JPH0322910B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a pigment composition that has high gloss, excellent stability over time, and transparency, and is suitable for gravure printing. Conventionally, to improve the abrasion resistance of printed matter, polyethylene waxes are generally added in an amount of 1 to 3% by weight based on the pigment in the ink, but this method improves the abrasion resistance compared to products without additives. However, it has the disadvantage that gloss is significantly reduced, and coloring power and degree of color development are also reduced. In addition, the most effective way to significantly improve the gloss of gravure ink, which is one type of printing ink, is to use a powerful dispersion machine such as a two-roll mill or dough mixer, and mix nitrocellulose or polyamide resin with pigment. In many cases, a processed pigment called a so-called chip is used, which is prepared by kneading the pigment in the presence of a small amount of a plasticizer and an aromatic or resinous solvent. However, the disadvantage of this method is that it requires chipping and ink-forming processes, and the operations are complicated.Especially, the chipping process requires a long time for the powerful kneading process, which increases work and energy costs. There were also problems in that the price was high, and in chipping nitrocellulose, there was a great risk of ignition during kneading. As a way to overcome these drawbacks, the present inventor has conducted intensive research to utilize various surface treatment agents such as organic titanium compounds, silane coupling agents, surfactants, and modified silicone oils for the surface treatment of pigments. By treating the pigment with an appropriate amount of modified silicone oil, we have succeeded in developing a pigment composition that is excellent for use in gravure inks, etc., and has extremely excellent gloss, transparency, and stability over time without reducing its fastness to friction. In other words, higher fatty acid modified silicone oil such as oleic acid and stearic acid is added to the pigment at a ratio of 0.01 to 1.
By weight%, preferably 0.05 to 0.5% by weight, the ink can be made into ink using a dispersing machine such as a normal ball mill or sand mill, resulting in an extremely high gloss equivalent to or higher than that obtained through conventional chips. It was discovered that excellent gravure ink, etc., with good transparency, stability over time, dispersibility, and density can be obtained. The present invention makes it possible to easily and inexpensively produce high-quality pigments that can replace expensive chips, which is extremely advantageous industrially. Pigments used in the present invention include soluble and insoluble azo pigments, condensed azo pigments, phthalocyanine pigments, quinacridone pigments, isoindolinone pigments, perylene/berinone pigments, dioxazine pigments, vat dye pigments, and base pigments. Examples include organic pigments such as color dye 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. The higher fatty acid-modified silicone oil according to the present invention is a silicone oil modified with higher fatty acids such as palmitic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid.
KF910, X-22-800, FX-3935 (modified silicone oil manufactured by Shin-Etsu Scientific Industries), etc. can be used. The higher fatty acid modified silicone oil is used in an amount of 0.01 to 1% by weight based on the pigment. If it is less than 0.01% by weight, the effect of the higher fatty acid-modified silicone oil will be small, and if it exceeds 1% by weight, disadvantages such as a decrease in coloring power and degree of color development and loss of ink suitability will occur. Further, when using normal silicone oil or modified silicone oil other than higher fatty acids instead of higher fatty acid modified silicone oil, it is difficult to obtain a good pigment composition because thickening, color development inhibition, and blocking occur significantly. In the present invention, an example of the method of adding and treating the modified silicone oil is as follows. That is, the method for adding higher fatty acid-modified silicone oil is as it is or diluted with a solvent, and in the presence of a surfactant, while stirring at high speed, water is added little by little to emulsify it, and it is added as an emulsion during the production of pigments. When producing a pigment, for example, in the case of an azo pigment, it may be added to the coupler solution or diazo solution before the coupling reaction, or it may be added to the chiller after the coupling reaction. Practically speaking, it is desirable to add it to the pigment slurry after the reaction. As a treatment method, for example, a pigment thriller containing higher fatty acid denatured silicone oil is heated at 40 to 90℃.
Heat and stir for 0.5 to 1 hour. As mentioned above, one example of the addition and treatment method of the above-mentioned modified silicone oil has been shown, but it is not limited to this, and it can be added, for example, during, during, or after the production of ink or dye. Other additives and the like can be added to the pigment composition of the present invention, if necessary. The pigment composition of the present invention is useful as coating materials for printing inks and paints, and provides coating materials with high gloss, excellent stability over time, and transparency. Furthermore, by applying the pigment composition of the present invention to an aqueous coating material, such as an aqueous gravure ink, an aqueous coating material excellent in stability over time, transparency, hiding power, etc. can be obtained. Next, the present invention will be specifically explained with reference to Examples. In addition, "parts" and "%" in the text are parts by weight.
It shows weight %. Example 1 25.3 parts of 3,3-dichlorobenzidine was tetrazotized by a known method, and this was converted into acetoacetanilide.
A coupling reaction was performed in addition to an aqueous solution containing 35.5 parts of Pigment Yellow to obtain a suspension containing 1263 parts of Pigment Yellow. To this suspension, 10 parts of higher fatty acid modified silicone oil (X-22-800 manufactured by Shin-Etsu Chemical Co., Ltd.) and 2 parts of a nonionic sea surfactant (HLB 14 or higher) were added in advance.
While stirring at high speed, gradually pour in 488 parts of water and add 6.2 parts of a prepared 2% emulsion (0.2% as active ingredient based on the pigment). after that,
After stirring at 40°C for 1 hour, the mixture was filtered and washed with water in a conventional manner, and the resulting water-containing cake was dried at 60-70°C and then ground to obtain 63 parts of the pigment composition of the present invention. Using the obtained pigment composition, an ink was formed and tested as described below. [Example of ink formulation] Fill a porcelain pocket with 100 1/2-inch steel balls and formulation A in Table 1, and disperse for 20 hours (confirm with a tube gauge that the coarse particles are 20μ or less). , Formulation B was added and mixed for an additional hour to obtain a dark ink. In addition, polyethylene wax (PW2010
(manufactured by Toyo Petrolite Co., Ltd.) was added to the pigment at 0.1% and kneaded, and using a pigment composition prepared in the same manner,
An ink was prepared in the same manner as Reference Example 1, and the pigment composition of Reference Example 1 was made into chips using a two-roll mill, and an ink was prepared as Reference Example 2.

【table】

[Table] The dark ink obtained as described above was adjusted under certain conditions and processed using a gravure printing machine.
A sample printed on OPP film is shown below.
Each item was evaluated separately. In addition, the dark ink was stored separately under certain conditions, and its viscosity stability over time was also compared.

[Table] Example 2 19 parts of p-toluidine m-sulfonic acid was diazotized by a known method, and this was converted into beta-oxynaphthoic acid.
After adding 19 parts of an alkaline aqueous solution to carry out a coupling reaction, an aqueous calcium chloride solution was added to form a lake to obtain a suspension containing 142.4 parts of Pigment Red 57. In the same manner as in Example 1, a 2% emulsion 4.2 of higher fatty acid denatured silicone oil prepared in advance was added.
(0.2% in terms of active ingredient based on the pigment) was added to obtain 42.5 parts of a pigment composition which was treated in the same manner. When the obtained pigment composition was tested in the same manner as in Example 1, it was found to be excellent in color development, gloss, transparency, stability over time, etc. Example 3 100 parts of crude copper phthalocyanine blue was dissolved in 1000 parts of concentrated sulfuric acid (concentration 78%), poured into 10000 parts of water, filtered and washed with water, and the resulting water-containing cake was
Finely dispersed in water using a high-speed stirrer, a suspension containing 92 parts of α-type copper phthalocyanine blue was obtained. In the same manner as in Example 1, 2% of higher fatty acid modified silicone oil (KF910 manufactured by Shin-Etsu Chemical Co., Ltd.) prepared in advance was added.
9.2 parts of emulsion (0.2 parts active ingredient equivalent to pigment)
%) and treated in the same manner to obtain 92 parts of a pigment composition. When the obtained pigment composition was tested in the same manner as in the examples, good results were obtained. Example 4 100 parts of crude copper phthalocyanine blue was mixed with 1000 parts of common salt as a grinding agent and 110 parts of polyethylene glycol as a grinding aid in a test kneader.
After grinding at 110℃ for 5 hours, the resulting dough was purified with diluted hydrochloric acid and hot water, and the water-containing cake was finely dispersed in water using a high-speed stirrer to obtain a mixture containing 92 parts of β-type copper phthalocyanine blue. A suspension was obtained. In the same manner as in Example 1, 9.2 parts of a 2% emulsion of higher fatty acid-modified silicone oil prepared in advance (0.2% as an active ingredient based on the pigment) was added and treated in the same manner to obtain 92 parts of a pigment composition. When the obtained pigment composition was tested in the same manner as in Example 1, good results were obtained. Example 5 100 parts of crude copper phthalocyanine green was dissolved in 1000 parts of concentrated sulfuric acid (concentration 98%), poured into 10,000 parts of water, filtered and washed with water, and the resulting water-containing cake was stirred into water using a high-speed stirrer. to obtain a suspension containing 100 parts of copper phthalocyanine green. This suspension was treated in the same manner as in Example 1 to obtain 100 parts of a pigment composition. When the obtained pigment composition was tested in the same manner as in Example 1, good results were obtained. Example 6 A water-containing cake containing 100 parts of a commercially available titanium dioxide pigment was finely dispersed in water using a high-speed stirrer.
In the same manner as in Example 1, 10 parts of a 2% emulsion of higher fatty acid-modified silicone oil prepared in advance (0.2% in terms of active ingredient based on pigment) was added and treated in the same manner.
100 parts of a pigment composition was obtained. When the obtained pigment composition was tested in the same manner as in Example 1, good results were obtained.

Claims (1)

[Scope of Claims] 1. A pigment composition comprising a pigment and a higher fatty acid-modified silicone oil, characterized in that the higher fatty acid-modified silicone oil is used in an amount of 0.01 to 1% by weight based on the pigment. 2. The pigment composition according to claim 1, wherein the pigment is an organic pigment.