JPH0134270B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for dispersing pigments with excellent usability, particularly non-aggregation and non-crystallinity. In general, practically useful pigments that exhibit vivid color tones and high tinting power in various coating compositions are composed of fine particles. However, when dispersed in non-aqueous vehicles such as offset inks, gravure inks and paints, the fine particles of pigments make it difficult to obtain stable dispersions, which has a significant impact on manufacturing operations and the value of the resulting products. It is known that this causes various problems. For example, dispersions containing pigments made of fine particles often have a high viscosity, making it difficult to remove the product from the dispersion machine and transport it, and even worse, gelation occurs during storage, making it difficult to use. It may become. Also, when using a mixture of different pigments,
Phenomena such as color separation due to aggregation or sedimentation may result in color unevenness or a significant decrease in coloring power in the developed product. Furthermore, the surface of the paint film of the developed product may suffer from poor conditions such as reduced gloss and poor leveling. Further, although not directly related to pigment dispersion, some organic pigments experience a phenomenon that involves a change in the crystalline state of the pigment. In other words, in non-aqueous vehicles such as offset inks, gravure inks, and paints, pigment crystal particles, which are energetically unstable, change their size and shape and shift to a stable state, resulting in a noticeable hue in the developed product. The commercial value may be impaired due to changes in color, decrease in coloring power, generation of grains, etc. The present inventors have developed an offset ink as described above,
We conducted studies to solve various problems that occur in non-aqueous vehicles such as gravure inks and paints, and invented a method for dispersing pigments that is excellent in practice. That is, the present invention is a pigment dispersion method characterized by using 0.3 to 30 parts by weight of a colorless or slightly colored aromatic compound represented by the following general formula () to 100 parts by weight of the pigment. General formula () In the formula, Q: residue of an aromatic polycyclic compound A: directly bonded or represents a divalent bonding group shown below. -O-, -NR'-, -S-, -
CO, −, −SO ₂ −, −CR′R″−, −SO ₂ NR′−, −
CONR'-, a combination thereof, or a carbon number of 1 to 20 bonded to the above divalent bonding group
saturated or unsaturated alkylene groups (but
The alkylene group does not directly bond to other alkylene groups in the formula), and represents a phenylene group. R′,
R″ represents a hydrogen atom or a saturated or unsaturated alkyl or aryl group having 1 to 20 carbon atoms. R ₁ , R ₂ : Hydrogen atom, each independently having 1 to 20 carbon atoms
represents a saturated or unsaturated alkyl group, aryl group, or a heterocycle containing a nitrogen, oxygen or sulfur atom in R ₁ and R ₂ . X, Y: mutually independent -R', halogen atom, -
OR′, −NR′R″, −COOR′, −NHCOR′, −
NHSOR′, −CONR′R″, −SO ₂ NR′R″, −NR′−
CO−R″, −NO ₂ , −CN, −CF ₃ or −SO ₃ M
(M represents 1 equivalent of a mono- to trivalent cation). R′, R″ are hydrogen atoms or 1 carbon number
~20 saturated or unsaturated alkyl or aryl groups. l, m: Represent mutually independent integers of 0 to 2. n: represents an integer from 1 to 6. p: represents an integer of 1 to 2. As described above, a number of proposals have been made, mainly copper phthalocyanine and quinacridone pigments, for the purpose of improving the non-aggregation properties and crystal stability of pigments. The content can be broadly divided into the following two categories based on technical methods. The first method, as seen in US Pat. No. 3,370,971 and US Pat. No. 2,965,511, involves coating the surface of pigment particles with colorless compounds such as silicon oxide, aluminum oxide and tertiary butylbenzoic acid. The second method, as typified by Japanese Patent Publication No. 41-2466 and US Pat. This method involves mixing the resulting compounds. Compared to the first method, the second method has a significantly greater effect on pigment disaggregation, crystal stability, etc. in a non-aqueous vehicle, and judging from the ease of manufacturing the pigment composition, it is also extremely effective. This is an advantageous method. However, in the second method, since the compound added is derived from a compound having the same chemical structure as the pigment, it has inherent strong coloring, and is subject to significant restrictions when used with pigments of different hues. Therefore, it is necessary to prepare corresponding compounds for each pigment, which is a significant disadvantage in the production of pigment compositions. Although the present invention uses a method classified as the second method, all of the compounds represented by the general formula () according to the present invention are colorless or pale yellow, and pigments of various hues and optional There is no problem with the hue even if the pigment is mixed with a non-aqueous vehicle, and therefore, it is an extremely advantageous method for producing pigment compositions. Effects can be obtained. Furthermore, the present invention is superior to the prior art from the viewpoint of the manufacturing method, particularly synthetic technology. That is, the compound represented by the general formula () is
Compared with compounds (dispersants) derived from pigments, they are significantly advantageous because raw materials are easily available and the purity and yield of products in synthetic reactions are also good. Examples of the residue of the aromatic polycyclic compound represented by Q in the general formula () include naphthalene,
Examples include residues of aromatic polycyclic compounds such as anthracene, phenanthrene, pyrene, chrysene, indole, thiazole, benzimidazole, quinoline, acridone, anthraquinone, phenothiazine, quinazoline, carbazole, benzanthrone, and perylene. The compound represented by the general formula () can be prepared by directly reacting the substituted or unsubstituted aromatic polycyclic compound with an amine component, or by reacting the aromatic polycyclic compound with a functional group that easily reacts with the amine component. It is obtained by reacting with an amine component. Typical amine components introduced into the compound represented by formula () are piperidinomethyl, dimethylaminoethyl, diethylaminoethyl, dimethylaminopropyl, diethylaminopropyl, dibutylaminopropyl, piperidinoethyl, pipecolinoethyl, morpholinoethyl, and piperidinoethyl. Nopropyl, pipecolinopropyl, diethylaminohexyl, diethylaminoethoxypropyl, diethylaminobutyl, dimethylaminoamyl, N/N-methyl-lauryl-aminopropyl, 2-ethylhexylaminoethyl, stearylaminoethyl, oleylaminoethyl, p-dimethylamino Ethylsulfamoyl phenyl, p
-diethylaminoethylsulfamoylphenyl, p-dimethylaminopropylsulfamoylphenyl, p-dimethylaminoethylcarbamoylphenyl, and the like. When the amine component described above is introduced into the side chain as represented by the general formula (), it exhibits strong affinity with anionic moieties such as carboxyl groups of the resin component contained in the vehicle, and is useful in a variety of applications. It is thought that this contributes to improving the dispersibility of pigments. In addition, in the general formula (), R' and R'' represent a saturated or unsaturated alkyl group having 1 to 20 carbon atoms, an aryl group, or a heterocycle containing a nitrogen or sulfur atom in R' and R''. But especially R′,
When R'' is an alkyl group having 1 to 4 carbon atoms, the pigment dispersion effect in various uses becomes extremely good.It is also advantageous because the amino compound used as a raw material can be easily produced.Furthermore, aromatic The compounds include -SO ₂ Cl, -COCl,
Since substituents such as -CH ₂ Cl can be introduced relatively easily, other terminals other than R' and R'' of the amine component are substituted with substituents such as -SO ₂ Cl, -COCl-, -CH ₂ Cl, etc. It is advantageous to use a diamine substituted with an amino group that easily reacts with the pigment. That is, diamine is preferable as the amine component introduced into the compound represented by the general formula (). In the present invention, the pigment is preferably a diamine. and organic pigments such as insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, perylene/perinone pigments, dioxazine pigments, vat dye pigments, and basic dye pigments; Inorganic pigments such as carbon black, titanium oxide, yellow lead, cadmium yellow, cadmium red, begara, iron black, zinc white, navy blue, and ultramarine blue can be used.Compounds represented by the general formula () related to the present invention The formulation for the pigment is, per 100 parts by weight of the pigment,
0.5 to 30 parts by weight is preferred. If it is less than 0.5 parts by weight, the effect of the compound represented by the general formula () cannot be obtained, and even if it is used more than 30 parts by weight, the effect of the compound cannot be obtained. Methods of using the compound represented by the general formula () according to the present invention include the following methods: 1. A pigment composition obtained by pre-mixing the pigment and the compound represented by the general formula () is Add to and disperse in an aqueous vehicle. 2. A pigment and a compound represented by the general formula () are separately added to a non-aqueous vehicle and dispersed. 3. The pigment and the compound represented by the general formula () are previously dispersed separately in a non-aqueous vehicle, and the resulting dispersion is mixed. In this case, the compound represented by the general formula () may be dispersed using only a solvent. 4. A compound represented by the general formula () is added to the dispersion obtained after dispersing the pigment in a non-aqueous vehicle. There are four methods, and any of these methods can achieve the desired effect. The method for preparing the pigment composition shown in 1 above is as follows:
Although the desired effect can be obtained by simply mixing the pigment powder and the powder of the compound represented by the general formula () according to the present invention, mechanical treatment using a kneader, roll, attritor, super mill, various pulverizers, etc. The general formula () according to the present invention can be mixed into a pigment suspension system with water or an organic solvent.
Add a solution containing the compound represented by the general formula () to deposit the compound represented by the general formula () on the pigment surface, or combine the organic pigment and the compound represented by the general formula () in a solvent with strong dissolving power such as sulfuric acid. Even better results can be obtained by performing an intimate mixing method such as dissolving and coprecipitating with a poor solvent such as water. In addition, the pigments shown in 2 to 4 above and the general formula ()
When used with compounds represented by formula (2), dispersion machines such as dissolvers, high-speed mixers, homomixers, and kneaders are used for dispersing pigments or compounds represented by general formula () in non-aqueous vehicles or solvents, and mixing them. , a roll mill, a sand mill, an attritor, etc. can be used to achieve good dispersion of the pigment. Therefore, according to the present invention, offset ink vehicles such as various rosin-modified resins, gravure inks such as lime rosin varnish, polyamide resin varnish or vinyl chloride resin varnish, air-drying or baking paints of nitrocellulose lacquer, amino alkyd resin, etc. In non-aqueous vehicles such as acrylic lacquer, aminoacrylic resin baking paint, urethane resin paint, etc., the dispersion exhibits good fluidity such as lower viscosity and structural viscosity than when the pigment is used alone. There are no problems such as color separation or changes in crystals, and the printed matter or coating has good gloss, making it possible to obtain beautiful products. An outline of the synthesis method for a typical compound represented by the general formula () will be described below as a production example. Production example 1 β-oxynaphthoic acid and equimolar thionyl chloride in benzene are heated and stirred under reflux for 1 hour to synthesize chloride. After the reaction is complete, various amines are added and further heated and stirred under reflux for 1 hour. The following compound was obtained. Production Example 2 2,6-naphthalene dicarboxylic acid was heated and stirred with 2 times the mole of thionyl chloride in benzene under reflux for 1 hour to synthesize a chloride, and after the reaction was completed, it was reacted with various amines to obtain the following compounds. Production example 3 2'-hydroxy-3'-naphthoic acid-2,5-dimethoxy-4-chloro-anilide was added to 10 times its weight.
Stir in 98% sulfuric acid at below 20°C for 1 hour to perform sulfonation. The obtained sulfonated product is per molecule
1.2 sulfonate groups are introduced. When the sulfonation reaction was carried out at 40°C for 1 hour, a compound with 2.1 sulfon groups introduced per molecule was obtained. Each of the obtained sulfonated products was reacted with thionyl chloride to be chlorinated in the same manner as in Production Example 1, and then reacted with an amine to obtain the following compounds. Production example 4 2,6-dimethyl-3-hydroxyquinoline-
4-Carboxylic acid was chlorinated with thionyl chloride in the same manner as in Production Example 1, and then reacted with an amine to obtain the following compound. Production Example 5 Phenothiazine is reacted in 98% sulfuric acid in an equimolar amount of 10 times dioxane solvent to obtain phenothiazine sulfonic acid. A phenothiazine sulfonic acid having 0.9 sulfonic acid groups introduced per molecule of phenothiazine is obtained. The obtained sulfonic acid was chlorinated with thionyl chloride in the same manner as in Production Example 1, and then reacted with an amine to obtain the following compound. Production Example 6 2-acetylamino-6-carboxybenzothiazole was treated in the same manner as in Production Example 1 to synthesize a chloride, and then reacted with an amine to obtain the following compound. Production Example 7 The following compound was obtained by chlorinating 3-phenyl-5-nitroindole-2-carboxylic acid in the same manner as in Production Example 1 and reacting with an amine. Production Example 8 Acridone was reacted with 1.5 times the mole of chlorsulfonic acid in 10 times its weight of concentrated sulfuric acid at 80 to 90°C for 1 hour to obtain acridone chlorsulfonic acid. 1.2 chlorsulfonate groups are introduced per molecule of acridone. Similarly, a compound was obtained in which 1.8 chlorsulfonic groups were introduced per molecule of acridone by reacting with 2.5 times the mole of chlorsulfonic acid. The obtained acridone chlorsulfonic acid was reacted with an amine to obtain the following compound. Production Example 9 Anthraquinone-2-carboxylic acid is chlorinated in the same manner as in Production Example 1 to form a carboxylic acid chloride, and then reacted with an amine to obtain the following compound. Production Example 10 Acenaphthene-5-sulfonic acid was chlorinated in the same manner as in Production Example 1, and then reacted with an amine to obtain the following compound. Production Example 11 Pyrene is stirred with 2.2 times the mole of paraformaldehyde in a mixed solvent of 10 times the weight of concentrated sulfuric acid and chlorosulfonic acid (1:1) at 15° C. or lower for 1 hour to obtain chloromethylpyrene. 1.8 chloromethyl groups are introduced per pyrene molecule. Treatment with amine gave the following compound. Production Example 12 A chloride obtained by chlorinating perylene-3,9-dicarboxylic acid in the same manner as in Production Example 1 was reacted with an amine to obtain the following compound. Production Example 13 10-Hydroxy-3,5,8-pyrene trisulfonic acid is chlorinated in the same manner as in Production Example 1, and then treated with an amine to obtain the following compound. Examples and comparative examples will be described below. In addition, the chemical structure of each compound indicated by Roman numerals corresponds to that shown in the production example. Example 1 CIPigment on vinyl chloride varnish for gravure
Yellow 14 was blended so that the pigment content was 10% and dispersed using a sand mill to obtain a pigment dispersion.
(Comparative example) Powder of compound XI-1 was added to the obtained pigment dispersion.
A gravure ink was prepared by blending to CIPigment Yellow 14 at an internal ratio of 10% by weight and stirring uniformly with a dissolver, and the viscosity was measured and compared with the viscosity of the pigment dispersion (comparative example). The results are shown in Table 1, and the material according to the present invention has excellent fluidity. Furthermore, printing with this gravure ink showed excellent effects regarding the clarity of color tone, coloring power, and gloss of printed matter. Also compounds
CIPigment
Similar effects were obtained even when Yellow 14 and Compound XI-1 were added at a weight ratio of 9:1. Comparative Examples and Examples 2 to 16 Gravure ink test Chloride vinyl varnish for gravure with 10% pigment content
(25% for inorganic pigments) by dispersing various pigments alone (comparative example), or by dispersing various pigments and then adding various compounds shown in Production Examples 1 to 13 to prepare gravure ink. The viscosity of perilla was investigated. The results are shown in Table 1, and the material according to the present invention has excellent fluidity. Furthermore, excellent results were obtained in terms of color clarity, coloring power, and gloss of printed matter printed with the gravure ink.

【table】

[Table] Example 17 Adding C. to aminoalkyd resin varnish for baking paint.
I. Pigment Blue-15 was blended so that the pigment content was 6% by weight and dispersed using a ball mill to obtain a pigment dispersion. (Comparative Example) Compound-1 was also dispersed in xylene using an attritor to prepare a concentrated xylene dispersion of Compound-1. Next, the above pigment dispersion and the xylene dispersion of Compound-1 were mixed with CIPigment Blue-15 and Compound-1.
A paint was prepared by uniformly mixing with a dissolver so that the weight ratio of 1 to 1 was 9:1, the viscosity was measured, and the viscosity was compared with the above pigment dispersion (comparative example). The results are shown in Table 2, and the material according to the present invention has excellent fluidity. The same effect can also be obtained by adding powder of Compound-1 to the pigment dispersion in an amount of 10% by weight relative to the pigment and uniformly mixing with a dissolver. Examples 18-40 The pigment content in the amino alkyd resin varnish for baking paints is 6% (in the case of inorganic pigments,

【table】

[Table] 25%) Paints were prepared using various pigments alone (comparative example) or by dispersing various pigments and then adding each compound shown in Production Examples 1 to 13, and the viscosity thereof was measured. The results are shown in Table 2. The aminoalkyd paints according to Examples had excellent fluidity and crystal stability, and also had excellent color beauty, coloring power, and gloss in the coating film. Furthermore, the storage stability was also excellent with little change in viscosity. In addition, with regard to dispersion stability, we will compare examples with respect to color separation stability, which is a particular problem in applications. A light-colored paint is obtained by cutting the paint shown in the examples in Table 2 using a titanium oxide base paint prepared in advance with aminoalkyd varnish so that the ratio of pigment to titanium oxide is 1/10. The light-colored paint was further diluted with xylene, prepared in a food cup No. 4 for 20 seconds (25°C), poured into a test tube, and observed for changes in the glass wall. The results are shown in Table 3.

【table】

[Table] Example 41 CIPigment 15 was blended with nitrocellulose lacquer so that the pigment content was 5.5% by weight and kneaded using three rolls to obtain a pigment dispersion. (Comparative example) In addition, when preparing a pigment dispersion in the same manner as above, just before finishing kneading with three rolls, compound-2 was added to CIPigment Blue 15 at an amount of 5% by weight and mixed uniformly. A paint was prepared, the viscosity was measured, and the viscosity was compared with that of the pigment dispersion described above. The results are shown in Table 4, and the one according to the present invention has excellent fluidity. Similar results were obtained in the preparation of the above paint even when the disperser used was changed from a three-roll dispersion machine to a sand mill. Examples 42-56 Paints prepared by dispersing CIPigment Red 123 alone (Comparative Example 1) or dispersing CIPigment Red 123 and adding compound-1 to a nitrocellulose lacquer so that the pigment content was 5.5%. The viscosity is shown in Table 4. Similarly, Table 4 shows test results regarding the viscosity on nitrocellulose lacquer of combinations of other pigments and various compounds related to the present invention. In all cases, the composition according to the present invention had excellent fluidity and exhibited excellent results in terms of gloss, sharpness of color tone, and tinting power in the developed coating film. The paints shown in the examples in Table 4 were stored at 50° C. for 3 months, and the viscosity was measured after that, and Table 5 shows the results.

【table】

【table】

[Table] As is clear from the results in Table 5, all the products according to the present invention exhibit excellent storage stability. Example 57 Aminoacrylic baking paint Aminoacrylic baking paint varnish with a pigment content of 6
% of CIPigment Orange 36 alone (comparative example) or CIPigment Orange 36
After dispersing compound-3, CIPigment
When the fluidity of paints added to Orange 36 at a ratio of 10/90 was compared, the paint according to the present invention showed significantly superior results. Furthermore, even in paints prepared by cutting the above-mentioned adjusted paint using an aluminum paint base pre-adjusted with aminoacrylic paint varnish so that the ratio of pigment to aluminum is 1/5, the paint according to the present invention has a significantly clearer color tone. It exhibited excellent gloss. Example 58 Urethane paint varnish CIPigment Yellow 95 alone (comparative example) was dispersed in a urethane paint varnish so that the pigment content was 10%, or after CIPigment Yellow 95 was dispersed, compound XI-1 was added to CIPigment Yellow 95.
When the fluidity and state of the developed color coating film of the paints added at a ratio of 10/90 to the above were compared, the paint according to the present invention was found to have excellent fluidity and excellent color tone and gloss of the developed color coating film.

Claims (1)

[Claims] 1. 0.3 of a colorless or slightly colored aromatic compound represented by the following general formula () per 100 parts by weight of pigment.
A method for dispersing a pigment, characterized in that ~30 parts by weight is used. General formula () In the formula, Q: residue of an aromatic polycyclic compound A: directly bonded or represents a divalent bonding group shown below. -O-, -NR'-, -S-, -
CO−, −SO ₂ −, −CR′R″−−SO ₂ NR′−, −
CONR′− or a combination thereof, or
It represents a phenylene group, which is a saturated or unsaturated alkylene group having 1 to 20 carbon atoms (however, the alkylene group is not directly bonded to other alkylene groups in the formula) bonded to the above divalent bonding group. R′R″ represents a hydrogen atom or a saturated or unsaturated alkyl or aryl group having 1 to 20 carbon atoms. R ₁ R ₂ : Hydrogen atom, each independent saturated or unsaturated alkyl group having 1 to 20 carbon atoms , aryl group, or R ₁ and R ₂ represent a heterocycle containing nitrogen, oxygen or sulfur atoms. X, Y: mutually independent -R', halogen atom, -
OR′, −NR′R″, COOR′, −NHCOR′, −
NHSOR′, −CONR′R″, −SO ₂ NR′R″, −NR′−
CO−R″, −NO ₂ , −CN, −CF ₃ or −SO ₃ M
(M represents 1 equivalent of a mono- to trivalent cation). R′, R″ are hydrogen atoms or 1 carbon number
~20 saturated or unsaturated alkyl or aryl groups. l, m: Represent mutually independent integers of 0 to 2. n: represents an integer from 1 to 6. p: represents an integer of 1 to 2.