CS234629B1 - Method of phthalocyanine pigments preparation - Google Patents

Abstract

Process for producing phthalocyanine pigments with favorable rheological properties for quality printing, so that it the phthalocyanine pigment particles modify monoethanolamine condensate and / or diethanolamine with saturated and / or unsaturated with an aliphatic acid or with mixtures of saturated and / or unsaturated aliphatic acids having carbon numbers 10 to 22, in an amount of 5 to 50 wt. based on pigment, in an aqueous medium at 20 to 98 ° C and at pH 1 to 9. Preparation of phthalocyanine pigment which disperses well in systems used in the production of gravure printing colors.

Description

The invention relates to a process for the preparation of phthalocyanine pigments for preparations which are particularly suitable for application in polygraphy.

Copper phthalocyanine is conventionally produced in a coarse, non-pigmented state, in beta form, with crystals up to 100 µm in size. The particle size of the crude phthalocyanine may be reduced to a pigment size (called micronization) by total or partial dissolution of sulfuric acid and reprecipitated into water, taking your alpha form. Conversion to the alpha form also occurs in dry grinding in the presence of salts as grinding aids. Some of the organic solvent added during grinding will prevent much crystalline transformation (US Pat. 2,556,728; 2,556,730) and the pigment beta form can also be obtained by micro-cutting in kneaders (US Pat. 2,982,666). The pigment beta form is the product of grinding crude phthalocyanine in organic liquids (US Pat. 2,556,726), or in aqueous suspensions (US Pat. 2,816,115; 2,999,862) using, e.g., pearls. optionally in the presence of surfactants (U.S. Pat.

775 149) «By permutoid swelling, the beta modification can be prepared from ailfa-beta mixtures after salt-free milling (US Pat. 3,051,718),

Phthalocyanine pigments with a mean particle size of about 0.05 .mu.m have the best application properties. Such fine particles have high free surface energy and are therefore thermodynamically unstable. The tendency to reduce free surface energy begins to show during micronization and especially during drying and storage of the products, resulting in the formation of secondary aggregates, agglomerates (Ber. Bunsenges. Physik, Chem., 71, 239/1967). (J. Oil, Col. Chem. Assocn, 52, 289 (1969)).

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The existence of aggregates and agglomerates impairs the dispersibility of pigments in printing and varnishing systems, and as a result, the pigment dyeing properties of printing, varnishing and polymer films are not fully utilized. The stabilization of the primary pigment particles after micronization, i.e. suppression or reduction of the aggregation (agglomeration) of the particles, is therefore an urgent requirement that leads to lower energy consumption in the redispersion of the pigment in the application environment.

These issues are constantly addressed, as evidenced by a number of drinkers regarding treatments for organic (phthalocyanine) pigments consisting, inter alia, of additives that reduce the aggregation (agglomeration) of pigment crystals during pigment production and which have an affinity for a given delivery system (JAaint Tech. 2 (1970) Pigment Suppl. Xiii (Sept.); British Ink Maker 1, 213 (1971)} J. Appl. Chem. Biotech 26, 55 (1976). abietic acid compounds (British Pat. 1 100 103; 900 757; 978 242; Jap. Pat. 51-54 620), salts of aliphatic acids (US Pat. 2 305 379) aliphatic amines (Jap. Pat. 45-20991; 46-32343; 48-1821), optionally oxethylated (US 3775 149), etc. Stabilization of primary particles of phthalocyanine pigments during micronization by grinding eg in an aqueous suspension is not a simple process, since reducing the particle size of the pigment leads to adverse changes The viscosity of the suspension can be reduced, for example, by the use of a larger amount of surfactants, which, however, if they remain in the product after further processing, result in a reduction in color strength, and further difficulties may arise during product drying / monitoring. ignition/. As already mentioned, these auxiliaries must have affinitulsap. environment. Existing methods of treatment of phthalocyanine pigments, carried out using surfactants during their production, make it possible to produce products which are suitable for less demanding processing in the printing and painting industry, but do not fully meet the strict requirements for pigments intended for example for illustrative purposes. gravure printing. Such pigments (pigment preparations) must have a high color strength in printing and in addition they must have

- 3 234 629 printing ink prescribed flow properties, which are also determined by the pigment used. Inadequate rheological properties of the ink result in reduced ink transfer in the printing presses and thus deteriorate print quality.

According to the present invention, a modified phthalocyanine beta modification pigment can be produced by a process that does not have the above drawbacks, and the product is suitable for pigmenting inks intended for illustrative gravure printing.

According to the present invention, the phthalocyanine pigment treatment process is characterized in that the phthalocyanine pigment particles are treated with a condensate of monoethanolamine and / or diethanolamine with a saturated and / or unsaturated aliphatic carboxylic acid or a mixture of saturated and / or unsaturated aliphatic carboxylic acids. 10 to 24, in an amount of 5 to 50%, wt. % of condensate based on pigment, in an aqueous medium at a temperature of 20 to 98 ° C and at a pH of 1 to 9.

The phthalocyanine beta modification is used as a raw material for the treatment according to the invention. It has a mean particle size of 0.03 to 0.08, preferably 0.04 to 0.06. This pigment can be produced by micronizing crude or purified copper phthalocyanine eg by grinding in an aqueous suspension or by processes using malaxerts »

Upon reaching the desired particle size, the pigment particles are treated with a compound obtained by condensation of monoethanolamine or diethanolamine with an aliphatic saturated or unsaturated carboxylic acid or a mixture of aliphatic saturated and unsaturated carboxylic acids having a carbon number of 10-22. with lauric, tridecanoic, myristic and / or pentadecanoic, pimitic,. stearic, arachic, bepheenic, oleic, etc. Suitable aliphatic carboxylic acids can also be obtained, for example, by hydrolysis of animal fats or vegetable oils. The condensation of the aliphatic acid or mixture of acids with the mono- or diethanolamine must be carried out under conditions such that the carboxyl group is predominantly reacted with the primary or primary carboxylic acid. the secondary amino group of the alkanolamide or mixture of alkanolamines used. This provides a product which is advantageously useful for treating the phthalocyanine pigments of the invention. τ

The phthalocyanine pigment according to the invention is treated with condensate in an amount of 5 to 50% by weight. to the pigment, the condensate is added to the aqueous pigment suspension of suitable particle size with stirring in the form of a solution, e.g. in methanol, ethanol, acetic acid, *

optionally as an aqueous emulsion, which is prepared by mixing the condensate in water. The emulsification of the condensate in water is facilitated by raising the temperature of the system, optionally by using suitable surfactants. After adding the condensate solution or emulsion to the pigment suspension, it is preferable to heat the mixture to, for example, 70-90 ° C and then acidify with a mineral acid (eg hydrochloric acid) and add 1 to 5. pierce with water.

The product (treated phthalocyanine pigment) is then dried in a suitable type of dryer (spray, vortex, or other).

The phthalocyanine pigment treated by the process of the present invention disperses very well in the systems used to produce gravure inks, without the need for extremely efficient and therefore energy intensive dispersing devices. The obtained intaglio inks have favorable rheological parameters and this together with optimal utilization of the phthalocyanine pigment staining ability leads to a quality printing.

Example 1

In a bead mill, a suspension of 0.4 kg of copper phthalocyanine with a mean particle size of 0.05 m in 2.4 liters of water was prepared. diethanolamide of stearic acid and 0.02 kg of oleic acid diethanolamide in 250 g of glacial acetic acid. The mixture was stirred for 15 minutes and then heated to 90 ° C for 5,234,629 at this temperature for 60 minutes. The suspension was then filtered at 50 ° C, washed with water, dried at 90 ° C and ground.

The treated phthalocyanine pigment disperses well in toluene, and the toluene paste was prepared with an intaglio ink having good rheological properties and containing pigment particles of less than 5 µm. The proofing was of high quality both in terms of shade and density.

Example 2

The same results as in Example 1 can be achieved _? if the ground copper phthalocyanine suspension is treated with the product obtained by condensing the monoethanolamine diethanolamine with a mixture of aliphatic carboxylic acids prepared by hydrolysis. coconut oil, rapeseed oil or animal fats.

Claims (1)

BACKGROUND OF THE INVENTION 234 629 Process for treating phthalocyanine pigments, characterized in that the phthalocyanine pigment particles are treated with a condensate of monoethanolamine and / or diethanolamine and a saturated and / or unsaturated aliphatic acid or with a mixture of saturated and / or unsaturated aliphatic acids having a carbon number of 10 to 22, in an amount of 5 to 50% by weight based on pigment, in an aqueous medium at a temperature of 20 to 20% 98 ° C at pH 1 to 9. Printed by Moravian Printing Works,