JPH0643564B2 - Method for producing α-type copper phthalocyanine pigment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention, when blended in a low-viscosity vehicle such as a printing ink or a paint, has a clear reddish-blue color tone and high color tone unique to α-type copper phthalocyanine blue pigment. The present invention relates to a method for producing an α-type copper phthalocyanine blue pigment having a low oil absorption which maintains coloring power and exhibits extremely good fluidity.

(Prior Art) Conventionally, as a method for producing an α-type copper phthalocyanine pigment, a crude copper phthalocyanine is dissolved in 95% by weight or more of agricultural sulfuric acid,
The azide paste method in which this is poured into a large amount of water to make the particles finer, and a sulfate of copper phthalocyanine is formed in sulfuric acid to 60 to 80% by weight, and this is poured into a large amount of water to form a sulfate salt. The acid slurry method of hydrolyzing to make the particles fine is generally performed.

(Problems to be Solved by the Invention) The pigment particles obtained by the former acid paste method are extremely fine, and the color tone is clear and can have a high tinting strength. It has a drawback in that it has a large amount and exhibits extremely high viscosity when blended with a low-viscosity vehicle such as a printing ink or paint, and good fluidity cannot be obtained.

On the other hand, in the latter acid slurry method, the particles formed are significantly coarser than those in the acid paste method, and when blended in a low-viscosity vehicle, low viscosity and good fluidity are exhibited, but the color tone becomes unclear and the coloring power becomes poor. It has the drawback of being extremely reduced.

The α-type copper phthalocyanine pigment according to the prior art as described above has disadvantages in any case, and is not suitable for applications requiring viscosity and fluidity such as printing ink and paint,
The improvement is required.

Therefore, the object of the present invention is to maintain a clear reddish blue color and high tinting strength peculiar to the α-type copper phthalocyanine pigment, and to obtain a sufficiently low viscosity even when compounded in a low-viscosity vehicle such as a printing ink or paint. An object is to provide an α-type copper phthalocyanine pigment showing good fluidity.

(Means for Solving Problems) The above object is achieved by the present invention described below.

That is, according to the present invention, crude copper phthalocyanine is heated and stirred in a mixed solution consisting of three components of concentrated sulfuric acid, water and an organic solvent (alcohol and / or cellosolve), and then poured into a large amount of water to remove the mixed solution. And a method for producing a fine α-type copper phthalocyanine pigment having a low oil absorption amount.

(Preferred Embodiment) Next, the present invention will be described in more detail with reference to preferred embodiments.

The crude copper phthalocyanine used in the present invention may be coarse copper phthalocyanine coarse particles as they are synthesized by a conventionally known method, or the coarse copper phthalocyanine coarse particles may be polished in a ball mill, a vibration mill, a dry attritor or the like. It may be a crude copper phthalocyanine obtained by dry grinding with a crusher, and is not particularly limited, but 1 is particularly preferable.
It is a low-chlorinated copper phthalocyanine containing 1 to 3 chlorine atoms in the molecule.

The mixed solution used in the present invention is a three-component mixed solution of sulfuric acid-water-organic solvent (alcohol and / or cellosolve), and the sulfuric acid concentration of the mixed solution is generally in the range of 60 to 80% by weight. And preferably in the range of 65 to 70% by weight.

The concentration of the organic solvent in the mixed solution is generally in the range of 0.5 to 30% by weight, preferably 3 to 15% by weight.

The alcohol used as the organic solvent is preferably methanol, ethanol, propyl alcohol, isopropyl alcohol, butanol, lower easily water-soluble alcohols such as isobutanol, and as cellosolve, methyl cellosolve, ethyl cellosolve, butyl cellosolve and other easily water-soluble alcohols. Cellosolve is preferred, and these alcohols and cellosolves can be used alone or in combination.

The mixed solution may be used in an amount of 5 to 15 times the weight of the crude copper phthalocyanine used, the heating temperature is in the range of 10 to 80 ° C., preferably 35 to 45 ° C., and the heating heat time is 0.5. To 8 hours, preferably 3 to 4 hours.

(Examples) The present invention will be described more specifically with reference to Examples and Comparative Examples below.

Example 1 2,626 g of 98% concentrated sulfuric acid and 1,146 g of water were mixed, and in this, 64 g of methanol and butyl cellosolve 6 were mixed.
4 g is added to prepare a mixed solution having a sulfuric acid concentration of 66% by weight.
260g of crude copper phthalocyanine with temperature set at 45 ° C
Was added and stirred at this temperature for 4 hours, then 15,000 g
Pour into the water under stirring. After stirring for 15 minutes, filtration, washing with water and drying were performed to obtain 250 g of α-type copper phthalocyanine pigment.

Example 2 2,729 g of 98% concentrated sulfuric acid and 1,058 g of water were mixed, 263 g of methanol was added thereto, and the sulfuric acid concentration was 66.
Make a wt% mixture. Set the temperature to 40 ° C,
Dry-milled crude copper phthalocyanine (5) in the dry attritor.
225 g (0 g obtained by dry milling for 30 minutes) is added, stirred at this temperature for 3 hours, and then poured into 15,000 g of water with stirring. The mixture was stirred for 15 minutes, filtered, washed with water and dried to obtain 216 g of an α-type copper phthalocyanine pigment.

Comparative Example 1 (acid paste method) Crude copper phthalocyanine 2 in 2,600 g of 98% concentrated sulfuric acid
After adding 60 g and stirring at 60 ° C. for 2 hours to completely dissolve the crude copper phthalocyanine in sulfuric acid, the mixture is poured into 15,000 g of water with stirring. After stirring for 15 minutes, filtration, washing with water and drying were performed to obtain 250 g of α-type copper phthalocyanine pigment.

Comparative Example 2 (Acid Slurry Method) 98% sulfuric acid 3,105 g and water 796 g were mixed to obtain 78.
Make sulfuric acid at a concentration by weight. The temperature is set to 40 ° C., 260 g of crude copper phthalocyanine is added, and the mixture is stirred at this temperature for 4 hours and then poured into 15,000 g of water with stirring. After stirring for 15 minutes, filtration, washing with water and drying were performed to obtain 250 g of α-type copper phthalocyanine pigment.

Comparative test results of the pigments obtained in the above Examples and Comparative Examples (a) Preparation of pigment dispersion Vehicle (modified linseed oil) 50 parts by weight Pigment 10 parts by weight The above composition was kneaded with a small three-roll mill to prepare the pigment vehicle. Disperse completely in it to make ink and use it as a sample.

(B) Measurement of fluidity 5 g of the sample obtained in (a) above is placed on a glass plate, which is tilted at an angle of 60 degrees, and the flow-down distance of the sample after 2 hours is measured.

(C) Hue Measurement result of printed matter of the sample obtained in (A) Main wavelength: Hue Purity: Sharpness (D) Coloring power 1 g of the sample of Comparative Example 1 obtained in (A) and white ink 1
1 g of each sample is mixed with white ink based on the coloring density when 0 g is mixed, and the amount of white ink used until the same coloring density as in Comparative Example 1 is used is determined.

(Effect) As shown by the test results, it was found that the one according to the present invention can obtain extremely good fluidity without much loss in hue and coloring power as compared with the one according to the prior art.

Claims (7)

[Claims] 1. A method of removing crude copper phthalocyanine by injecting it into a large amount of water after heating and stirring in a mixed solution consisting of three components of concentrated sulfuric acid, water and an organic solvent (alcohol and / or cellosolve). A method for producing a fine α-type copper phthalocyanine pigment having a low oil absorption and comprising: 2. The production method according to claim 1, wherein the crude copper phthalocyanine is coarse copper phthalocyanine with coarse particles as synthesized. 3. The crude copper phthalocyanine obtained by dry grinding the as-synthesized coarse particles with a grinding machine such as a ball mill, a vibration mill or a dry attritor.
The manufacturing method described in. 4. The method according to claim 1, wherein the crude copper phthalocyanine is a low-chlorinated copper phthalocyanine containing 1 to 3 chlorine atoms in one molecule. 5. The sulfuric acid concentration in the mixed solution is 60 to 80% by weight.
The manufacturing method according to claim 1, wherein 6. The manufacturing method according to claim 1, wherein the heating temperature is in the range of 10 ° C. to 80 ° C. 7. The production method according to claim 1, wherein the stirring time is in the range of 0.5 to 8 hours.