JPH0217219B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for dispersing pigments that are suitable for use, particularly excellent in 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, fine particles of pigments, when dispersed in non-aqueous vehicles such as offset inks, gravure inks, and paints, make it difficult to obtain stable dispersions, which has an important impact on manufacturing operations and the value of the resulting products. It is known to cause 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. This may happen. Also, when using a mixture of different pigments,
Phenomena such as color separation due to aggregation or sedimentation may cause color unevenness or a significant decrease in coloring power in the developed product. Furthermore, the surface of the coated film of the color spread may suffer from poor conditions such as reduced gloss and poor leveling. Further, although not directly related to the dispersion of pigments, some organic pigments experience a phenomenon that is accompanied by a change in the crystalline state of the pigments. 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 morphology and shift to a stable state, resulting in a noticeable hue in the developed product. Product value may be impaired due to changes in color, decrease in coloring power, generation of coarse particles, etc. The present inventors have developed an offset ink as described above,
We have conducted studies to solve various problems that occur in non-aqueous vehicles such as gravure inks and paints, and have invented a method for producing pigment compositions that is excellent in practice. That is, the present invention is characterized in that when dispersing the pigment in a non-aqueous vehicle, 1 to 18 parts by weight of a colorless or slightly colored compound represented by the following general formula (1) is used per 100 parts by weight of the pigment. This is a pigment dispersion method. General formula (1) In the formula, Q represents a hydrocarbon aromatic polycyclic compound or a heterocyclic aromatic polycyclic compound. A: When Q is a naphthalene nucleus

[Formula] represents a direct bond when Q is other than a naphthalene nucleus. M: represents one equivalent of a mono- to trivalent cation. n: represents an integer from 1 to 4. When Q is a hydrocarbon aromatic polycyclic compound; X: represents -OH or _-NO2 . Y: mutually independent saturated or unsaturated alkyl group having 1 to 20 carbon atoms, aryl group, halogen atom, -COOR', -NR'R'', -
CONR′R″, −SO ₂ NR′R″, −O−R′, −S
−R′, −CN, −NO ₂ , −NR′COR″, −
NR′SO ₂ R″, where R′ and R″ are hydrogen atoms,
Represents a saturated or unsaturated alkyl group or aryl group having 1 to 20 carbon atoms. l: represents 1. m: represents an integer from 0 to 2. When Q is a heterocyclic aromatic polycyclic compound; −
CONR′R″, −SO ₂ NR′R″, −O−R′, −S
−R′, −CN, −NO ₂ , −NR′COR″, −
NR′SO ₂ R″, where R′ and R″ are hydrogen atoms,
Represents a saturated or unsaturated alkyl group or aryl group having 1 to 20 carbon atoms. l, m: Represent mutually independent integers of 0 to 2. As described above, a number of proposals have been made, mainly using 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 significantly advantageous over compounds derived from pigments (dispersants) in terms of availability of raw materials, purity and yield of products in synthetic reactions, etc. Examples of the aromatic compound represented by Q in the general formula () include hydrocarbon aromatic polycyclic compounds such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, perylene, anthraquinone, indole, thiazole, benzimidazole, quinoline, acridone, phenothiazine,
Examples include heterocyclic aromatic polycyclic compounds such as quinazoline, carbazole, and benzanthrone. The sulfonic acid compound represented by the general formula () can be obtained by sulfonating an aromatic polycyclic compound under various conditions. That is, it is generally obtained by hydrolyzing a chlorosulfonated product obtained by a reaction between an aromatic polycyclic compound and sulfuric acid or oleum, or a reaction between an aromatic polycyclic compound and crosssulfonic acid. In addition, for compounds that are very easily sulfonated, such as naphthalene, anthracene, and phenothiazine, the compound represented by the general formula () can be obtained by relatively mild sulfonation with concentrated sulfuric acid using an organic solvent such as ether as a diluent. Note that the number of sulfon groups substituted in the aromatic polycyclic compound and the substitution positions vary depending on the sulfonation conditions, and are also closely related to the reactivity of the compound, so the conditions are selected depending on the purpose. Further, a metal salt compound represented by the general formula () is obtained by adding an equimolar amount of a powder or aqueous solution of a metal hydrochloride, nitrate, etc. to the slurry of the sulfonic acid compound obtained in the above procedure in water or an organic solvent. After stirring, it is obtained by filtering, washing with water, and drying. In addition, the quaternary ammonium salt compound represented by the general formula () can be prepared by adding an alkylamine or an alkylammonium salt to the slurry of the sulfonic acid compound obtained in the above procedure in water or an organic solvent as it is, or by adding the alkylamine or the alkylammonium salt directly to the slurry of the sulfonic acid compound obtained in the above procedure, It is obtained by adding a solution of an organic solvent, stirring, filtering, washing with water, and drying. Examples of M in the general formula () include hydrogen atom, sodium, potassium, calcium, barium, manganese, nickel, cobalt,
Represents metals such as strontium and ammonium cations shown below. Dimethylammonium, trimethylammonium, diethylammonium, triethylammonium, hydroxyethylammonium, dihydroxyethylammonium, 2-ethylhexylammonium, di-2-ethylhexylammonium, pyridinium, piperidinium, dimethylaminopropylammonium, morpholinium,
Examples include lauryl ammonium, stearyl ammonium, oleyl ammonium, hexylammonium, 1,2-dimethylpropylammonium, butylammonium, isobutylammonium, butoxypropylammonium, decyloxypropylammonium, and the like. In the present invention, the above-mentioned sulfonic acid group (or its metal salt, ammonium salt) introduced into the side chain of an aromatic compound can interact with a cationic moiety in a resin component contained in a vehicle in various application systems. It is thought that the strong affinity contributes to improved pigment dispersion. In the present invention, pigments include soluble and insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, perylene/perinone pigments, dioxazine pigments, vat dye pigments, and basic pigments. Organic pigments such as dye-based pigments and inorganic pigments such as carbon black, titanium oxide, yellow lead, cadmium yellow, cadmium red, red, iron black, zinc white, navy blue, and ultramarine blue can be used. The compound represented by the general formula () according to the present invention is blended into the pigment based on 100 parts by weight of the pigment.
1 to 18 parts by weight is preferred. If it is less than 1 part by weight, the effect of the compound represented by the general formula () cannot be obtained, and even if it is used in an amount greater than 18 parts by weight, the effect of the compound used 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 a pigment and a compound represented by the general formula (). Add and disperse in a non-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. As a method for preparing the pigment composition shown in 1 above,
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, homo mixers, 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 varnishes, polyamide resin varnishes or vinyl chloride resin varnishes, nitrocellulose lacquers, and amino alkyd resins can be air-dried or baked. In non-aqueous vehicles such as paints, acrylic lacquers, aminoacrylic resin baking paints, urethane resin paints, etc., the dispersion exhibits good fluidity such as lower viscosity and lower structural viscosity than when the pigment is used alone. At the same time, there are no problems such as color separation or changes in crystals, and the printed matter or coating film has good gloss, making it possible to obtain beautiful products. An example of a compound represented by the general formula () is shown below. Compound example Compound No. 2-hydroxy-3-naphthoic acid anilide
4'-Sulfonic acid 2-hydroxy-3-naphthoic acid anilide
4'-sulfonic acid lauryl ammonium salt 2-hydroxy-3-naphthoic acid anilide
4'-Sulfonate stearyldimethylammonium salt 6-nitro-acenaphthene-3-sulfonic acid 6-nitro-acenaphthene-3-sulfonate calcium salt 6-nitro-acenaphthene-3-sulfonate stearyltrimethylammonium salt Quinoline-5,8 -Disulfonic acid Strontium salt of quinoline-5,8-disulfonate Quinoline-5,8-disulfonate dilauryltrimethylammonium salt XI 1-Nitro-anthraquinone-5-sulfonate sodium salt XII 1-Nitro-anthraquinone-5-sulfonic acid Barium salt 1-Nitro-anthraquinone-5-sulfonic acid stearyl ammonium salt Acridone-2,6-disulfonic acid Acridone-2,6-disulfonic acid strontium salt Acridone-2,6-disulfonic acid-di-2-ethylhexylammonium salt Acridone -2,6-disulfonic acid-distearyldimethylammonium salt 4-methoxy-phenothiazine-1,5-
Disulfonic acid XI 4-methoxy-phenothiazine-1,5-
Disulfonate calcium salt 4-methoxy-phenothiazine-1,5-
Disulfonic acid dibutoxypropylammonium salt XI 10-hydroxy-3,5,8-pyrene trisulfonic acid XII 10-hydroxy-3,5,8-pyrene trisulfonic acid strontium salt XII 10-hydroxy-3,5, 8-pyrenetrisulfonic acid tridecyloxypropylammonium salt Examples and comparative examples are given below to explain. Note that the No. of each compound shown in Roman numerals corresponds to those shown in the compound examples. Example 1 CIPigment on vinyl chloride varnish for gravure
Yellow 83 was blended so that the pigment content was 10% and dispersed using a sand mill to obtain a pigment dispersion.
(Comparative example) CI compound powder was added to the obtained pigment dispersion.
A gravure ink was prepared by blending Pigment 83 in an amount of 10% by weight and stirring uniformly with a dissolver.The viscosity was measured and compared with the viscosity of the above pigment dispersion (comparative example). The results are shown in Table 1, and the material according to the present invention has excellent fluidity. Furthermore, the printed matter printed with this gravure ink showed excellent effects regarding color clarity, coloring power, and gloss. In addition, CIPigment uses a dispersion obtained by dispersing the compound in vinyl chloride varnish for gravure using a sand mill.
Similar effects were obtained even when the weight ratio of Yellow 83 to the compound was 9:1. Comparative Examples and Examples 2 to 16 Gravure ink test Pigment content is 10% in vinyl chloride varnish for gravure
(25% for inorganic pigments) After dispersing various pigments alone (comparative examples) or dispersing various pigments, various compounds shown in Compounds to XII are added to adjust the gravure ink, and its viscosity is I looked into it. 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] 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) A concentrated xylene dispersion of the compound was also prepared by dispersing the compound in xylene using an attritor. Next, the above pigment dispersion and the xylene dispersion of the compound were mixed uniformly in a dissolver so that the weight ratio of CIPigment Blue 15 and the compound was 9:1 to prepare a paint, the viscosity was measured, and the above pigment dispersion (comparative example) ) and viscosity were compared. The results are shown in Table 2, and the material according to the present invention has excellent fluidity. Further, the same effect can be obtained by adding compound powder to the pigment dispersion in an amount of 10% by weight based on the pigment. Examples 18-40 The pigment content of aminoalkyd resin varnish for baking paints is 6% (25% for inorganic pigments).
%) Dispersing various pigments alone (comparative example) or
After dispersing various pigments, each compound shown in Compound Examples ~ was added to prepare a paint, and its viscosity 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.

[Table] In addition, regarding dispersion stability, we will compare examples with regard 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, adjusted to 20 seconds (25°C) using a food cup No. 4, and poured into a test tube to observe changes in the glass wall. The results are shown in Table 3.

[Table] Example 41 CIPigment on nitrocellulose lacquer
Blue 15 was blended 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, CIPigment
The compound was added to Blue 15 in an amount of 10% by weight and mixed uniformly to prepare a paint.The viscosity was measured and compared with the above pigment dispersion. The results are shown in Table 4, and the one according to the present invention has excellent fluidity. Similar results were obtained even when the dispersing machine used for preparing the above paint was changed from a three-roll dispersion machine to a sand mill. Examples 42-56 CIPigment Blue 15 alone in nitrocellulose lacquer with a pigment content of 5.5% (Comparative Example 1)
Table 4 shows the viscosities of paints prepared by dispersing CIPigment Blue 15 or by adding the compound after dispersing CIPigment Blue15. 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 showed excellent fluidity and excellent results in terms of gloss 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 Orange36 alone (comparative example) or after dispersing CIPigment Orange36, the compound is CIPigment
When comparing the fluidity of paints added to Orange 36 at a ratio of 10/90, the paint according to the present invention showed significantly superior results. Furthermore, even in paints prepared by cutting the above-prepared paints using an aluminum paint base prepared in advance with aminoacrylic paint varnish so that the ratio of pigment to aluminum is 1/5, the paints according to the present invention have a significantly clearer color tone. It showed excellent gloss. Example 58 Urethane paint varnish Disperse CIPigment Yellow95 alone (comparative example) in a urethane paint varnish so that the pigment content is 10%, or after dispersing CIPigment Yellow95, the compound becomes 10/90 of CIPigment Yellow95. When the fluidity of the paints added as described above and the state of the developed paint film were compared, it was found that the paint according to the present invention had excellent fluidity and was also excellent in color tone and gloss of the developed paint film. Example 59 Rosin-modified phenolic resin offset ink After dispersing CIPigment Red53 alone (comparative example) or dispersing CIPigment Red57 in a rosin-modified phenolic resin offset ink varnish, compound XII was added to CIPigment Red57.
Offset inks were prepared by adding XII at a ratio of 15/85, and their fluidity was compared using a parallel plate viscometer, and it was found that the inks according to the present invention showed significantly superior results. In addition, printed matter according to the present invention showed excellent results in terms of color clarity, coloring power, and transparency. Example 60 and Comparative Example CIPigment Yellow 14 with 10% pigment content in polyamide-nitrocellulose mixed varnish for gravure
A pigment dispersion was obtained by dispersing with a paint conditioner. Powder of the compound is added to a portion of the pigment dispersion obtained.
3% by weight based on CIPigment Yellow14
A gravure ink was prepared by mixing the ingredients and stirring with a dissolver. Next, an alkylnaphthalene sulfonic acid sodium salt (Perex NB, trade name of Kao Atlas Co., Ltd.) was added to a portion of the remaining pigment dispersion in the same amount as the compound, and a gravure ink for comparison was prepared in the same manner as described above. The viscosity of the gravure inks of Examples, Comparative Examples, and blank gravure inks containing no dispersant, and the gloss of printed matter printed using each gravure ink were measured. The results are shown in Table 6, and the one of the present invention is superior.

【table】

Claims (1)

[Claims] 1. When dispersing a pigment in a non-aqueous vehicle,
A method for dispersing a pigment, which comprises using 1 to 18 parts by weight of a colorless or slightly colored compound represented by the following general formula (1) per 100 parts by weight of the pigment. General formula (1) In the formula, Q represents a hydrocarbon aromatic polycyclic compound or a heterocyclic aromatic polycyclic compound. A: When Q is a naphthalene nucleus, it represents [Formula], and when Q is other than a naphthalene nucleus, it represents a direct bond. M: represents one equivalent of a mono- to trivalent cation. n: represents an integer from 1 to 4. When Q is a hydrocarbon aromatic polycyclic compound; X: represents -OH or _-NO2 . Y: mutually independent saturated or unsaturated alkyl group having 1 to 20 carbon atoms, aryl group, halogen atom, -COOR', -NR'R'', -
CONR′R″, −SO ₂ NR′R″, −O−R′, −S
−R′, −CN, −NO ₂ , −NR′COR″, −
NR′SO ₂ R″, where R′ and R″ are hydrogen atoms,
Represents a saturated or unsaturated alkyl group or aryl group having 1 to 20 carbon atoms. l: represents 1. m: represents an integer from 0 to 2. When Q is a heterocyclic aromatic polycyclic compound; −
CONR′R″, −SO ₂ NR′R″, −O−R′, −S
−R′, −CN, −NO ₂ , −NR′COR″, −
NR′SO ₂ R″, where R′ and R″ are hydrogen atoms,
Represents a saturated or unsaturated alkyl group or aryl group having 1 to 20 carbon atoms. l, m: Represent mutually independent integers of 0 to 2.