JPH0819345B2 - Pigment composition and method for dispersing pigment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a diketopyrrolopyrrole pigment composition excellent in usability, particularly non-aggregation and fluidity, and a dispersion method.

(Prior Art) In general, practically useful pigments that exhibit a vivid color tone and high coloring power in various coating or ink compositions consist of fine particles. However, it is difficult to obtain a stable dispersion of fine pigment particles when dispersed in non-aqueous vehicles such as offset inks, gravure inks and paints, which has a significant impact on the manufacturing process and the value of the resulting product. It is known to cause various problems.

For example, dispersions containing pigments consisting of fine particles often have high viscosities, which not only makes it difficult to remove and transport the product from the disperser, but in the worse case, it causes gelation during storage and is used. It can be difficult. When different kinds of pigments are mixed and used, color unevenness or remarkable decrease in coloring power may be caused in a color-developed product due to reduction in color separation or sedimentation due to aggregation. Furthermore, the coating surface of the color-developed product may have poor gloss, poor leveling, and other defective states.

Although not directly related to the pigment dispersion, some organic pigments have a decrease accompanied by a change in the crystal state of the pigment.

That is, in non-aqueous vehicles such as offset inks, gravure inks, and paints, the crystal particles of energetically unstable pigments change their size and form and shift to a stable state. The commercial value may be impaired due to a decrease in coloring power, generation of coarse particles, and the like.

In order to solve the above-mentioned various problems, many proposals have been made mainly on copper phthalocyanine and quinacridone pigments.

The contents can be roughly classified into the following two when classified according to the technical method.

The first method involves coating the surface of pigment particles with a colorless compound such as silicon oxide, aluminum oxide and tertiary butyl benzoic acid as disclosed in US Pat.

The second method is, as typified by JP-B-41-2466 and USP2855403, using an organic pigment as a base skeleton and introducing a substituent such as a sulfone group, a sulfonamide group, an aminomethyl group or a phthalimidomethyl group into a side chain. This is a method of mixing the compounds obtained by.

The second method has a remarkably large effect on the non-aggregation property of the pigment in the non-aqueous vehicle, the crystal stability, etc. as compared with the first method, and is very advantageous even when judged from the ease of manufacturing the pigment composition. Is the way.

At present, few compounds are known to be effective against diketopyrrolopyrrole pigments, but for diketopyrrolopyrrole pigments, the composition disclosed in JP-A-62-295966 is used. It has been known. In the pigment field,
Whether or not the dispersion aid is effective cannot be known without conducting an experiment, but the effect is not necessarily good when used in combination with a phthalimidomethyl derivative of quinacridone.

(Problems to be Solved by the Invention) The present invention is intended to obtain a stable dispersion having excellent non-aggregation and fluidity when producing offset inks, gravure inks, paints, etc. comprising diketopyrrolopyrrole pigments. And a method for dispersing the same.

[Structure of Invention]

(Means for Solving the Problems) The present invention is based on 100 parts by weight of the diketopyrrolopyrrole pigment and the quinacridone derivative represented by the general formula [I] 0.3.
~ 30 parts by weight of the pigment composition and dispersion method.

The diketopyrrolopyrrole pigment is a compound represented by the formula (II). These compounds are described in U.S. Pat. No. 4,415,685.
, European Patent Application Publication No. 133,156 or Japanese Patent Application Publication (A) 61-120861,61-183363,62-
It is known from 149759 and the like.

(The symbols in the formula are the same as above.) The quinacridone derivative according to the present invention is a compound represented by formula (I).

(The symbols in the formula are the same as above.) The compound represented by the formula (I) is prepared by first chloroalkylating a quinacridone compound by a conventional method, and then reacting the obtained chloroalkylquinacridone with an amine. Can be manufactured. Solvents used for the reaction of chloroalkylquinacridone with amines include water or methanol, ethanol, propyl alcohol, isopropyl alcohol, acetone, dioxane, N, N-dimethylformamide, N-methyl-2-pyrrolidine, dimethyl sulfoxide. Examples include general organic solvents such as cyclohexane, toluene, and xylene, but it is also possible to use the reaction components amines as they are as a solvent. In this reaction, a basic compound such as sodium hydroxide, sodium carbonate, potassium hydroxide, potassium carbonate, triethylamine, pyridine or p-dimethylaminopyridine can be used in combination as an acid binder.

Examples of amines include dimethylamine, diethylamine, N-ethylisopropylamine, N-
Ethylpropylamine, N-methylbutylamine, N-methylisobutylamine, N-butylethylamine, N-tert-
Butylethylamine, diisopropylamine, dipropylamine, N-sec-butylpropylamine, dibutylamine, di-sec-butylamine, diisobutylamine, N
-Isobutyl-sec-butylamine, diamylamine,
Diisoamylamine, dihexylamine, di (2-ethylhexyl) amine, dioctylamine, N-methyloctadecylamine, didecylamine, diallylamine, N-
Ethyl-1,2-dimethylpropylamine, N-methylhexylamine, 2-hydroxymethylaminoethanol, dioleylamine, distearylamine, piperidine, 2-
Pipecoline, 3-Pipecoline, 4-Pipecoline, 2,4-Lupetidine, 2,6-Lupetidine, 3,5-Lupetidine, 3-Piperidine Methanol, Pipecolic acid, Isonipecotic acid, Methyl isonicopetate, Ethyl isonicopetate, 2-Piperidine Examples thereof include ethanol, pyrrolidine, and 3-hydroxypyrrolidine.

The quinacridone derivative obtained in the present invention was added to the diketopyrrolopyrrole pigment in an amount of 0.
3 to 30 parts by weight is preferable. If it is less than 0.3 parts by weight, the effect of the pigment dispersant obtained in the present invention cannot be obtained, and if it is used in excess of 30 parts by weight, the effect of the amount used cannot be obtained.

Examples of the method of using the quinacridone derivative according to the present invention include the following methods.

1. A pigment composition obtained by previously mixing a pigment and a quinacridone derivative is added to a non-aqueous vehicle or the like and dispersed.

2. Add pigment and quinacridone derivative separately to non-aqueous vehicle and disperse.

3. The pigment and the quinacridone derivative are separately dispersed in a non-aqueous vehicle or the like in advance, and the resulting dispersion is mixed. In this case, the quinacridone derivative may be dispersed only with the solvent.

4. After dispersing the pigment in a non-aqueous vehicle, add the quinacridone derivative to the resulting dispersion.

Etc., and any of these can achieve the desired effect.

As the method for preparing the pigment composition shown in the above 1, the desired effect can be obtained by simply mixing the pigment powder and the powder of the quinacridone derivative according to the present invention.
A quinacridone derivative is deposited on the pigment surface by mechanically mixing with a roll, attritor, super mill, various crushers, or the like, or by adding a solution containing the quinacridone derivative according to the present invention to a suspension system of pigment or water or an organic solvent. Even better results can be obtained by performing a close mixing method such as co-dissolving the pigment and the quinacridone derivative in a solvent having a strong dissolving power such as sulfuric acid and coprecipitating with a poor solvent such as water.

Further, in the use of the pigment and the quinacridone derivative shown in the above 2 to 4, the pigment or the quinacridone derivative is dispersed in a non-aqueous vehicle or a solvent, and a mixing machine such as a dissolver, a high speed mixer or a homogenizer is used as a dispersion machine. The pigment can be well dispersed by using a mixer, a kneader, a roll mill, a sand mill, an attritor, or the like.

Vehicles used include lime rosin varnish,
There are non-aqueous vehicles such as gravure ink such as polyamide resin varnish or vinyl chloride resin varnish, nitrocellulose lacquer, aminoalkyd resin permanent dry or baking paint, acrylic lacquer, aminoacryl resin baking paint and urethane resin paint.

〔The invention's effect〕

According to the present invention, as compared with the case where the diketopyrrolopyrrole pigment is used alone, it exhibits good fluidity such as a decrease in viscosity of the dispersion and a decrease in structural viscosity, and at the same time, problems such as color separation and crystal change are also caused. In addition, the gloss of the printed matter or the coating film is good, so that a beautiful product can be obtained.

In particular, the quinacridone derivative according to the present invention has an extremely excellent dispersion effect not only in oil-modified aminoalkyd resin paints but also in oil-free alkyd resin paints.

The use of the quinacridone derivative according to the present invention is not limited to the non-aqueous vehicle, and also in the coloring of other printing inks and paints, as well as plastics, a coloring matter having an excellent dispersing effect and a coloring power can be obtained.

Below, an outline of the method for synthesizing the quinacridone derivative according to the present invention is shown as a production example. The following "parts",
"%" Means "parts by weight" and "% by weight", and the number of the quinacridone derivative matches the abbreviation shown in Table-1.

[Production Example 1] The compound represented by the formula (III) was tri (chloromethyl) converted by a conventional method, and 50 parts of the obtained compound was dispersed in 1000 parts of water. Then, 56 parts of diethylamine was added, the temperature was raised to 70 ° C., and the mixture was stirred at the same temperature for 5 hours. The precipitate was filtered, washed with water and dried at 70 ° C. to obtain 58 parts of pigment dispersant (1).

[Production Example 2] The compound represented by the formula [IV] was chloromethylated by a conventional method, and 50 parts of the obtained compound was dispersed in 1000 parts of water. Next, 40 parts of piperidine was added, the temperature was raised to 100 ° C., and the mixture was stirred at the same temperature for 3 hours. The precipitate was filtered, washed with water and dried at 70 ° C. to obtain 54 parts of Pigment Dispersant (8).

The pigment dispersant according to the present invention can be synthesized by the same method as in Production Examples 1 and 2. Some examples are shown in Table 1. In Table 1, "Q1" represents the skeletal structure of the compound represented by formula (III), and "Q2" represents the skeletal structure of the compound represented by formula (IV).

The quinacridone derivative 12 shows a comparative example.

In order to evaluate the dispersion effect of the quinacridone derivative obtained in the present invention, 5% of the quinacridone derivative is added to the diketopyrrolopyrrole pigment represented by the formula (V) below to prepare a paint having the following composition. did.

Formulation (1) Pigment 9.5 parts Pigment dispersant 0.5 part Alkyd resin varnish (nonvolatile content 60%) 26.4 parts Melamine resin varnish (nonvolatile content 50%) 13.6 parts Thinner 20 parts (xylene / n-butanol = 8/2) Mixed varnish added after dispersion 48.3 parts (alkyd / melamine = 7/3 (solid content)) Compounding (2) Pigment 9.5 parts Pigment dispersant 0.5 part Oil-free polyester resin varnish 26.4 parts (nonvolatile content 60%) Melamine resin Varnish (nonvolatile content 50%) 13.6 parts Swazol 20 parts Mixed varnish added after dispersion 48.3 parts (alkyd / melamine = 7/3 (solid content)) Put the above mixture in a container and add a steel ball to paint It was dispersed with a shaker to make a paint. These paints were compared with a paint to which a pigment dispersant was not added (a paint in which the pigment dispersant was not added in the above formulation and the pigment was 10 times larger) according to the following evaluation method. Table 2 shows examples of the results. The numbers of the pigment dispersants in Table 2 correspond to the abbreviations shown in Table 1.

Evaluation method (1) The viscosity of the obtained paint was measured by a B-type viscometer and determined (measuring temperature 25 ° C.). The evaluation was made by a relative comparison with the paint without the pigment dispersant added, and the one having a low viscosity was regarded as good.

◯: Good Δ: Fairly good ×: Poor Evaluation method (2) The obtained paint had a final paint viscosity of 23 for Ford cup 4.
It was adjusted with a thinner so that it would be in seconds, sprayed on a tin plate with an air spray gun, then baked, and visually evaluated the 20 ° gloss with a gloss meter for a comprehensive evaluation of the sharpness of the coated surface.

◯: Excellent Δ: Good ×: Poor When these paints were allowed to stand for 1 week and then measured with the same viscometer, almost no increase in viscosity was observed. In addition, a 1 / 10-cut light-colored paint was prepared using a white paint adjusted with titanium white, the viscosity was adjusted to 23 seconds with a Ford cup 4, and placed in a test tube to observe the aggregation state. No separation or sedimentation was observed.

Furthermore, the pigment to which the pigment dispersant according to the present invention was added showed good dispersibility even in nitrocellulose lacquer, acrylic resin paint and gravure ink without causing aggregation.

Claims (3)

[Claims] 1. A diketopyrrolopyrrole pigment of 100 parts by weight and a quinacridone derivative of the following general formula (I): 0.3
A pigment composition, characterized in that the pigment composition comprises 30 to 30 parts by weight. (In the formula, Q represents a quinacridone residue, n represents an integer of 1 to 10, and R ₃ R ₄ are each independently an optionally substituted saturated or unsaturated alkyl group or aryl group or R ₃ , R ₄ represents an optionally substituted heterocycle containing a nitrogen, oxygen or sulfur atom (except when the heterocycle is a piperazine ring), and P represents an integer of 1 to 4.) 2. The pigment composition according to claim 1, wherein the diketopyrrolopyrrole pigment is one kind or a mixture of two or more kinds of compounds having different structures represented by the formula (II). (In the formula, X represents an oxygen or sulfur atom, A and B may be the same or different from each other, and may be alkyl, aralkyl, cycloalkyl, aryl or carbocyclic or heterocyclic aromatic. Represents a group residue, R ₁ and R ₂ are hydrogen atoms, unsubstituted or substituted alkyl residues,
Further, it represents an alkenyl, alkynyl, aralkyl, cycloalkyl, carbamoyl, alkylcarbamoyl, arylcarbamoyl, alkoxycarbonyl, aryl, alkanoyl or aroyl group. 3. A method for dispersing the diketopyrrolopyrrole pigment in a vehicle, characterized in that 0.3 to 30 parts by weight of the quinacridone derivative according to claim 1 is used for 100 parts by weight of the diketopyrrolopyrrole pigment.