JP3533678B2 - Method for producing printing ink or pigment paste for printing ink - Google Patents

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention uses an α-type fine granular coarse copper phthalocyanine pigment or its derivative having an average primary particle diameter of 0.1 μ or less, and directly forms β-type without forming a powdery pigment. The present invention relates to a method for producing a printing ink or a pigment paste for a printing ink containing a copper phthalocyanine pigment or its derivative.

[0002]

2. Description of the Related Art Copper phthalocyanine is produced by a synthetic method called the Weyler method (urea method) or the phthalonitrile method. The copper phthalocyanine that has been synthesized is called crude and has a large particle size and impure blue color. It is a β-type needle crystal (about 20-200μ), and it is not suitable for printing inks and paints because it has no coloring power or clarity as a pigment. Therefore, it is necessary to reduce the primary particle size to an appropriate size (0.01 to 0.3 μ) and adjust the crystal type to a crystal type suitable for the purpose of use. This typical method is solvent-
It is called the salt-milling method, and is a method of wet grinding by adding an organic solvent that promotes crystal transition and an auxiliary agent for mechanical grinding (salt, mirabilite, etc.) to the crude.
After grinding, the organic solvent and salt are separated and collected. The pigment in the water phase is washed with water and acid several times, filtered, dried and pulverized to be a powder pigment for inks and paints, which has the optimal coloring property, gloss, and
And have a hue.

However, the solvent-salt-milling method requires several times as much salt as the crude pigment. It takes time to crush and knead the crude pigment. There are drawbacks such as the need for treatment such as removal and recycling of salts and organic solvents, which takes time and cost.

Further, since the dried pigment which has been refined thereafter has been agglomerated, it is necessary to again knead the meat. Immediately after filtration, a wet cake, which is a clay-like pigment having a water content of 40 to 80%, is kneaded in a kneader with a solvent suitable for ink and a varnish,
There is also a flash manufacturing method in which the pigment is extracted into the varnish phase to directly produce the ink, but the drying and pulverizing operation of the pigment and the re-kneading meat for forming the ink are not necessary, but the kneading operation is necessary for the phase conversion.

On the other hand, among existing methods for crushing crude, for example, dry crushing using an atomizer, a ball mill, an attritor or the like has the highest crushing efficiency. However, when this method is used, a part of the crude pigment whose crystal system is originally β-type is converted to α-type, and therefore it must be converted back to β-type by heat or solvent treatment. Japanese Examined Patent Publication No. 55-6670 discloses that a fine particulate coarse copper phthalocyanine pigment having a primary particle size of 1.0 μ or less or a derivative thereof is suspended at room temperature to 200 ° C. in a varnish suitable for printing ink. Then, a method for directly producing a printing ink and a pigment paste for a printing ink containing a dark-colored copper phthalocyanine pigment or a derivative thereof without changing the crude pigment into a pigment form in advance is described. However,
In Japanese Examined Patent Publication No. 55-6670, crystal growth is stopped by adding a crystal growth inhibitor such as nonylphenol. However, the crystal growth inhibitor is not preferable because it adversely affects printability particularly in the case of offset ink.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an α-type fine particulate copper phthalocyanine pigment or a derivative thereof, which is obtained by dry-milling a crude pigment raw material called crude and has an average primary particle diameter of 0.1 μm or less. Another object of the present invention is to provide a printing ink or a pigment paste for a printing ink, which contains the β-type copper phthalocyanine pigment or its derivative and is excellent in printability.

That is, a crude copper phthalocyanine pigment called crude having a particle size of about 20 to 200 μm is efficiently dry-ground by, for example, a conventionally known crusher to obtain a particle size of
After preparing a fine-grained crude pigment of 0.1 μm or less, this was leveled with a varnish for printing ink without using a crystal growth inhibitor.
60 to 200 ℃ in the processing liquid that does not become a mixed system
Crocodile for printing ink after maintaining in suspension in range
Of the varnish and extract the processing liquid.
By excluding Ri, easily superior printing ink or printing ink pigment paste offset printing suitability containing β type copper phthalocyanine pigment or derivative thereof to provide a method for manufacturing in small steps compared with the prior art, the manufacture of ink It is possible to save a large amount of cost.

[0008]

In the present invention, the average particle size of the primary particles is 0.1 μm.
The following α-type fine granular crude copper phthalocyanine pigment or its derivative is maintained in a suspension state in the range of 60 ° C to 200 ° C in a processing liquid that does not form a homogeneous mixture with a printing ink varnish, and then printed. The present invention relates to a method for producing a printing ink or a pigment paste for a printing ink containing a β-type copper phthalocyanine pigment or a derivative thereof, which comprises adding a varnish for an ink, extracting a pigment from the varnish, and removing a treating liquid.

Further, in the present invention, the average particle size of the primary particles is
The α-type fine granular crude copper phthalocyanine pigment having a particle size of 0.1 μ or less is characterized in that the average particle size of the primary particles is obtained by dry grinding of a copper phthalocyanine pigment or a derivative thereof having a particle size of more than 1.0 μ. And a method for producing a printing ink or a pigment paste for a printing ink.

The present invention also provides a method for producing the above-mentioned printing ink or pigment paste for printing ink, characterized in that the temperature maintained in suspension is 60 to 120 ° C. and no crystal growth inhibitor is used. Regarding

In order to obtain an α-type fine granular coarse copper phthalocyanine pigment (hereinafter referred to as fine granular coarse pigment) having an average primary particle diameter of 0.1 μm or less, for example, the crude is atomizer, ball mill, or attritor. It can be easily obtained by a known method such as dry pulverization with.
At this time, the β-type fine granular crude copper phthalocyanine pigment may be mixed in the fine granular crude pigment.

[0013]

Next, the fine granular crude pigment is sufficiently wet and suspended with a processing liquid which does not form a uniform mixture with the printing ink varnish.

As the varnish for printing ink, for example, in the case of offset printing, flaxseed oil, isomerized flaxseed oil, millet oil,
Drying oils such as dehydrated castor oil, fish oil, and deer oil, and polymerizing drying oils; Urethane oils, maleated oils, cyclopentadienylated oils formed from these drying oils; drying oils; Alkyd resins such as modified alkyd resins, urethane-modified alkyd resins, acrylic modified alkyd resins, and phenol-modified alkyd resins; drying oil fatty acid-modified epoxy ester resins; Examples thereof include hydrocarbon resins that are derived, and these can be used alone or in combination of two or more kinds.

As a solvent for printing ink, for example, in the case of offset ink, light oil, kerosene, terpen, mineral spirits and the like can be mentioned. In the present invention, any solvent suitable for the ink may be used alone or in combination of two or more kinds regardless of the kind.

As the processing liquid which does not form a homogeneous mixture with the varnish, for example, in the case of offset ink, volatile methanol, ethanol, isopropyl alcohol, n-propyl alcohol, n-butanol, Sec-butanol, te
Lower alcohols such as rt-butanol can be used, and these may be used alone or in combination of two or more.
In the present invention, a liquid other than the lower alcohol may be used as long as it is a liquid that does not form a homogeneous mixture with the varnish.

In order to produce an ink, finely divided coarse pigment is mixed into a treating liquid and the finely divided coarse pigment is sufficiently wetted.
Suspend in the range of 60 ° C to 200 ° C. At this time, when the treatment temperature exceeds 200 ° C., although the crystal conversion from α-type to β-type easily proceeds in a short time, the crystal growth is promoted, and the diameter of the primary particles of the original fine particulate crude pigment is It is not preferable because it grows to 2 to 3 times the particle size. When the treatment temperature is lower than 60 ° C., the above-mentioned crystal growth is suppressed, but the crystal conversion from α-type to β-type requires a long time, which is not preferable.

A stirring device is required depending on the fluidity of the suspension. The suspension is preferably carried out for 5 minutes to 6 hours until the crystal form of the pigment is converted to 99.0% or more and β form. When finely divided crude pigment is suspended in a varnish for printing ink or a processing liquid that does not form a homogeneous mixture with the solvent for printing ink, the varnish for printing ink and, if necessary, the solvent for printing ink before kneading And the pigment is extracted into the varnish for printing inks and the processing liquid is removed mechanically, for example by decantation of the phase-separated liquid and the rest by evaporation, for example under reduced pressure, before printing the pigment. The meat is dispersed in the ink varnish by a kneading machine (eg roll mill, bead mill). And solvent for printing ink, varnish for printing ink,
Alternatively, a printing ink or a pigment paste for printing ink having a desired pigment content and viscoelasticity value can be obtained by adding other additives.

The weight ratio of the total amount of the varnish for the printing ink and the solvent for the printing ink to the fine granular crude pigment is such that if the above total amount is used in an amount more than the blending weight ratio in the final ink product, it is necessary to remove an excessive amount later. Therefore, it is desirable that the compounding ratio of the final ink product is within the range. Further, when the concentration of the finely divided coarse pigment is too thick or too thin during suspension or kneading, stirring becomes difficult, so the mixing ratio is such that the suspension or the like has a viscoelasticity value suitable for a stirring device or a kneading machine. It is desirable to be within the range. That is, the weight ratio of the total amount of the varnish for the printing ink and the solvent for the printing ink to the fine particulate coarse pigment is 10: 1 to 1: 1.
It is preferable that

The ratio of the processing liquid that does not form a uniform mixture with the printing ink varnish and the finely divided coarse pigment may be in any range, but generally it is in the range of 10: 1 to 1: 1 (weight ratio). preferable.

The production method according to the present invention is the most energy-efficient method for producing a printing ink or a pigment paste for a printing ink from a finely divided coarse pigment, and is a method for producing a printing ink or a pigment paste for a printing ink. Enables simplification over time. In the ink produced by this method, the pigment has an extremely uniform particle size distribution, and is excellent in coloring power, gloss and fluidity.

The production method according to the present invention can be applied not only to offset printing inks but also to gravure printing inks, screen printing inks, etc. or printing inks using two or more β-type copper phthalocyanine pigments. Can be similarly applied. Further, it is of course possible to use other pigments, desiccants, auxiliaries, etc. during the kneading at the time of preparing the printing ink.

[0024]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. The percentages in the examples and comparative examples are by weight.

[0025]

Example 1 15 parts of Fastgen Blue GT-1 (a fine granular crude pigment manufactured by Dainippon Ink and Chemicals, Inc.) was mixed with 50 parts of ethanol to wet Firstgen Blue GT-1 to 70
Suspend for 45 minutes at 0 ° C. with stirring under moist conditions.
After that, 80 parts of varnish A was further added, the pigment was extracted into the varnish, ethanol was removed by decantation, and the remaining ethanol was removed by evaporation by vacuum degassing at 80 ° C., and then No. 6 solvent 5 Parts,
Knead and disperse with a flat type three-roll mill with a width of 900 mm,
A pigment paste for printing ink was prepared.

Example 2 15 parts of fastgen blue GT-1 (fine granular crude pigment manufactured by Dainippon Ink and Chemicals, Inc.) was mixed with 50 parts of ethanol, and the firstgen blue GT-1 was thoroughly wetted to 70 parts.
Suspend for 45 minutes at 0 ° C. with stirring under moist conditions.
After suspending, the mixture is further kneaded and dispersed by a large bead mill kneading machine having an actual capacity of 26 liters at 100 kg / hr and kneading temperature of 80 ° C. Then 80 parts of varnish A was added, the pigment was extracted into the varnish, ethanol was removed by decantation with a twin-screw tank mixer, and the remaining ethanol was removed by evaporation by vacuum degassing at 80 ° C., and then 6 5 parts of No. solvent was added, and the mixture was kneaded and dispersed by a flat type three-roll mill having a width of 900 mm to prepare a pigment paste for printing ink.

Comparative Example 1 15 parts of Fastgen Blue GT-1 (fine granular crude pigment manufactured by Dainippon Ink and Chemicals, Inc.) was mixed with nonylphenol 5
Part, xylene 5 parts, and varnish A 75 parts mixed in the processing solution to wet First Gen Blue GT-1 sufficiently
Suspend for 15 minutes with stirring at ℃ wet.
After suspending, the mixture was kneaded and dispersed at 25 to 40 ° C. with a flat type three-roll kneader having a width of 900 mm to prepare a pigment paste for printing ink.

Printing inks were prepared by mixing 99 parts of the pigment paste for printing inks obtained in each of the examples and comparative examples with 1 part of a drier (5% by weight manganese naphthenate solution), and the printability of each printing ink, The hue and gloss were measured. The results are shown in Table 1.

[0030]

[Table 1] *) The printing test was evaluated using a Roland RVK200 printing machine.

As is apparent from Table 1, the printing inks obtained according to the respective examples have good printability, but the printing inks obtained according to the comparative examples have the same properties as nonylphenol. Since a surfactant is used, the printability is greatly adversely affected (floatability, etc.), and the printability is poor, so that it is not practical.

The particle diameters of primary particles and the crystal content of the pigments before and after the treatment were measured.

[0033]

[Table 2] *) Particle size and crystal type are measured by electron microscope and X-ray analysis, respectively.

As is apparent from Table 2, according to the present invention, the crystal form is 9 while maintaining the particle size of the primary particles at 0.02 μm or less.
It can be seen that 9% or more can be converted into β-type crystals.

[0035]

According to the present invention, a printing ink containing a β-type copper phthalocyanine pigment or a derivative thereof and having excellent printability can be produced extremely efficiently.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Yoshiaki Arai 14-14 Iwagasakidai, Sawara-shi, Chiba (72) Inventor Kazuo Kamei 3-14-6 Sakae Ina-cho, Kitadachi-gun, Saitama (56) References Japanese Patent Publication Sho 55-6670 (JP, B1) (58) Fields investigated (Int.Cl. ⁷ , DB name) C09D 11/00-11/20 C09D 17/00

Claims (3)

(57) [Claims] 1. An α-type fine granular copper phthalocyanine pigment or its derivative having an average primary particle diameter of 0.1 μm or less is added to methanol, ethanol or isopropyl alcohol.
, N- propyl alcohol, n- butanol, Sec- butano
And at least one selected from the group consisting of tert- butanol
After maintaining in suspension at a range of 200 ° C. from 60 ° C. in a liquid, adding a printing ink varnish, it extracts the pigment into the varnish, characterized in that removing the processing liquid β A method for producing a printing ink or a pigment paste for a printing ink, which comprises a copper phthalocyanine pigment or a derivative thereof. 2. An α-type fine granular coarse copper phthalocyanine pigment having an average primary particle diameter of 0.1 μ or less is a dry pulverized copper phthalocyanine pigment or a derivative thereof having an average primary particle diameter of more than 1.0 μ. The method for producing a printing ink or a pigment paste for a printing ink according to claim 1, which is obtained by 3. The method for producing a printing ink or a pigment paste for a printing ink according to claim 1, wherein the temperature for maintaining the wet suspension state is 60 ° C. to 120 ° C. and no crystal growth inhibitor is used. .