although the coloring power decreases. The method of the present invention, which uses a styrene-maleic acid copolymer and hydrophilic silica, has a high coloring power, shows little change in coloring power during storage, and changes in coloring power against light. It is possible to obtain an alkali blue pigment composition with a small amount of Example 4 The same treatment as in Example 1 was carried out by adding a styrene-acrylic copolymer having an average molecular weight of 1000 and an acid value of 195 instead of the styrene-maleic acid copolymer to the raw material aqueous slurry. Comparative Example 4 The same treatment as in Example 4 was carried out without adding hydrophilic silica. Comparative Example 5 Average particle size added to raw material aqueous slurry
The same treatment as in Example 1 was carried out except that the amount of 2.5 μm hydrophilic silica was changed to 2 parts. Comparative Example 6 Average particle size added to raw material aqueous slurry
The same treatment as in Example 1 was carried out except that the amount of 2.5 μm hydrophilic silica was changed to 28 parts. Comparative Example 7 Example 1 was carried out by changing the amount of styrene-maleic acid copolymer added to the raw material aqueous slurry to 2 parts.
The same process was performed. Comparative Example 8 Example 1 was carried out by changing the amount of styrene-maleic acid copolymer added to the raw material aqueous slurry to 60 parts.
The same process was performed. The results of Example 4 and Comparative Examples 4 to 8 are shown in Table 2. Table 2 shows that the styrene-acrylic copolymer also exhibits the same effects as the styrene-maleic acid copolymer. When the amount of hydrophilic silica added is less than 10 parts, the coloring power against light decreases more than that of the standard pigment, and when it exceeds 50 parts, the coloring power decreases more than that of the standard pigment. Additionally, if the amount of the styrene-maleic acid copolymer added is less than 10 parts, the coloring power will be lower than that of the standard pigment, and if it exceeds 100 parts, the coloring power against light will decrease more than that of the standard pigment. Be looked at. (Effects of the Invention) As described above, by treating the sulfated product of rose aniline derivative with a specific amount of particulate hydrophilic silica and alkali-soluble styrene-maleic acid and styrene-acrylic copolymer, it is possible to It prevents agglomeration, has excellent coloring power, stable coloring during ink storage, and good light resistance.
An alkali blue pigment composition for water-based paints or printing inks can be obtained.

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Claims (1)

[Claims] 1. General formula (In the formula, X1, X2, X3, and X4 are hydrogen or an alkyl group having 1 to 3 carbon atoms, and R1 and R2 are hydrogen, a phenyl group, or a
~ 3 alkyl group-substituted phenyl groups) is a sulfated product of a rose aniline derivative represented by
With respect to 100 parts by weight, fine particulate hydrophilic silica is added in a proportion ranging from 10 to 50 parts by weight, and general formula (In the formula, R3 is hydrogen or an alkyl group having 1 to 5 carbon atoms, and R4 is hydrogen or a carboxylic acid group.) Method 2 for producing an aqueous system having excellent dispersion stability and good light resistance, characterized in that an aqueous system having excellent dispersion stability and good light resistance is produced by the method according to claim 1. Alkaline blue pigment composition with good light resistance