DE4024409A1 - Green, turquoise and blue metal phosphate pigment - contains alkali metal and zinc, copper and/or cobalt, used for pigmenting (in)organic medium - Google Patents

Abstract

Green, turquoise and blue metal phosphate pigments (I) are of the formula M(I)M(II)PO4 (I) (where M(I) = K, Na and/or Li; M(II) = xZn, yCu and/or zCO; x, y and z each = 0.00-0.99 with (x + y + z) = 1-100. (I) are prepd. by heating the required amts. of alkali oxides, hydroxides and alkali phosphates or cpds. yielding these on calcination or the individual or mixed pptd., opt. hydrated alkali, Zn, Cu or Co phosphates in gas contg. O2, pref. air at 80-1100, pref. 300-900 deg.C., if necessary with addn. of small amts. of mineralisers to promote crystallisation. Calcination may be repeated, opt. several times, after milling the intermediate, at the same or increasing temp.. USE/ADVANTAGE - (I) are claimed for pigmenting inorganic and/or organic dispersion media. They are useful for colouring building materials, lacquers, dispersion paints, plastics, fibres, paper and ceramics. (I) are temp.-stable and consist of a single system. The type and strength of colour can be varied by varying the amt. of Cu and/or Co added and the tone and strength can be maintained even if pt. of the costly Co is replaced by much cheaper Cu.

Description

Of the phosphate-containing inorganic compounds find the white Zn₃ (PO) ₂ · xH₂O (x = 2-4) and the green CrPO₄ · 3 H₂O as anti-corrosive pigments practical application. For the color range are green, turquoise and blue the phosphate-free inorganic described below Compounds have become technically interesting:

Chrome Oxide α-Cr₂O₃, hexagonal Exkolaitgitter Turquoise to green (Zn, Co) O, hexagonal wurtzite mixed phases cobalt blue (Co, Zn) (Al, Cr) ₂O₄, cubic mixed phases, spinels or their other cubic mixed phases with γ-Al₂O₃ Ultramarine Na₈ [Al₆Si₆O₂₄] S _2-4 , cubic sodalite lattice Prussian blue KFe [Fe (CN) ₆], cubic lattice manganese blue Ba (S, Mn) O₄, rhombic barite Zircon Zr (Si, V) O₄, tetragonal circular mesh

The mentioned green, turquoise and blue pigments are partially no special color purity, high proportions of expensive ones Metal oxides (Co, Zr), low chemical and thermal resistance and are not always physiologically harmless.  

Also, the pigments z. T. only at very high temperatures, under special artificial gas atmospheres or in weeks, to present complicated glowing processes under to handle strict environmental protection measures. Also, the whole color palette is from green to turquoise Blue can not be realized in a single system.

The object of the invention is temperature-stable green, Produce turquoise and blue pigments in a single system, whereby color and color strength by variation of the Amount of coloring copper and / or cobalt ions with the Amount of colorless zinc ions in the alkali phosphate system (K, Na, Li) arise. The object of the invention can also be with preservation of the color tone and the color strength a part of the expensive cobalt by the much cheaper Copper of expensive cobalt by the much cheaper Replace copper. The new inorganic greens, Turquoise and blue pigments are systems of composition M (I) M (II) PO₄, where M (I) = K and / or Na and / or Li and M (II) = x Zn and / or y Cu and / or z Co, where the further condition must be met:

0,00x0,99; 0,00y0,99; 0.00z0.99 and x + y + z = 1.00

The new pigments are prepared so that mixtures the amounts of oxides and / or specified according to the equations Phosphates of K, Na, Li; of Zn, Cu, Co or these during annealing on the air supplying compounds (eg Alkali, ammonium carbonates, nitrates, phosphates, acetates, Formates, hydroxides) in a certain temperature range in oxygen-containing atmosphere, preferably in air, be annealed, and the annealed cooled, as well as on Pigment fineness is crushed.  

To pigment particle size in the interest of desired properties To control, can be a precipitation process for manufacturing the pigments or their starting compounds advantageous his. By choosing the concentration of cationic and anionic components, the type of precipitation, the precipitation and Drying temperature can be z. B. in KM (II) PO₄ system produce water of crystallization or anhydrous phases, which alone by drying or glowing in the desired new pigments can be transferred.

Depending on the content of water-soluble salts, the annealing or precipitated product washed with water, filtered off, be dried and ground. Annealing temperature and on duration of action, as well as the presence of smaller quantities the crystallization promoting mineralizers are from crucial for the properties of the new Green, turquoise and blue pigments. The annealing or drying temperature is between 80 and 1100 ° C, preferably between 300 and 900 ° C. The annealing time usually fluctuates between 0.1 and 10 hours, preferably between 0.5 and 5 hours.

The pigments thus prepared have specific BET surface areas (Brunauer, G.H. Emmet and H. Teller, J. Amer. Chem. Soc. 60, 309 (1938) between 0.01 and 300, preferred between 0.1 and 100 m² / g.

In Tables 1-3 are examples of the preparation of per 5 g of pigment of the specified composition listed. Appropriate quantities of reagent grade starting materials are mixed thoroughly in an agate dish. The Mixture is in a platinum crucible after the specified Annealing program at any temperature 1 hour in the air annealed, carefully ground after cooling and the same Time at the next higher temperature again in the air annealed. The visually judged color of the highest annealed  and pigmented products last table column.

Table 1 contains the data for the at least potassium, Table 2, the at least sodium and Table 3 at least Lithium-containing M (I) M (II) PO₄ pigments. you recognizes that after the qualitative visual assessment all colors of bright green, sea green, bright turquoise, blue-turquoise, light blue, gentian blue, bright blue, bright ultramarine blue to violet blue occur. By Amount change of the non-coloring zinc ion in the new phosphate-containing green, turquoise and blue pigments color intensity and color saturation can be varied in such a way that with decrease of the zinc content, the spectral color density and the color intensity increase. For a given composition The divalent cations (Zn, Cu, Co) can be in To a lesser extent the color by type and quantity ratio of the M (I) cations (K, Na, Li). Generally decreases the quality of pigments in the transition from Li about Na and K too, with the property jump at Change from Li to Na is greatest.

In Table 4 are for variously composed K (Co, Cu, Zn) PO₄ blue pigments which were determined according to DIN 53 234 relative color strengths compiled. The Color intensity of preparation no. 4.1, composition

KCo _0,10 Zn _0,90 PO ₄ ,

is used as comparison standard with 100 specified.

It can be seen, as with a constant cobalt content of 0.10 the Color strength when replacing the colorless zinc by the coloring copper cation of 100 over 220 and 240 on 260 increases when the copper content in the formula increases from 0 over 0.20 and 0.45 to 0.60. A similar Color strength like

KCo _0,10 Cu _0,60 Zn _0,30 PO ₄ (No. 4.4)

Has the copper-free compound

KCo _0.25 Zn _0.75 PO ₄ (No. 4.6)

At a constant cobalt content of 0.25 (item 4.6), the Color strength when replacing the colorless zinc by the coloring copper ion from 262 over 367 to 404 when the copper content in the formula is from 0 to 0.38 0.50 increased (numbers 4.7, 4.8).

The inventively prepared new phosphate-containing Green, turquoise and blue pigments provide new inorganic Pigments dar. At a conventional metal price ratio from cobalt to copper of about 6: 1 results in certain Color series an economic advantage since the Color strength of the pigments merely by increasing the Cu Salary can be significantly increased. (Compare Examples 4.1-4.4 and 4.6-4.8).

The visual color impression of the blue pigments changes At constant cobalt content hardly if the colorless zinc is replaced by the coloring copper.

To the aesthetically most satisfying greenish Blue tone of manganese blue and brilliant gentian blue carry certain preparations of the new pigment class, the enrichment of lying in this color range represent inorganic pigments. The new pigments can be used for coloring building materials, of paints and emulsion paints, to plastic, fiber and paper coloring, as for coloring ceramics.

Hereinafter, in Tables 1-4, the invention explained with examples:  

Table 1

Potassium-containing M (I) M (II) PO₄ pigments

Table 2

Sodium-containing M (I) M (II) PO₄ pigments

Table 3

Lithium-containing M (I) M (II) PO₄ pigments

Table 4

Color intensity of K (Co, Cu, Zn) PO₄ pigments (DIN 53.234)

Claims (3)

1. M (I) M (II) PO₄ green, turquoise and blue pigments with M (I) = K and / or Na and / or Li and M (II) = xZn and / or yCu and / or zCo, where 0.00x0.99 and 0.00y0.99 and 0.00z0.99 with x + y + z = 1.00 mean. 2. A method for producing the mentioned in claim 1 Pigments characterized in that mixtures of according to the formulas required amounts of alkali Oxides, hydroxides, alkali phosphates or these when glowing compounds or on obtained the precipitation crystal water containing or anhydrous single or mixed alkali, Zinc, copper or cobalt phosphates in O₂-containing Gases, preferably in air, at temperatures of 80-1100 ° C, preferably at 300-900 ° C, optionally below Addition of small amounts of the crystallization promoting Mineralizers are heated, the Heating or annealing also several times and after simultaneous Grinding the intermediates at the same or increasing temperature can be performed. 3. Use of the phosphate-containing material prepared according to claim 2 Green, turquoise and blue pigments for coloring inorganic and / or organic Disper sion media.