CS267529B1 - Method for Micronizing Azolac C.I. Pigment Red 57: 1 - Google Patents

Abstract

A free suspension of azolac C.I. pigment red 57:1 with a concentration of 50 to 350 g/l was milled in the presence of 6 to 50 g/l of sodium or potassium dialkyl sulfosuccinates, where the alkyl contains 5 to 15 carbon atoms, at a temperature of 15 to 60°C and at a pH of 7 to 9.5. The product is suitable for the pigmentation of gravure printing inks.

Description

DESCRIPTION OF THE INVENTION

TO THE AUTHOR'S CERTIFICATE

FEDERAL OFFICE FOR INVENTIONS

CS 267529 01

The invention relates to a process for micronizing an azolak having the structure (1).

and the product of this type is suitable for plowing to the final form intended for the pigmentation of gravure inks.

Pigments intended for the production of gravure inks must have a high color strength. An increase in color strength can be achieved by reducing the pigment / nicronization particles to a mean primary particle size of about 0.05 .mu.m.

After micronization, the pigments are further treated with various excipients to prevent reagregation of the high surface energy particles. However, this further processing is fundamentally influenced by the micronization process, but in particular by the surfactants which are used in the micronization to facilitate the micronization process. The basic requirement is that the surfactants used do not adversely affect the further surface treatment of the pigment particles and the application properties of the final product. If these side effects occur, the surfactants must be removed after micronization.

Research has now found that micronization of C.I. Pigment Red 57: 1 of formula I can be carried out by grinding an aqueous suspension of azolac with a concentration of 50 to 350 g / l of pigment in the presence of 6 to 50 g / l of a compound of general formula

H ₂ C - COOR

HC - COOR _{/ η /}

SOjM wherein R is a linear or branched aliphatic radical having 5 to 15 carbon atoms, M is Na or K, at a temperature of 15 to 60 ° C and at a pH of 7 to 9.5. This method of micronization consists mainly in the use of a compound of general formula III, which facilitates the micronization of the pigment particles of formula (I), does not have to be removed from the mixture before the pigment particles are converted to oleophilic form and does not impair the application properties of the final product.

According to the present invention, C.I. Pigment Red 57 produced by conventional methods, after synthesis and separation of the pigment, an aqueous suspension containing 50 to 350 g / l of pigment and 6 to 50 g / l of a compound of general formula (11), which may be e.g. sodium dibutylsulfosuccinate, is prepared in a suitable mixer. , sodium diamyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium didecyl sulfosuccinate, sodium tridecyl sulfosuccinate, etc., or potassium salts of the respective compounds may be used. Suspensions containing C.I. Pigment Red 57: 1 and the compound of formula III are ground in vertical or horizontal, continuous or discontinuous bead mills at a temperature of 15 to 60 ° C. In this case, the pigment particles are micronized, i.e. the aggregates are disrupted and the mean size of the primary particles is reduced.

The micronization process of the invention provides C.I. Pigment Red 57.1 of the desired particle size, wherein the micronization product, i.e. an aqueous dispersion containing the pigment and the compound of formula (11), can be used directly for further processing of the pigment, preferably into a final form suitable for gravure inks, e.g. or. osv. No. 265 422. The manufactured products have satisfactory application properties.

The examples illustrate an embodiment of the invention.

Example 1

A slurry containing 0.76 kg of CI Pigment Red 57: 1, 0.090 kg of sodium octylsulfosuccinate and 3.45 kg of water was prepared on the spot. The suspension was micronized in a horizontal KOL Special 0.6 l WABachoven bead mill filled with glass handles with a diameter of 0.7 mm at a peripheral speed of the grinding wheels of 15 ms ^-1 . The mean size of the primary pigment particles after the first pass through the mill Ο, Οό ^ Αΐη, after the second pass was 0.04 _/ Am.

After micronization, the dispersion was processed according to MS. or. osv. No. 265 422 for the final form intended for the pigmentation of gravure inks:

A solution of 0.114 kg of stearic acid monoethanolamide in 0.5 kg of ethanol was added to the dispersion with stirring. The mixture was heated to 80 ° C, acidified with hydrochloric acid to pH 6 and stirred for 60 minutes. The product was then filtered off, washed with water and dried at 90 ° C.

The resulting pigment preparation was evaluated in gravure ink. During the production of the ink, the product was easily dispersed and the test prints had satisfactory parameters. '’

Example 2

1.2 kg of azolac C.I. Pigment Red 57: 1 suspended in 12 l of water containing 0.24 kg of dihexyls 1 sodium succinate. After 2 passes of the suspension through the mill, a pigment dispersion with a mean particle size of 0.052 [mu] m was obtained. The dispersion was processed in a manner analogous to Example 1. The product obtained was fully suitable for the preparation of gravure ink

Claims (1)

Azolac Micronization Method C.I. Pigment Red 57: 1 formula in an aqueous medium, characterized in that the aqueous azolak suspension of formula (1) with a concentration of 50 to 250 g / l is ground in the presence of 6 to 50 g / l of the compound of formula (11). HjC - COOR - COOR _{/ u /} έθ ₃ Μ where R is a linear or branched aliphatic radical having 5 to 15 carbon atoms, M is Na or K, at a temperature of 15 to 60 ° C and at a pH of 7 to 9.5.