JPH06192587A - Pigment composition and printing ink - Google Patents

Abstract

(57) [Summary] [Structure] Insoluble azo pigments such as C.I. I. Pigme
A pigment composition containing nt Yellow 14 and an aromatic compound having two or more carboxyl groups that does not undergo a coupling reaction with a diazo component, and a printing ink containing the same. [Effect] A printing ink excellent in sowing resistance can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insoluble azo pigment composition having excellent anti-soiling property and a printing ink.

[0002]

2. Description of the Related Art Conventionally, insoluble azo pigments have been widely used as yellow and red colorants for synthetic resin moldings, paints, printing inks, rubber moldings and the like.

Among these applications, printing inks, particularly gravure printing inks, are used for high-speed printing, so that the viscosity during printing must be low and stable. Further, since a considerable amount of time may elapse between the time the ink is manufactured and the time it is used for printing, it is also necessary that the viscosity does not change over time. The performance related to the viscosity required for such an ink is called "viscosity suitability". In addition, the coating film obtained by printing these inks on paper or film,
It is necessary to have excellent gloss and sharpness, so-called suitability for coating film.

However, when an insoluble azo pigment is used as a colorant in a printing ink, particularly a gravure printing ink, the viscosity of the ink in the ink supply section becomes high during printing at high speed, which causes a phenomenon that good printing cannot be performed. . This phenomenon is called "sowering phenomenon". It is believed that this phenomenon is caused by the printing ink absorbing water in the air during printing. If printing is continued with the ink viscosity high, problems such as unclear color tone and deterioration of gloss and tinting strength become serious problems.

That is, when an insoluble azo pigment is used as a colorant in a printing ink, particularly a gravure printing ink,
It has a good coating suitability such as vivid hue, high gloss, and large tinting strength, but it often causes a "soaring phenomenon" in which the ink thickens during printing, so it is necessary to improve the "soaring suitability" of insoluble azo pigments. , A research theme that has been a long-standing concern.

As a method for improving the sowing property, JP-A-63-6072 discloses a method of treating an azo lake pigment with a polyester resin, but does not describe an insoluble azo pigment.

There is no known literature on a method for improving the sowing property of an insoluble azo pigment, but a pigment composition having improved fluidity and cohesiveness is disclosed in Japanese Examined Patent Publication No. 11026/1985.
JP-A-55-10630 and JP-A-59-30862 are disclosed. However, in all of these publications, a soluble azo pigment component (a diazo component or a coupler component having a water-soluble group such as sulfonic acid or carboxylic acid) is reacted with an insoluble azo pigment component. Since a metal salt is used as a component of the pigment composition, hot water coloration resistance (boil resistance) becomes a problem, and there is no effect in improving sowing property.

[0008]

DISCLOSURE OF THE INVENTION The present invention provides an insoluble azo pigment composition excellent in sowing resistance or a printing ink thereof.

[0009]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in view of such circumstances, as a result, an aromatic compound having two or more carboxyl groups which does not undergo a coupling reaction with an insoluble azo pigment and a diazo component. The inventors have found that the pigment composition containing the compounds and the printing ink thereof have excellent anti-soiling properties, and have completed the present invention. Furthermore, as an unexpected effect, the gravure printing ink using the pigment composition of the present invention has excellent viscosity stability over time, and surprisingly, good printability such as highlight transferability and redissolvability. I also found

That is, the present invention is a pigment composition containing an insoluble azo pigment and an aromatic compound having two or more carboxyl groups which does not undergo a coupling reaction with the diazo component, or the insoluble azo pigment. A printing ink comprising a pigment composition as a component.

Examples of the insoluble azo pigment used in the present invention include C.I. I. Pig
ment Yellow 12, the same 14, the same 17, the same 5
5, the same 83, the same 13, the same 81, the same 134, the same 113,
C. I. Pigment Orange 16 and 1
4, the same 13, the same 63, the same 34, the same 38, the same 15, the same 4
4, C.I. I. Pigment Red 213 and 2
3, the same 31, the same 3, 5, the same 22, and the like, and are typically C.I. I. Pigment Yellow 14, the same 17, the same 83, C.I. I. Pigment Red 21
There are 3 mag. In the present invention, organic and inorganic pigments other than the insoluble azo pigment can be used together for the purpose of adjusting the color of the ink.

The aromatic compound having two or more carboxyl groups which does not undergo a coupling reaction with the diazo component used in the present invention (hereinafter abbreviated as aromatic carboxylic acid) is a lower alkyl group, a halogen atom or a nitro group. Phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, 1,2-, 2, which may be substituted with
3-, 2,5- or 1,8-naphthalic acid and the like can be mentioned.

The metal salts of aromatic carboxylic acids used in the present invention include, for example, aluminum salts, magnesium salts, zinc salts, calcium salts, barium salts, strontium salts, etc., but all carboxylic acids are metal salts. You don't have to.

Among the metal salts of aromatic carboxylic acids,
Aluminum salt of phthalic acid, Calcium salt of phthalic acid,
Aluminum salt of isophthalic acid, strontium salt of isophthalic acid, aluminum salt of terephthalic acid, aluminum salt of trimellitic acid, zinc salt of trimellitic acid, calcium salt of trimellitic acid, magnesium salt of trimellitic acid, of trimellitic acid Barium salt, strontium salt of trimellitic acid, aluminum salt of pyromellitic acid, calcium salt of pyromellitic acid, barium salt of pyromellitic acid, strontium salt of pyromellitic acid, 1,
Aluminum salts of 8-naphthalic acid and 2,3-naphthalic acid are preferred.

The method for producing and using the metal salt of aromatic carboxylic acid used herein is not particularly limited. For example, as a method for converting all carboxylic acids of aromatic carboxylic acids into metal salts, aromatic carboxylic acids can be used. After dispersing the acid in hot water, an alkali is added to the carboxylic acid in an equimolar amount or more, for example, sodium hydroxide or the like to be dissolved, and an aqueous solution is prepared. Is added and stirred, and then PH is adjusted to 2 to 7 to produce a metal salt of aromatic carboxylic acid. These metal salts can be used in the form of a slurry dispersed in water, in the form of a filtered cake washed with water, or in the form of a powder further dried.

The insoluble azo pigment composition of the present invention can be easily produced by mixing the above insoluble azo pigment and the aromatic carboxylic acid or its metal salt in a dry state (dry blending).

A preferred method for producing the insoluble azo pigment composition of the present invention is to add the alkaline aqueous solution of the aromatic carboxylic acid described above to the pigment slurry immediately after the synthesis of the insoluble azo pigment, and then add the aqueous metal salt solution to prepare the insoluble azo pigment. However, the present invention is not limited to this.

The insoluble azo pigment composition of the present invention is usually
The amount of the aromatic carboxylic acid or its metal salt is 0.1 to 50 parts by weight based on 100 parts by weight of the insoluble azo pigment.
Preferably, it is 1 to 100 parts by weight of the insoluble azo pigment.
It contains 10 parts by weight of an aromatic carboxylic acid or a metal salt thereof.

The insoluble azo pigment composition of the present invention is used in paints, inks and the like by dispersing it in a vehicle composed of a resin and a solvent. Especially when it is used in gravure printing inks, it is resistant to sowing. Excellent product of

The aromatic carboxylic acid or its metal salt may be added when the ink is prepared by dispersing the insoluble azo pigment in the vehicle. Furthermore, a printing ink prepared by mixing a printing ink composed of an insoluble azo pigment and a vehicle with an ink in which an aromatic carboxylic acid or a metal salt thereof is dispersed in the vehicle also exhibits good sowing resistance.

Among the vehicle components of the gravure printing ink, the resin includes acrylic resin, nitrocellulose resin, polyamide resin, urethane resin, chlorinated polypropylene resin, chlorinated rubber, vinyl chloride-vinyl acetate copolymer resin, rosin. Examples of the resin include one or more selected from resin series.

The solvent may be at least one solvent selected from aromatic hydrocarbons, esters, ketones, alcohols and the like. Specifically, toluene, xylene,
Ethyl acetate, butyl acetate, methyl butyl ketone, methyl ethyl ketone, isopropyl alcohol, methanol,
Examples include ethanol and a mixture thereof.

[0023]

EXAMPLES The present invention will be described in more detail below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. The parts and% in the examples are based on weight.

Example 1 3,3-Dichlorobenzidine Hydrochloride 35 to 227.7 parts
273.8 parts of hydrochloric acid was added, and then 2000 parts by volume of ice water was added and stirred. Under the condition of 0 ° C. or lower, 341 parts of 30% sodium nitrite aqueous solution is added all at once to form tetrazo. To this, 2 parts of activated carbon is added, and the mixture is stirred for 1 hour and then filtered. Excess nitrous acid is canceled with 10% sulfamic acid to obtain a tetrazo solution. Separately prepare the anilide component. To 3,000 parts by volume of water, 364 parts of acetoacetyl orthotoluide is added and dispersed, and then 492 parts of 25% caustic soda is added and dissolved.
214 parts of 90% acetic acid is added dropwise to synthesize sodium acetate in the system. Adjust PH6 and temperature to 20 ℃. A tetrazo solution is added dropwise to the anilide component to complete the coupling reaction in 3 hours. After stirring the obtained pigment slurry for 30 minutes,
After filtration, the obtained wet cake is re-peptized in 15,000 parts by volume of water and adjusted to PH5 with 25% caustic soda. Next, an aqueous solution of trimellitic acid having 11.2 parts dissolved therein is added. After stirring for 30 minutes, aluminum chloride hexahydrate 12.9
An aqueous solution in which parts are dissolved is added. 25% after stirring for 30 minutes
Adjust to PH5 with caustic soda. After the temperature is raised to 80 ° C. and the temperature is kept for 1 hour, the wet cake of the pigment composition obtained by filtering and washing with water is dried in a gear oven at 100 ° C. for 24 hours. The drying lamp is crushed to obtain a pigment (C.I. Pigment Y).
A yellow powder of the yellow 14) composition was obtained.

Preparation of gravure printing ink Yellow powder pigment 7 parts Urethane resin-based varnish 14 parts Thinner (MEK / toluene / IPA) 26 parts Steel beads 200 parts Weighed in a container, dispersed with a paint conditioner for 30 minutes, and then urethane A resin varnish (9.3 parts) and a thinner (13.7 parts) were added, and the mixture was dispersed for 5 minutes with a paint conditioner. This is a urethane gravure printing ink and is called a raw ink.

Evaluation Method (Sowering Test) The viscosity of the raw ink immediately after preparation was measured by Zahn cup No. It was measured at 3.

Next, 55 parts of the original ink was weighed in another container, 1.2 parts of water was added, and the dispersion was treated for 10 minutes with a paint conditioner, and the viscosity of the ink immediately after the treatment was measured. Then, the water-added ink was allowed to stand at room temperature for 5 days, and the viscosity of the ink after standing was adjusted to Zahn Cup No. It was measured at 3.

The anti-soiling property was evaluated by comparing the viscosity of the original ink with the viscosity of the ink containing water and the viscosity of the ink after 5 days.

Comparative Example 1 A comparative pigment was prepared in the same manner as in Example 1. However,
No treatment with trimellitic acid and aluminum chloride was carried out. An ink was prepared and evaluated using the comparative pigment in the same manner as in Example 1.

Example 2 20 parts of trimellitic acid is added to 300 parts by volume of water at 80 ° C. and dissolved. Next, add 5 parts of aluminum chloride to 100 parts by volume of water.
0 part is dissolved and added dropwise to the trimellitic acid solution. Next, 25% caustic soda is added dropwise to adjust to PH5. After filtering and washing thoroughly with water, a wet cake is obtained and dried in a gear oven at 100 ° C. for 24 hours. The drying lamp was crushed to obtain white powder of aluminum trimellitate.

An insoluble azo pigment composition comprising 6.86 parts of the comparative pigment prepared in Comparative Example 1 and 0.14 part of the above-mentioned aluminum trimellitate was prepared, and the ink was prepared and evaluated in the same manner as in Example 1. Made by way.

Example 3 An insoluble azo pigment composition consisting of 6.86 parts of the comparative pigment prepared in Comparative Example 1 and 0.14 part of trimellitic acid (first-grade reagent) was prepared, and the ink was prepared and evaluated in Examples. It carried out by the method similar to 1.

Comparative Example 2 An insoluble azo pigment composition comprising 6.86 parts of the comparative pigment prepared in Comparative Example 1 and 0.14 part of trimellitic anhydride (primary reagent) was prepared, and the ink was prepared and evaluated. The same procedure as in Example 1 was performed. The trimellitic anhydride has one carboxylic acid and does not correspond to the present invention. Ink viscosity measurement results (seconds) and sowing evaluation results are shown in Table 1.

[0034]

[Table 1] The comparative pigment prepared in Comparative Example 1 is a conventional insoluble azo pigment, but when water is added to the ink, the viscosity becomes high, and after standing for 5 days, the viscosity is remarkably increased and the viscosity cannot be measured. "Soiling resistance" is poor. On the other hand, the inks obtained from the pigment compositions comprising the insoluble azo pigments of Examples 1 and 2 and the aluminum salt of trimellitic acid were
There is no change in viscosity after adding water or after standing for 5 days,
The "soiling resistance" was extremely excellent. The ink obtained from the pigment composition containing the insoluble azo pigment of Example 3 and trimellitic acid had a slightly higher viscosity after standing for 5 days, but the "soiling resistance" was a good result. The ink obtained from a pigment composition of trimellitic anhydride having one carboxylic acid of Comparative Example 2 and an insoluble azo pigment was incapable of measuring viscosity immediately after addition of water, and the "soiling resistance" was poor. .

Examples 4 to 16 and Comparative Examples 3 to
5 In Table 2 below, as other examples, Example 2 and Example 3
The results of evaluation of the soaking resistance of the insoluble azo pigment composition obtained by the same method as described above are shown. Further, as a comparative example, the evaluation results of a pigment composition comprising an aromatic carboxylic acid having one carboxylic acid or a metal salt thereof and an insoluble azo pigment are shown for reference.

[0036]

[Table 2]

[0037]

[Table 3]

Examples 17-21 and Comparative Example 6
[Table 10] Table 3 below shows the results of the sowing resistance test, which was carried out in the same manner as in Example 1 except that only the vehicle of the printing ink was changed. Similarly, Table 3 shows, as a comparative example, the results of the anti-soiling test using the pigment prepared in Comparative Example 1 as a comparative pigment and changing only the vehicle of the printing ink.

[0039]

[Table 4]

Examples 22 to 26 and Comparative Example 1
1 to 15 Table 4 below shows the results of the sowing resistance test conducted by changing the type of the insoluble azo pigment as another example. A commercially available insoluble azo pigment was used as a comparative pigment. As an example, the aluminum trimellitate prepared in Example 2 was mixed with a comparative pigment to obtain an insoluble azo pigment composition, and a sowing resistance test was conducted by the method of Example 1.

[0041]

[Table 5]

[0042]

INDUSTRIAL APPLICABILITY According to the present invention, a pigment composition containing an insoluble azo pigment and an aromatic compound having two or more carboxylic acids which does not undergo a coupling reaction with a diazo component, and a printing ink therefor are resistant to sowing. It has excellent properties. Further, the gravure printing ink using the pigment composition of the present invention has excellent viscosity stability over time, and also has good printability such as highlight transferability and redissolvability.

Claims (7)

[Claims] 1. A pigment composition comprising an insoluble azo pigment and an aromatic compound having two or more carboxyl groups which does not undergo a coupling reaction with a diazo component. 2. A pigment composition containing an insoluble azo pigment and a metal salt of an aromatic compound having two or more carboxyl groups which does not undergo a coupling reaction with a diazo component. 3. The pigment composition according to claim 1, wherein the aromatic compound having two or more carboxyl groups that does not undergo a coupling reaction with the diazo component is a benzene ring or a naphthalene ring. Stuff. 4. The insoluble azo pigment is an acetoacetic acid anilide type azo pigment and a naphthol AS type azo pigment.
~ 3 pigment composition. 5. A printing ink containing a vehicle containing a resin and a solvent and the pigment composition according to any one of claims 1 to 4. 6. The resin contained in the vehicle is an acrylic resin, a nitrocellulose resin, a polyamide resin,
The printing ink according to claim 5, which is one or more resins selected from the group consisting of urethane resins, chlorinated polypropylene resins, chlorinated rubbers, vinyl chloride-vinyl acetate copolymer resins and rosin resins. 7. A printing ink comprising the pigment composition according to any one of claims 1 to 6.