A process for the preparation of a copper phthalocyanine pigment which comprises adding a dry ground mixture of crude copper phthalocyanine containing 0.1 to 20% by weight of a crystal growth inhibitor to a 50 to 90% by weight aqueous solution of sulfuric acid to obtain a sulfuric acid slurry of the dry ground mixture, adding water to the slurry to form a precipitate and recovering it to obtain pigment grade copper phthalocyanine. The copper phthalocyanine pigment prepared according to the present invention is usable in coating materials, inks or plastics.
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1. A process for the preparation of a copper phthalocyanine pigment having an α-polymorph and free of β-polymorph, which comprises the steps of:
(1) adding a dry ground mixture of crude copper phthalocyanine containing 0.1 to 20% by weight of a crystal growth inhibitor to a 50 90% by weight aqueous solution of sulfuric acid to obtain a sulfuric acid slurry of the dry ground mixture, said crystal growth inhibitor being a copper phthalocyanine derivative of formula: ##STR3## wherein CuPc is a copper phthalocyanine group; X1 and X2 are different from each other and each one of them is: (a) a hydrogen or halogen atom and when X1 and X2 are a hydrogen or halogen atom, the number of halogen atoms is at least 2; (b) a substituent selected from the group consisting of the following groups and (i) and (j) are each an integer of 1 to 4 independently from each other: ##STR4## wherein Y is a hydrogen or halogen atom, --NO2, --NH2 or --SO3 H; M is a hydrogen, calcium, barium, strontium or aluminum atom; A is --SO2 --, --(CH2)n -- or --CH2 NHCOCH2 --; each of R1 and R2 is hydrogen atom, a C1-4 alkyl group or R1 and R2 together form a monophthalimedomethyl ring; each of R3, R4, R5 and R6 is a hydrogen atom with the proviso that at least one of R3, R4, R5, and R6 is other than a hydrogen atom or a C1-30 alkyl group; k is an integer of 1 to 4; 1 is the valence of M and each of m and n is an integer of 1 to 8; (2) adding water to the slurry to form a precipitate and (3) recovering said α polymorph copper phthalocyanine free of β-polymorph.
2. A process for the preparation of a copper phthalocyanine pigment as set forth in
3. A process for the preparation of copper phthalocyanine pigment as set forth in
4. A process for the preparation of a copper phthalocyanine pigment as set forth in
5. A process for the preparation of a copper phthalocyanine pigment as set forth in
6. A process for the preparation of a copper phthalocyanine pigment as set forth in
7. A process for the preparation of a copper phthalocyanine pigment as set forth in
8. A process for the preparation of a copper phthalocyanine pigment as set forth in
9. A process for the preparation of a copper phthalocyanine pigment as set forth in
10. A process for the preparation of a copper phthalocyanine pigment as set forth in
(a) a step of adding one part by weight of said dry ground mixture to 3 to 10 parts by weight of a 50 to 65% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 40° to 110°C for 5 to 180 minutes, (b) a step of adding one part by weight of said dry ground mixture to 3 to 10 parts by weight of a 65 to 75% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 180 minutes, and (c) a step of adding one part by weight of said dry ground mixture to 6 to 18 parts by weight of a 75 to 90% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 240 minutes.
11. A process for the preparation of a copper phthalocyanine pigment as set forth in
(a) a step of adding one part by weight of said dry ground mixture to 3 to 10 parts by weight of a 50 to 65% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 40° to 110°C for 5 to 180 minutes, (b) a step of adding one part by weight of said dry ground mixture to 3 to 10 parts by weight of a 65 to 75% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 180 minutes, and (c) a step of adding one part by weight of said dry ground mixture to 6 to 18 parts by weight of a 75 to 90% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 240 minutes.
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1. Field of the Invention
The present invention relates to a process for the preparation of copper phthalocyanine having an α polymorph. More particularly, the present invention relates to a process for the preparation of copper phthalocyanine having an α polymorph which comprises adding a dry ground mixture obtained by dry grinding crude copper phthalocyanine in the presence of a crystal growth inhibitor or a dry ground mixture obtained by dry grinding crude copper phthalocyanine in the absence of any crystal growth inhibitor and mixing the resulting dry-ground crude copper phthalocyanine with a crystal growth inhibitor to an aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture.
2. Description of the Prior Art
A finely divided copper phthalocyanine pigment is used widely and in a large amount in the field of colorant industry because of its beautiful tone, high color strength and excellent performances such as resistance to weather and heat.
Generally, crude copper phthalocyanine is prepared by the reaction of a copper source with urea and phthalic anhydride (or a derivative thereof) or the reaction of a copper source with phthalodinitrile (or a derivative thereof) in the presence or absence of a catalyst such as ammonium molybdate or titanium tetrachloride in an organic solvent such as alkylbenzene, trichlorobenzene or nitrobenzene at a temperature of 120° to 270°C, preferably 170° to 230°C, for 2 to 15 hours, preferably 3 to 7 hours under normal or elevated pressure. However, the copper phthalocyanine molecules thus prepared cause crystal growth one after another in the solvent to give coarse acicular crystals each having a major axis of 10 to 200 μm which are very lowly or no valuable as a coloring pigment for inks, coating materials or plastics.
Accordingly, the crude copper phthalocyanine thus prepared must be finely divided into particles having a high value as a coloring pigment, i.e., one having a size of about 0.01 to 0.5 μm (hereinafter, this operation will be referred to as "pigmentation").
As means for the preparation of a finely divided α-type pigment of copper phthalocyanine, U.S. Pat. Nos. 3,024,247, 2,770,629 and 2,334,812 disclose an acid pasting method comprising treating crude copper phthalocyanine in a state dissolved in a large amount of concentrated sulfuric acid and an acid slurry method comprising preparing a sulfate from crude copper phthalocyanine by the use of a large amount of sulfuric acid having a concentration insufficient for dissolving the pigment therein. However, the sulfate method is particularly problematic in that the obtained pigment is poor in color strength and clarity, that the treatment time is long and that a large amount of sulfuric acid must be used, which is unfavorable in respect of waste water disposal.
As means for improving the color strength and clarity, U.S. Pat. No. 4,386,966 discloses a process for carrying out the sulfate method in the absence of any crystal growth inhibitor. However, this process is also problematic in that the obtained pigment is poor in color strength, transparency or weathering resistance depending upon the conditions of the pigmentation, that copper phthalocyanine having a γ polymorph which causes significant bronzing is formed as a by-product and that the crude copper phthalocyanine to be used is limited to semi-chloro copper phthalocyanine, because remarkable crystal growth occurs when chlorine-free copper phthalocyanine is used.
The inventors of the present invention have intensively studied with the purpose of overcoming the above problems and have found that a copper phthalocyanine pigment having an α polymorph which exhibits a high color strength and a high clarity and is free from one having a γ polymorph can be obtained with a small amount of sulfuric acid for a short time independent of the chlorine content of the crude copper phthalocyanine used, by treating a dry ground mixture of crude copper phthalocyanine containing a crystal growth inhibitor according to the acid slurry method and sulfate method and that the quality level of the pigment can be kept stable against the variation of the treatment conditions such as the concentration or amount of sulfuric acid, temperature or time. The present invention has been accomplished on the basis of these findings.
Namely, the present invention provides a process for the preparation of copper phthalocyanine having an α polymorph which comprises adding a dry ground mixture of crude copper phthalocyanine containing 0.1 to 20% by weight of a crystal growth inhibitor to a 50 to 90% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture, adding water to this slurry to form a precipitate and recovering copper phthalocyanine of pigment grade.
The crude copper phthalocyanine to be used in the present invention can be prepared by the reaction of phthalic anhydride or a derivative thereof (for example, 4-chlorophthalic anhydride) with urea and a copper source or the reaction of phthalodinitrile or a derivative thereof with a copper source in the presence or absence of a catalyst (for example, ammonium molybdate or titanium tetrachloride) in an organic solvent at a temperature of 120° to 270°C, preferably 170° to 230°C, under normal or elevated pressure for 2 to 15 hours, preferably 3 to 7 hours, though the process for the preparation thereof is not particularly limited. Further, the average number of halogen substituents contained per molecule of the crude copper phthalocyanine may be arbitrarily selected from the group consisting of 0 (halogen-free copper phthalocyanine), 0 to 1 (semi-halogenated copper phthalocyanine) and 1 (monohalogenated copper phthalocyanine) depending upon the objective and the use. Generally, semi-halogenated crude copper phthalocyanine is a mixture of copper phthalocyanines different from each other in the number of halogen substituents.
The crystal growth inhibitor according to the present invention includes copper phthalocyanine derivatives and derivatives of organic pigments other than copper phthalocyanine, among which copper phthalocyanine derivatives are preferred. These copper phthalocyanine derivatives are represented by the general formula: ##STR1## CuPc is a copper phthalocyanine residue; X1 and X2 are different from each other and each a hydrogen or halogen atom (when X1 and X2 are each a hydrogen or halogen atom, the number of halogen atoms is at least 2) or a substituent selected from the group consisting of the following groups and i and j are each an integer of 1 to 4 independently from each other: ##STR2## wherein Y stands for a hydrogen or halogen atom, --NO2, --NH2 or --SO3 H; M stands for a hydrogen, calcium, barium, strontium or aluminum atom; A stands for --SO2 --, --(CH2)n -- or --CH2 NHCOCH2 --; R1 and R2, independently from each other, each stand for a hydrogen atom, a C1∼4 alkyl group or R1 and R2 may together form a heterocyclic ring; R3, R4, R5 and R6 each stand for a hydrogen atom (with the proviso that all of R3, R4, R5 and R6 must not be hydrogen atoms at the same time) or a C1∼30 alkyl group; k is an integer of 1 to 4; l is the valence of M and m and n each stand for an integer of 1 to 8.
Examples of the copper phthalocyanine derivative include copper phthalocyaninemonocarboxylic acid, copper phthalocyaninedicarboxylic acid, monophthalimidomethyl copper phthalocyanine, diphthalimidomethyl copper phthalocyanine, di(4,5-dichlorophthalimidomethyl) copper phthalocyanine, mono(4-nitrophthalimidomethyl) copper phthalocyanine, barium salt of di(o-carboxybenzamidomethyl) copper phthalocyanine, mono(o-carboxybenzamidomethyl) copper phthalocyanine, copper phthalocyaninemonosulfonic acid, copper phthalocyaninedisulfonic acid, mono(N,N-dimethyl-1,3-propanediaminosulfonyl) copper phthalocyanine, di(N,N-diethyl-1,3-propanediaminosulfonyl) copper phthalocyanine, mono(N,N-diethyl-1,3-propanediaminoacetaminomethyl) copper phthalocyanine, di-(N,N-diethyl-1-3propanediaminoacetaminomethyl) copper phthalocyanine, N,N-dimethyl-1,3-propanediamine salt of copper phthalocyaninemonosulfonic acid, laurylamine salt of copper phthalocyaninemonosulfonic acid, distearylamine salt of copper phthalocyaninemonosulfonic acid, mono(dimethylaminomethyl) copper phthalocyanine, trichloro copper phthalocyanine and tetrachloro copper phthalocyanine.
According to the present invention, the content of the crystal growth inhibitor in the dry ground mixture of crude copper phthalocyanine is 0.1 to 20% by weight. If the content is less than 0.1% by weight, excessive crystal growth cannot be inhibited, so that no pigment having a high color strength will be obtained. On the contrary, if the content exceeds 20% by weight, the crystal growth will be so depressed that the pigmentation and the transformation into an α polymorph will be uneconomically slow. The content is preferably 0.5 to 10% by weight, still preferably 1 to 7% by weight, because a copper phthalocyanine pigment having a high color strength and a high clarity can be obtained in this content range.
Since the effect of addition of the crystal growth inhibitor is exhibited during pigmentation, the crystal growth inhibitor may be added to crude copper phthalocyanine either before or after the dry grinding to give a pigment having the same excellent quality in either case. Thus, the timing of the addition thereof is not particularly limited.
When a halogenated copper phthalocyanine derivative having 2 to 8 halogen substituents is to be used as the crystal growth inhibitor, a crude copper phthalocyanine having at least one halogen substituent may be preliminarily prepared and used as such, though a crude copper phthalocyanine having no or one halogen substituent may be separately prepared and mixed with the crystal growth inhibitor as described above.
The dry grinding is carried out by the use of a grinder such as a ball mill, vibrating mill or attritor, while the grinding temperature is kept at 100°C or below, preferably at 80°C or below by passing water through a jacket or by directly pouring water on the grinder.
When the dry ground mixture of crude copper phthalocyanine has a β polymorph content exceeding 60% by weight, the mixture is finely divided only to such an insufficient extent that it is impossible to give a pigment having a high color strength. The β polymorph content is calculated according to the equation: Sβ/(Sα+Sβ) based on the peak area (2θ±0.2=15.6°, 16.6°) with respect to the α polymorph and the peak area (2θ±0.2°=18.1°, 18.4°) with respect to the β polymorph determined in the X-ray diffraction pattern.
When crude copper phthalocyanine is used as a starting material in the treatment with sulfuric acid according to the present invention, long time and much energy are necessitated for wetting it with sulfuric acid and converting it into a sulfate thereof, since it is generally in a state of coarse particles. Further, crude copper phthalocyanine cannot be sufficiently converted into a sulfate thereof in an aqueous solution of sulfuric acid having a concentration of less than 75% by weight, so that the effect of finely dividing the coarse particle and that of transforming the β polymorph into the α one are too low to obtain a pigment having a high color strength even if the treatment thereof with sulfuric acid is carried out for a prolonged time.
Meanwhile, a dry ground mixture of copper phthalocyanine is in a state of low-crystallinity agglomerate of fine primary particles and is scarcely valuable as a pigment as such. However, when this mixture is subjected to the treatment with sulfuric acid according to the present invention, it can be easily wetted with sulfuric acid and can be converted into a sulfate for a short time, because the primary particles of the dry ground mixture are very fine in themselves. Further, even in a low-concentration aqueous solution of sulfuric acid having a concentration of 75% by weight or below, the transformation of the β polymorph into the α polymorph can be easily carried out for a short time and the dry ground mixture can be easily formed into a particulate pigment only by virtue of the disagglomeration caused by the crystal growth action of sulfuric acid, since the copper phthalocyanine has already been finely divided in the dry grinding step.
As described above, the preparation of a copper phthalocyanine pigment according to the present invention is superior to the preparation according to the prior art wherein crude copper phthalocyanine is used as a starting material in that the time necessary for the preparation is remarkably shortened and that the amount of the sulfuric acid to be used is reduced. Further, since the particle-dividing effect of dry grinding is higher than that of sulfuric acid, the copper phthalocyanine pigment obtained according to the present invention is composed of very fine particles, has a high specific surface area and exhibits a high color strength and a high clarity.
According to the present invention, the dry ground mixture of copper phthalocyanine is brought into contact with an aqueous solution of sulfuric acid to form a sulfuric acid slurry of the mixture and the disagglomeration of the mixture and the transformation of the β polymorph into the α one are carried out simultaneously. Thus a particulate copper phthalocyanine pigment is recovered.
In the above treatment of the dry ground mixture with sulfuric acid, the crystal growth inhibitor depresses excessive crystal growth caused by the action of sulfuric acid, thus contributing to the formation of a particulate copper phthalocyanine pigment having a large specific surface area. Further, the crystal growth inhibitor is effective in preventing the transformation of the α polymorph into the γ polymorph which is yellowish and opaque and poor in color strength and causes significant bronzing. Therefore, the preparation of a copper phthalocyanine pigment can be carried out in a state stabilized by the crystal growth inhibitor to efficiently obtain a copper phthalocyanine pigment having an α polymorph which exhibits a high color strength and a high clarity.
The process for the preparation of a copper phthalocyanine pigment according to the present invention is characterized by using a dry ground mixture of crude copper phthalocyanine containing a crystal growth inhibitor as a starting material, so that the crude copper phthalocyanine to be used can be arbitrarily selected, though the process of the prior art is limited in the kind of the crude copper phthalocyanine to be used and is affected whether the crude copper phthalocyanine has been dry ground or not. Further, according to the process of the present invention, a copper phthalocyanine pigment superior to that prepared by the process of the prior art in respect of qualities such as coloring strength and clarity can be obtained for a shortened time with a reduced amount of sulfuric acid and the quality level of the pigment can be kept stable against the variation of the preparation conditions.
The concentration of the aqueous solution of sulfuric acid to be used in the present invention is 50 to 90% by weight, preferably 53 to 85% by weight. The temperature of the treatment with sulfuric acid is 0° to 110°C, preferably 0° to 95°C With respect to the relationship between the concentration and the treatment temperature, a lower concentration requires a higher temperature, while a higher concentration requires a lower temperature. When the concentration of the aqueous solution of sulfuric acid is 50 to 65% by weight, the treatment temperature is 40° to 110°C It is preferred that the concentration be 53 to 61% by weight, while the temperature be 55° to 95°C If the concentration is less than 50%, no crystal growth of the dry ground mixture by sulfuric acid will occur to give a pigment poor in color strength and clarity.
The pigmentation involves any of the following steps (a) to (c):
(a) a step of adding one part by weight of the dry ground mixture to 3 to 10 parts by weight of a 50 to 65% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 40° to 110°C for 5 to 180 minutes, or
(b) a step of adding one part by weight of said dry ground mixture to 3 to 10 parts by weight of a 65 to 75% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 180 minutes, or
(c) a step of adding one part by weight of said dry ground mixture to 6 to 18 parts by weight of a 75 to 90% by weight aqueous solution of sulfuric acid to form a sulfuric acid slurry of the dry ground mixture and stirring the slurry at a temperature of 0° to 40°C for 5 to 240 minutes.
If the treatment temperature is higher than 110°C, copper phthalocyanine of a γ polymorph will be formed as a by product to give a pigment poor in color strength and clarity.
When the concentration of the aqueous solution of sulfuric acid is 65 to 90% by weight, the treatment temperature is 0° to 40°C It is preferred that the concentration be 67 to 85% by weight, while the temperature be 0° to 30°C
If the concentration is less than 65% by weight and/or if the treatment temperature is 0° to 40°C, the rate of the pigmentation will be low and the obtained pigment will be poor in color strength and clarity. On the contrary, if the concentration is 65 to 90% by weight, and/or if the treatment temperature is higher than 40°C, the crystal growth exceeding the effect of the crystal growth inhibitor will occur to give a pigment poor in color strength and clarity.
The weight ratio of the aqueous solution of sulfuric acid to the dry ground mixture is between 3 and 18, preferably between 4 and 13. When the concentration of the aqueous solution of sulfuric acid is 50 to 75 (not included) by weight, the weight ratio is preferably between 4 and 9, while when the concentration is 75 to 90% by weight, the weight ratio is preferably between 7 to 13. The weight ratio may be selected with regard to the viscosity of the sulfuric acid slurry of the dry ground mixture and the stirring power of the equipment. If the weight ratio is less than 3, any sufficient stirring cannot be carried out to give a pigment poor in color strength and clarity. The use of an aqueous solution of sulfuric acid in an amount exceeding 18 times by weight as much as the dry ground mixture is uneconomical.
The treatment time is 5 to 240 minutes, preferably 30 to 180 minutes. If the time is shorter than 5 minutes, no sufficient treatment will be attained to give a pigment poor in color strength and clarity. The treatment for 240 minutes or longer is uneconomical, though the treatment is possible.
The slurry prepared above is subjected to precipitation by adding water, stirred at 60° to 95°C for 30 to 120 minutes and filtered. The obtained precipitate was washed with water and recover an objective pigment. The pigment can be used as a pigment paste or a dried pigment. A surfactant and/or other treatment may be added in any step of the process according to the present invention.
The advantages of the process for the preparation of a copper phthalocyanine pigment according to the present invention are as follows:
(1) the obtained pigment is composed of fine particles, has a large specific surface area and exhibits a high color strength and a high clarity,
(2) the treatment time can be shortened and the energy for the treatment is remarkably reduced, which is advantageous in respect of energy saving,
(3) the amount of the sulfuric acid necessitated is reduced, which is advantageous in respect of resource saving, and the waste water disposal is simplified,
(4) the quality level of the pigment can be kept stable against the variation of the preparation conditions,
(5) a high-quality pigment having an α polymorph can be obtained even by the use of sulfuric acid having a concentration lower than 75% by weight, though it has been impossible to obtain the pigment by the use of such lowconcentration sulfuric acid,
(6) the process of the present invention can be applied to an enlarged range to give an optimum pigment depending upon the kind of the crude copper phthalocyanine and the use, and
(7) the productivity can be enhanced, since a crystal growth inhibitor may be added before, during or after the dry grinding step.
Thus, the process of the present invention is extremely valuable in pigment industry.
The copper phthalocyanine pigment prepared according to the present invention is usable in coating materials, inks or plastics.
The present invention will now be described in more detail by referring to the following Examples, though it is not limited to them. In the following Examples, all parts and percentages are by weight.
8 parts of mono(N,N-dimethyl-1,3-propanediaminosulfonyl) copper phthalocyanine was added to 92 parts of crude chlorine-free copper phthalocyanine to obtain a mixture. This mixture was dry ground in an attritor for one hour. One part of the dry ground mixture thus obtained was added to 7 parts of a 70% aqueous solution of sulfuric acid. The obtained mixture was stirred at 30°C for 60 minutes to obtain a slurry. This slurry was diluted with 8 parts of water and the diluted slurry was stirred at 80°C for 60 minutes. The formed precipitate was filtered, washed with water until it became free from acid and dried at 90° to 100°C to obtain 0.95 part of a copper phthalocyanine pigment having an α polymorph.
The same procedure as that described in Example 1 was repeated except that crude chlorine-free copper phthalocyanine was alone dry ground in an attritor for one hour. Thus, a copper phthalocyanine pigment having an α polymorph was obtained.
The same procedure as that described in Example 1 was repeated except that the mixture to be treated was not dry ground. Thus, a copper phthalocyanine pigment having an α polymorph was obtained.
The same procedure as that described in Example 1 was repeated except that the raw materials and dry grinding method were varied as given in Table 1. Thus, copper phthalocyanine pigments each having an α polymorph were obtained.
Crude semi chloro copper phthalocyanine (chlorine content: 3%) was dry ground in a ball mill for 36 hours. 8 parts of N,N-dimethyl-1,3-propanediamine salt of copper phthalocyaninemonosulfonic acid was added to 92 parts of the dry ground crude semi chloro copper phthalocyanine prepared above to obtain a dry ground mixture. One part of this mixture was added to 4 parts of a 60% aqueous solution of sulfuric acid preliminarily heated to 85°C The obtained mixture was stirred at 85°C for 90 minutes to obtain a slurry. This slurry was diluted with 10 parts of water and stirred at 80°C for 60 minutes. The formed precipitate was filtered, washed with water until it became free from acid and dried at 90° to 100°C to obtain 0.94 part of a copper phthalocyanine pigment having an α polymorph.
The same procedure as that described in Example 5 was repeated except that the dry ground crude semi-chloro copper phthalocyanine was alone treated with sulfuric acid. Thus a copper phthalocyanine pigment having an α polymorph was obtained.
The same procedure as that described in Example 5 was repeated except that the crude semi-chloro copper phthalocyanine was not dry ground. Thus, a copper phthalocyanine pigment having an α polymorph was obtained.
The same procedure as that described in Example 5 was repeated except that the raw materials and dry grinding method were varied as given in Table 1. Thus, copper phthalocyanine pigments each having an α polymorph were obtained.
6 parts of copper phthalocyaninemonocarboxylic acid was added to 94 parts of crude monochloro copper phthalocyanine (chlorine content; 5.8%) to obtain a mixture. This mixture was dry ground in a vibrating mill for 5 hours. One part of the dry ground mixture thus prepared was added to 9 parts of an 82% aqueous solution of sulfuric acid. The obtained mixture was stirred at 10°C for 120 minutes to obtain a slurry. This slurry was added to 10 parts of water at 70°C and the obtained mixture was stirred at 70°C for 60 minutes. The formed precipitate was filtered, washed with water until it became free from acid and dried at 90° to 100°C to obtain 0.93 part of a copper phthalocyanine pigment having an α polymorph.
The same procedure as that described in Example 8 was repeated except that the crude monochloro copper phthalocyanine was alone dry ground in a vibrating mill. Thus, a copper phthalocyanine pigment having an α polymorph was obtained.
The same procedure as that described in Example 8 was repeated except that the raw materials and the treatment method were varied as given in Table 1. Thus, copper phthalocyanine pigments each having an α polymorph were obtained.
The pigments prepared in Examples 1 to 10 and Comparative Examples 1 to 5 were examined for specific surface area, color strength and clarity. The results are shown in Table 2.
The specific surface area was determined by the nitrogen adsorption method. A large value thereof indicates a finer primary particle of the pigment. Each of the pigments was dispersed in a synthetic resin type varnish with a Hoover muller to obtain a deep color ink having a pigment content of 20%. The ink was cut with a white ink so as to give a ratio of the blue pigment to the white pigment of 1/10, and the L*, a* and b* values of the cut ink were measured with a color machine. The color strength (CS) was determined by calculation according to the following equation:
CS(%)=10 EXP [{L* (standard)-L* (sample)}/-25+2]
A larger value of CS indicates a higher color strength. Meanwhile, the clarity (CL) was determined by calculation according to the following equation: ##EQU1## A larger value of CL indicates a higher clarity.
| TABLE 1 |
| __________________________________________________________________________ |
| Crystal growth inhibitor Sulfuric |
| addition |
| Dry grinding acid |
| Ex. and |
| Crude copper |
| kind amount |
| method β polymorp |
| treatment |
| Comp. Ex. |
| phthalocyanin |
| (note 1) |
| (note 2) |
| (note 3) |
| method |
| time |
| content (%) |
| method |
| __________________________________________________________________________ |
| Ex. 1 chlorine-free |
| 1 8 before |
| attritor |
| 1 30 7 times as |
| Comp. Ex. 1 |
| chlorine-free |
| -- 0 -- attritor |
| 1 25 much 70% |
| Comp. Ex. 2 |
| chlorine-free |
| 1 8 -- -- -- 100 sulfuric |
| Ex. 2 chlorine-free |
| 2 4 after |
| ball mill |
| 36 35 acid, 30°C |
| Ex. 3 semi-chloro |
| 3 6 before |
| vibrating |
| 5 8 60 min |
| mill |
| Ex. 4 monochloro |
| 4 2 before |
| vibrating |
| 5 0 |
| mill |
| Ex. 5 semi-chloro |
| 5 8 after |
| ball mill |
| 36 10 4 times as |
| Comp. Ex. 3 |
| semi-chloro |
| -- 0 -- ball mill |
| 36 9 much 60% |
| Comp. Ex. 4 |
| semi-chloro |
| 5 8 -- -- -- 15 sulfuric |
| Ex. 6 chlorine-free |
| 6 6 before |
| attritor |
| 1 33 acid, 85°C |
| Ex. 7 monochloro |
| 7 4 before |
| attritor |
| 1 0 90 min |
| Ex. 8 monochloro |
| 8 6 before |
| vibrating |
| 5 0 9 times as |
| mill much 82% |
| Comp. Ex. 5 |
| monochloro |
| -- 0 -- vibrating |
| 5 0 sulfuric |
| mill acid, 10°C |
| Ex. 9 chlorine-free |
| 9 2 after |
| vibrating |
| 5 31 120 min |
| mill |
| Ex. 10 semichloro |
| 10 4 before |
| attritor |
| 1 10 |
| __________________________________________________________________________ |
| (Note 1) |
| 1: mono (N,Ndimethyl-1,3-propanediaminosulfonyl) copper phthalocyanine |
| 2: stearylamine salt of copper phthalocyaninemonosulfonic acid |
| 3: mono(N,Ndiethyl-1,3-propanediaminoacetaminomethyl) copper |
| phthalocyanine |
| 4: monophthalimidomethyl copper phthalocyanine |
| 5: N,Ndimethyl-1,3-propanediamine salt of copper |
| phthalocyaninemonosulfonic acid |
| 6: copper phthalocyaninemonosulfonic acid |
| 7: tetrachloro copper phthalocyanine |
| 8: copper phthalocyaninemonocarboxylic acid |
| 9: barium salt of di(ocarboxybenzamidomethyl) copper phthalocyanine |
| 10: dimethyl distearylamine salt of copper phthalocyaninemonosulfonic aci |
| (Note 2) |
| The amount thereof added to crude copper phthalocyanine (%) |
| (Note 3) |
| before: mixed before dry grinding, after: mixed after dry grinding |
| TABLE 2 |
| ______________________________________ |
| Specific |
| Oil ink test |
| surface Color |
| Ex. and area Comparative strength |
| Clarity |
| Comp. Ex. (m2 /g) |
| pigment (%) (%) |
| ______________________________________ |
| Ex. 1 83 Comp. Ex. 1 120 109 |
| Comp. Ex. 1 |
| 65 -- -- -- |
| Comp. Ex. 2 |
| 42 Comp. Ex. 1 64 73 |
| Ex. 2 84 Comp. Ex. 1 118 108 |
| Ex. 3 92 Comp. Ex. 3 112 105 |
| Ex. 4 95 Comp. Ex. 5 111 104 |
| Ex. 5 87 Comp. Ex. 3 108 107 |
| Comp. Ex. 3 |
| 75 -- -- -- |
| Comp. Ex. 4 |
| 49 Comp. Ex. 3 75 81 |
| Ex. 6 80 Comp. Ex. 1 105 110 |
| Ex. 7 85 Comp. Ex. 5 107 107 |
| Ex. 8 90 Comp. Ex. 5 106 104 |
| Comp. Ex. 5 |
| 78 -- -- -- |
| Ex. 9 83 Comp. Ex. 1 113 106 |
| Ex. 10 86 Comp. Ex. 3 109 108 |
| ______________________________________ |
Nakamura, Koji, Kato, Shigeki, Ide, Yusaku
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| Executed on | Assignor | Assignee | Conveyance | Frame | Reel | Doc |
| Dec 04 1989 | Toyo Ink Manufacturing Co., Ltd. | (assignment on the face of the patent) | / |
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