WO1992000355A1

WO1992000355A1 - Pigments based on double-layer hydroxides, process for manufacturing the pigments, and their use

Info

Publication number: WO1992000355A1
Application number: PCT/EP1991/001119
Authority: WO
Inventors: Wolfgang Breuer; Helmut Endres; Günter GEISMAR
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1990-06-26
Filing date: 1991-06-17
Publication date: 1992-01-09
Also published as: DE4020272A1

Abstract

The invention concerns water-insoluble pigments based on double-layer hydroxides and water-soluble dyes, the pigments being obtained by reacting double-layer hydroxides formed in situ and water-soluble anionic dyes. The invention also concerns suitable processes for the production of pigments of this kind for use as the colour medium in washing and cleaning agents, soaps, cosmetics, lacquers, paints, foddstuffs, plastics and other polymers.

Description

Pigments based on double layer hydroxides. Process for their preparation and their use

The present invention relates to water-insoluble pigments based on double-layer hydroxides and water-soluble dyes, a process for their preparation and their use.

Double-layer hydroxides are known in the literature, for example from R. Allmann, "Chimia" 24 (1970), p. 99 ff. Chemically, they are mixed basic hydroxyls of divalent and trivalent metal cations.

Natural and synthetic double-layer hydroxides continuously give off water when heated or calcined. The crystal water is completely removed at 200 ° C., higher temperatures lead to the elimination of water from the hydroxide structure and of carbon dioxide from the carbonate contained as the usual anion. The structures of the double-layer hydroxides are broken down in this process, the X-ray diffraction diagrams show only broad and less characteristic lines for periclase (MgO). Due to the different composition, also with regard to the water content, line broadening and shifting can be explained in the X-ray diffraction diagram.

From approx. 200 ° C, more or less continuously, if present, CO2 and water are split off from the decaying hydroxide layers, with a clearly endothermic peak occurring again in a DTA diagram around 400 ° C (WT Reichle , "Chemtech" (January 1986), page 58). This is reduced with this calcination Bulk weight, the pore volume increases and the specific surface area increases.

If the calcination temperature does not significantly exceed 600 ° C, the processes are reversible: the mixed oxide re-forms the layer connection while absorbing water and anions. At higher temperatures, the unordered mixed oxide finally turns into well crystalline and less reactive products and ultimately into spinel and MgO.

EP-A-0 206 798 describes water-insoluble pigments consisting of a complex of a water-insoluble inorganic substrate with anion-exchanging properties, in particular double-layer hydroxides containing magnesium or aluminum, a water-soluble dye and an anionic amphiphilic material. The amphiphilic material is practically organic fatty acids or their salts, as well as sulfonated organic compounds. Synthetic hydrotalcite is mentioned here as a suitable double-layer hydroxide, for example anionic organic dyes as water-soluble dyes. According to the process described here, water-insoluble pigments of this type are produced by bringing the pre-formed double-layer hydroxide, the dye and the amphiphilic material into contact with one another in a liquid medium, for example water.

In a publication by S. Miyata in "Clays and Clay Minerals", 28, No. 1, pp. 50-56, 1980, physico-chemical properties of synthetic hydrotalcases, which are a typical class of the double layer mentioned Represent hydroxides described. This is how the ChemiSorption of Naphthol Yellow S - depending on the molar ratio of aluminum to magnesium and aluminum - certainly. For this purpose, the previously synthesized hydrotalcite is introduced into an aqueous solution of the dye, the solid is filtered off and the residual amount of the dye is determined in the filtrate.

In contrast, the object of the present invention is to provide new water-insoluble pigments based on double-layer hydroxides and water-soluble dyes, which - compared to those of the prior art - are more stable towards chemical and physical ones Influences as well as a higher occupancy density with such dyes.

The present invention accordingly relates to new water-insoluble pigments based on double-layer hydroxides and water-soluble dyes, which are characterized in that they are obtained by reacting double-layer hydroxides which form in situ and water-soluble anionic dyes in aqueous or water-containing dyes Media, the double-layer hydroxides forming in situ having the general formula (I)

II III [Mι_ _x M _x (0H) ₂ ] A _x . mH ₂ 0 (I)

have wherein

MH for at least one divalent metal cation, M ¹¹¹ for at least one trivalent metal cation, A for the equivalent of an anion of a mono- or polybasic acid, 1/6 <x <1/2 and 0 <m <1.

The pigments according to the invention, which are obtained with double-layer hydroxides which form in situ, are distinguished from those Pigments known from the prior art, which are produced by adsorbing the dyes onto pre-formed double-layer hydroxides, obviously have significant structural differences. Surprisingly, it was found that the stability of the pigments according to the invention in the light-fastness test and with respect to oxidizing agents is significantly greater than in the case of the comparable colored double-layer hydroxide pigments of the prior art. In addition, the way in which the pigments according to the invention are prepared means that they incorporate a substantially larger amount of anionic dyes into the double-layer structure that forms than the known pigments of the prior art. This property is also characterized below as "higher occupancy density" (see the examples). The differences shown above are all the more surprising since it would actually have been assumed that an already pre-formed double-layer hydroxide should impart the same properties to the pigments as a double-layer hydroxide which forms in situ.

A preferred embodiment of the present invention is that in the pigments the divalent metal cation (M ^) is selected from magnesium, calcium, manganese, iron, cobalt, Nik¬ kei, copper, zinc and cadmium, while the trivalent metal cation (^ 111 ) preferably consists of aluminum or chromium, manganese, iron, cobalt and nickel. If - in connection with the explanation of the general formula (I) - there is talk of at least one divalent or trivalent metal cation, this means that in such double layer hydroxides there may be several divalent or trivalent metal cations in addition to each ¬ can be present.

In principle, the anion (A) can also be selected from an abundance of mono- or polybasic acids. Preferred according to the invention Anions include hydroxide, chloride, bromide, iodide, nitrate, chlorate, perchlorate, carbonate, sulfate, thiosulfate, tungstate, chromate and hexacyanoferrate and in principle also a large number of organic anions, for example picrates.

All mentioned variation possibilities of the divalent metal cations, the trivalent metal cations and the anions are known in principle from R. Allmann (loc. Cit.).

Particularly preferred are pigments based on in-situ double-layer hydroxides, which are selected from hydraulic talcite, zinc / aluminum phase, magaldrate and / or pyroaurite.

Hydrotalcite is known to be a natural mineral with the ideal shape1

[Mg ₆ Al ₂ (0H) ₁₆ ] CO ₃ . 4 H ₂ 0,

whose structure is derived from that of brucite [Mg (0H) ₂ ]. The synthesis of hydrotalcite is described, for example, in DE-C-3306822, DE-A-3346943 and DE-A-1592 126.

The choice of water-soluble, anionic dyes is not critical, since in principle all commercially available or synthetic water-soluble anionic dyes are suitable for the production of pigments. An essential prerequisite, however, is the anionic character of the dyes, since neutral or positively charged dyes have only a very low affinity for the double-layer hydroxides mentioned. The lower limit of the water solubility of the usable, water-soluble, anionic dyes is 10 mg / 1. However, water-soluble, organic, anionic dyes are preferred selected from the group of anthraquinone or naphthol dyes. The following dyes may be mentioned as examples (the corresponding Chemical Abstracts register numbers in brackets): Alizarin red S (130-22-3), Nitroso R (525-05-3), Acid Green 41 (4430-16-4) and naphthol yellow S (846-70-8).

For the purposes of the invention, such water-soluble, organic, anionic dyes also include so-called “optical brighteners”, as are usually used in detergent formulations, for example the disodium salt of 4,4'-bis (1,3,5-tri- azinyl- (6) -amino) -stilbene-2,2'-disulfonic acid (= Blankophor ^R BBH, Bayer AG) or 4,4'-distyrylbiphenyl derivatives (= Tinopal ^R CBS-X, Ciba-Geigy AG).

Another object of the present invention is a process for the preparation of the above-mentioned water-insoluble pigments based on double-vision hydroxides and water-soluble dyes. This process is characterized in that double-layer hydroxides which form in situ and water-soluble anionic dyes are reacted with one another in aqueous or water-containing media, the double-layer hydroxides which form in situ having the general formula (I)

II III [Ml-χ M _x (0H) ₂ ] A _x . mH ₂ 0 (I)

have, wherein the definitions given above apply to M ¹¹ , M ¹¹¹ , A, x and m.

According to a first, two possibilities with regard to the in situ forming double-layer hydroxides principle - in the sense of the invention are for carrying out the driving Ve ^r Embodiment of the process according to the invention is based on the corresponding, previously calcined double-layer hydroxides. The calcination of the double-layer hydroxides produces a disordered mixed oxide, the above-mentioned divalent and trivalent metal cations, with elimination of water, the layer structure of the double-layer hydroxides being degraded (see also the literature cited at the beginning). For the purposes of the present invention, such a material is referred to as "previously calcined double-layer hydroxide". According to the invention, preference is given to using, as the previously calcined double-layer hydroxides, those which have previously been calcined at temperatures up to about 600 ° C. When reacting with the anionic dyes in the aqueous media mentioned, the structure of the double-layer hydroxides is formed in situ from this mixed oxide structure.

This first embodiment of the process according to the invention is therefore characterized in that previously calcined double-layer hydroxides of the general formula (I) are used to form the double-layer hydroxides of the general formula (I) in situ. These previously calcined double-layer hydroxides in powder form or in the form of an aqueous slurry, which may also contain polar organic solvents, are brought into contact, preferably with stirring, with a solution of the anionic, organic dyes. The solids content is then separated from the supernatant solution. It is irrelevant here whether a solution of dyes is added to a suspension of the previously calcined double-layer hydroxides or a suspension of the previously calcined double-layer hydroxides is added to a solution of dyes. Measures to separate the Solids content, ie the still moist pigment formed from the supernatant solution, are known in principle to the person skilled in the art. Examples include decanting or filtering.

The second process variant of the present invention consists in that the pigments are prepared by in-situ precipitation (also sometimes referred to as flash or conti precipitation) of the double-layer hydroxides in the presence of the anionic dyes. In this case, the preferably water-soluble salts of metal cations forming double-layer hydroxides are added to an aqueous or water-containing solution of an anionic dye in the desired stoichiometric ratio and the double-layer hydroxides in the presence of the water-soluble anionic dyes by increasing the pH educated. In this process variant, the double layer hydroxides which form in situ are reacted with the anionic dyes during the flash precipitation in the alkaline range, ie at pH values of> 7, preferably in the pH range from 9 to 13. The Adjustment of the aqueous or water-containing medium to the desired pH takes place, for example, by adding the hydroxides of the metal cations mentioned (M ¹¹ ) and (M ¹¹¹ ) or by adding alkali metal hydroxides, such as sodium hydroxide. During the reaction, the suspension which forms is stirred and the solids fraction obtained - as described above - is separated from the supernatant solution. The so-called flash precipitation of double-layer hydroxides is generally described in EP-A-0 207 811.

The second embodiment of the process according to the invention is therefore characterized in that the in-situ formation of the double-layer hydroxides of the general formula (I) is preferred water-soluble salts of the metal cations (M ¹¹ ) and (M ¹¹¹ ) are used, the pH of the aqueous or water-containing medium being adjusted to alkaline values, preferably to pH values in the range from 9 to 13. Suitable water-soluble salts of the metal cations (M ¹¹ ) and (^ I) are in particular the salts of the metal cations mentioned with the anions (A) defined above, but the oxides or hydroxides of these metal cations can also be used according to the invention become.

Preferably water is the solvent, i.e. as an aqueous medium, suitable for the process according to the invention.

However, since the solubility of the water-soluble, anionic dyes can be greatly improved in some cases, in particular by the presence of polar organic solvents, the presence of these solvents is preferred in many cases, so that the pigments are formed in solvent mixtures of water and polar organic solvents, the latter comprising, in particular, short-chain alcohols, preferably methanol, ethanol and / or propanol, and also ketones and here in particular acetone. The mixing ratios of water to organic solvents are generally in the range from 5: 1 to 1: 5, preferably in the range from 1: 3 to 3: 1 and in particular 1: 1.

The temperature of the reaction of the in-situ double layer hydroxides and dyes is not critical. The reaction is preferably carried out at room temperature, although any temperature between the melting point and the boiling point of the solutions is suitable. By applying pressure, the temperature of the solvent can, if appropriate, also be above the normal Boiling point can be increased if this is desirable in special cases for reasons of solubility of the dye.

Following the production of the pigments according to the invention, in a special embodiment these can be hydrophobized according to processes known per se. This is done in particular by adding sodium salts of fatty acids, as is known in principle from EP-A-0 206 798 for the water-insoluble pigments described there.

There are practically no limits to the use of the pigments according to the invention. However, the pigments are preferably used as color carriers in washing, rinsing and cleaning agents, soaps, cosmetics, lacquers, paints, foods, plastics and polymers.

Since, in addition to classic dyes with absorption in the visible light range, it is also possible to use dyes which absorb ultraviolet radiation, for example optical brighteners, it is possible to use the pigments provided according to the invention as carriers for optical brighteners in detergents.

In particular after a subsequent hydrophobization of the pigments obtained, a further improved stability towards light and oxidizing agents can be determined.

It is clear from the examples described below that the pigments prepared according to the invention have significantly better physical stability than comparable pigments known from the literature. To investigate the light fastness, the pigments were triturated with aluminum oxide and thickened with water to form a spreadable paste. After a longer exposure time with a xenon lamp, there are color differences to the non-exposed areas. The pigments according to the invention show a significantly lower brightening than pigments of the prior art.

When the pigments are treated with oxidizing agents, such as hypochlorite solution, there is also a markedly increased color stability of the pigments according to the invention compared to the pure dye solutions, which is the case when such pigments are used in bleach-containing suspensions, for example in liquid detergents -Wording, is of particular advantage.

Examples

The following abbreviations are used in the examples below:

HT = hydrotalcite, cal. HT = calcined hydrotalcite, flash HT = "flash" precipitated hydrotalcite.

If the term "calcined hydrotalcite" is used below, it is generally understood to mean a product which has been produced by heating commercially available hydrotalcite to 500 ° C. in the course of 2 hours (loss of mass approx. 40% by weight). The term "flash-precipitated hydrotalcite" is understood to mean a product which has been prepared by in-situ synthesis of the hydrotalcite from the corresponding metal salts.

Examples 1 to 6 relate to the production of pigments according to the invention on the basis of hydrocatalcite which forms in situ from previously calcined hydrotalcite, and furthermore their coating density with different anionic dyes. Comparative Examples 1 and 2 show corresponding values for pigments not according to the invention which correspond to the prior art.

Examples 7 and 8 relate to the production of pigments according to the invention based on flash-precipitated hydrotalcite and their occupancy density. Examples 9 to 11 show the production of pigments according to the invention on the basis of other double-layer hydroxides which form in situ.

Examples 12 to 14 and comparative example 3 relate to the light fastness and oxidation stability of the invention Pigments, again in comparison to pigments of the prior art. Example 15 shows the coating density of pigments according to the invention when using different solvents and example 16 shows the preparation of hydrophobized pigments according to the invention.

example 1

50 ml of an aqueous dye solution containing 1 g / 1 alizarin red S hydrate were mixed with different amounts of calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically.

Table 1 below shows the residual concentrations of dye obtained in the supernatant solution.

Example 2

50 ml of an aqueous dye solution with 2 g / 1 alizarin red S hydrate were mixed with different amounts of calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically.

Table 2 below shows the data obtained.

Table 2

cal. HT residual conc. Cg / 1] [mg / 1]

Example 3

50 ml of an aqueous dye solution containing 1 g / 1 nitroso-R salt were mixed with different amounts of calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically. Table 3 below shows the data obtained.

Comparative Example 1

50 ml of an aqueous dye solution containing 1 g / 1 alizarin red S hydrate were mixed with different amounts of non-calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time the suspension was filtered or centrifuged and the

Residual dye concentration determined photometrically.

Table 4 below shows the data obtained.

Comparative Example 2

50 ml of an aqueous dye solution containing 1 g / 1 nitroso-R salt were mixed with different amounts of non-calcined hydro talcits and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically.

Table 5 below shows the data obtained.

Table 5

300 mg calcim ^'ertes hydrotalcite was added 150 mL least to a solution of 50 ml Alizarin Red S (CQ = 2 g / 1, the concentration of the dye in the starting solution) and. Water added and stirred at 20 ° C for 30 min. After this time, the residual dye content of 130 mg / l was determined photometrically after filtration. The coverage density is calculated to be 0.86 mmol / g.

X-ray diffraction pattern of the dried product (Cu K _α ):

29 [°] 11.60 23.21 34.94 39.30 46.59 60.77 62.06

d [Ä] 7.62 3.83 2.57 2.29 1.95 1.52 1.49

The deeply colored sample was calcined at 500 ° C for 2 h. A grayish powder remained, which calculated mass loss themselves to 60.6%. The X-ray diffractogram produced showed the lines for calcined hydrotalcite.

X-ray diffraction diagram of the calcined product (Cu K _α ):

2 θ [°] 42.54 62.76

d [Ä] 2.12 1.48

Determination of the occupancy density with nitroso-R salt: 150 mg of calcined hydrotalcite were added to a solution of 50 ml of nitroso-R salt solution (CQ = 1 g / 1) and 100 ml of distilled water and proceeded as described above . The residual dye content was 490 mg / l, the occupancy thus 0.45 mmol / g.

X-ray diffraction pattern of the dried product (Cu K _α ):

2 θ [°] 11.58 23.16 35.06 39.14 48.42 60.62 61.75

d [Ä] 7.64 3.84 2.56 2.30 1.96 1.52 1.49

When heated to 500 ° C, the color of this pigment also disappeared. A white product remained.

Example 5

50 ml of an aqueous dye solution containing 1 g / 1 Acid Green 41 were mixed with different amounts of calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically. Table 6 below shows the data obtained.

Table 6 Dye: Acid Green 41

50 ml of an aqueous dye solution containing 1 g / 1 naphthol yellow S were mixed with different amounts of calcined hydrotalcite and stirred at 20 ° C. for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically.

Table 7 below shows the data obtained.

Table 7 Dye: Naphthol yellow S

The preparation of a pigment according to the invention based on 10 mol flash-precipitated hydrotalcite is described, starting from a solution of 15.4 g Mg (Ü3) ₂ • 6 H ₂ 0 (60 mmol) and 7.5 g A1 (N03) 3rd 9 H 0 in 500 ml of water. The solution mentioned was added with vigorous stirring to an alkaline solution which contained 7.2 g of alizarin sulfonate (= alizarin red S hydrate). This resulted in an intensely colored precipitate. After the addition of the metal salt solution had ended, stirring was continued for 2 h. A concentration of alizarin sulfonate of only 13.6 mg / l was found in the filtered mother liquor. Then the occupancy was calculated to be 1.18 g per g hydrotalcite or 3.29 mmol / g.

Example 8

Analogously to Example 7, the metal salt solution mentioned there, which additionally also contained the alizarin sulfonate (total volume 3 l), added a solution of 30 g of 50% sodium hydroxide solution in 50 ml of water with vigorous stirring. This also resulted in an intensely colored precipitate. A residual color concentration of 135 mg / l was determined photometrically. This resulted in an occupancy density of 1.11 g per g hydrotalcite, or 3.09 nmol / g.

Example 9

Analogously to Example 1, 50 ml of an aqueous dye solution containing 1.0 g / 1 alizarin sulfonate and 300.8 mg of a calcined Zn / Al phase (general formula I = x = 0.18; A = CO3 -) - were prepared Heating a Zn / Al phase to 500 ° C. in the course of 2 hours, loss in mass approx. 40% by weight - and stirring at 20 ° C. for 30 minutes. After this time, the suspension was filtered or centrifuged and the residual dye concentration of 737 mg / 1 was determined. The occupancy density was thus 0.12 mmol / g.

Example 10

Analogously to Example 1, 50 ml of an aqueous dye solution containing 1.0 g / l of alizarin sulfonate with 299.6 mg of calcined magaldrate were used

(Magaldrat = [MgιoAl5 (OH) 3i] (Sθ4) _2. NH ₂ 0) - prepared analogously to Example 9 - mixed and stirred at 20 ° C for 30 min. After this time, the suspension was filtered or centrifuged and the residual dye concentration was determined photometrically to be 784 mg / 1. The occupancy density is calculated to be 0.10 nmol / g.

Example 11

Analogously to Example 1, 5.01 g of calcined pyroaurite (pyroaurite = [Mg5Fe (0H) i6] C03. 4.5 H 0) - prepared analogously to Example 9 - was prepared to a solution with 519.8 mg of alizarin sulfonate in 300 ml of water - given and stirred for 30 min at 20 ° C. After this time, the suspension was filtered and the residual dye concentration was determined photometrically to be 429.6 mg. The occupancy density is 0.05 nmol / g.

Example 12

The pigments according to the invention and comparative samples based on non-calcined hydrotalcite and alizarin sulfonate were ground in a 20% concentration with aluminum oxide and mixed with distilled water to form a spreadable paste. They were then applied to an aluminum oxide film and left to dry at room temperature. In parallel, aqueous dye solutions were spread onto the alumina support as reference samples and also dried. The samples were irradiated with a "sunlight improvisator" in a day / night rhythm. A "Xenotest 150" device, System Cassella, Original Hanau, equipped with a Xenon burner Xe 1500 with the color temperature between 5500 and 6500 ° K prescribed according to DIN 54004 served as the "sunlight improviser".

In the pure dye solutions, the first color differences were evident after 4 hours. After 6 hours, a lightening was observed in the pigments based on non-calcined hydrotalcite, while the pigments according to the invention showed no changes.

The nitroso-R salt pigments of all samples behaved principally in accordance with the alizarin sulfonate examples, but color differences occurred here even with shorter exposure times. In the reference sample (aqueous solution of the dyes), there were still no color differences after 1 h, but significant differences after 3 h detect. With the pigments based on non-calcined hydrotalcite, slight color differences were already noticeable after 1 h and clearly discernible after 3 h.

With the pigments according to the invention, no color differences were visible after 1 hour and only very slight after 3 hours.

Example 13

The pigments according to the invention and comparative samples based on non-calcined hydrotalcite - ie cal.HT and HT + Acid Green 41 and flash HT and HT + alizarin sulfonate - were triturated to a pulp with 20% strength with Al ₂ 03 and a little water and in a thickness of Approx. 1 mm applied to an Al ₂ Ö3 film and air-dried. The samples were then exposed to xenon light (see Example 12). The reflective light intensity was measured in percent against a white standard (Ti0 ₂ , 100%) using a color measuring device.

The pigments according to the invention from the reactions of calcined hydrotalcite or the flash precipitation showed significantly lower reflection values than the comparable samples of the reactions with non-calcined hydrotalcite. A clear trend can therefore be seen: The pigments obtained from the reactions with non-calcined hydrotalcite are less color-stable, since the curves (reflection intensity versus time) generally result in larger gradients. This can be seen as a measure of the brightening and thus of the lower light stability.

Table 8 below shows the reflection data obtained. 24

Table 8

Time dye: Alizarin sulfonate Acid Green 41 HT cal. HT HT flash HT

[min] [%] [%] [%] [%]

0

30

90

150

250

330

Slope / 10 " ³ % h" l 7.39 6.64 9.89 4.69

Example 14

Suspensions were prepared from 75 mg of the pigments mentioned in Example 4 in 25 ml of distilled water, and 2% sodium hypochlorite solution was added. The pigments only became lighter after 1 h; after 1.5 h there was still a slight pink color.

Comparative Example 3

Analogous to Example 14, corresponding suspensions of the pigments from non-calcined hydrotalcite were prepared and the procedure was as above. After 1 h the pigments were already colorless. Example 15

50 ml of an aqueous alizarin sulfonate solution with a concentration of 1 g / l were mixed with 50 ml of methanol, 50 ml of isopropanol and 150 ml of methanol. After each addition of 100 mg of calcined hydrotalcite, the dye concentration in the filtered samples was determined as described above.

Table 9 below shows the data on the occupancy density obtained.

Table 9

Water / methanol occupancy

1: 1 0.35 nmol / g

1: 3 0.26 mmol / g

Water / isopropanol occupancy density

1: 1 0.74 nmol / g

Example 16

Suspensions were prepared from 100 mg of the pigments described in Example 4 in 50 ml of distilled water and a solution of 50 mg of sodium oleate in 50 ml of water was added. After stirring at 20 ° C for 30 min, the solids were filtered off and washed. The solids were resuspended in water and about 1/10 of the amount of liquid was mixed with oil. After the samples had been mixed and separated, the total solids content was suspended in the organic phase.

Claims

Patent claims

1. Water-insoluble pigments based on double-layer hydroxides and water-soluble dyes, characterized in that they are obtained by reacting in-situ-forming double-layer hydroxides and water-soluble anionic dyes in aqueous or water-containing media, the in-situ forming Double layer hydroxides the general formula (I)

II III [Mι_ _x M _x (0H) ₂ ] A _x . mH ₂ 0 (I)

have wherein

M * I for at least one divalent metal cation, ¹ * ¹ for at least one trivalent metal cation,

A for the equivalent of an anion of a single or polybasic

Acid, 1/6 <x <1/2 and 0 m <1.

2. Pigments according to claim 1, characterized in that M ¹¹ aus¬ is selected from Mg, Ca, Mn, Fe, Co, Ni, Cu, Zn and Cd.

3. Pigments according to claim 1, characterized in that M ^{111 is} selected from Al, Cr, Mn, Fe, Co and Ni.

4. Pigments according to claim 1, characterized in that A is selected from Cl-, Br ", J", NO3-, CIO3-, CIO / T, OH ", C03 ² ", S0 ² ~, S ₂ 03 - _f WO42-, Crθ4 - and [Fe (CN) 6] ³ '.

5. Pigments according to Claims 1 to 4, characterized in that the double-layer hydroxides which form in situ are selected from hydrotalcite, Zn / Al phase, magaldrate and / or pyroaurite.

6. Pigments according to claims 1 to 4, characterized in that the water-soluble, anionic dyes are selected from the group of anthraquinone and naphthol dyes and the optical brightener.

7. A process for the preparation of water-insoluble pigments as claimed in claims 1 to 6, characterized in that double-layer hydroxides and water-soluble anionic dyes which form in situ are reacted with one another in aqueous or water-containing media, the double-layer hydroxides which form in situ have general formula (I).

8. A process for the preparation of the pigments according to claim 7, characterized in that previously calcined double-layer hydroxides of the general formula (I) are used for in-situ formation of the double-layer hydroxides.

9. A process for the preparation of the pigments according to claim 7, characterized in that the preferably water-soluble salts of the metal cations (M ¹¹ ) and (M ¹¹¹ ) are used for the in situ formation of the double-layer hydroxides, the pH of the aqueous or water-containing medium to alkaline values, preferably to pH values in the range of 9 to 13.

10. A process for the preparation of the pigments according to claims 7 to 9, characterized in that water or mixtures of water and polar organic solvents, preferably short-chain alcohols, are used as the aqueous or water-containing medium.

11. A process for the preparation of the pigments according to claims 7 to

10, characterized in that one carries out the implementation at room temperature.

12. A method for producing the pigments according to claims 7 to

11, characterized in that these are hydrophobized according to methods known per se, in particular by adding sodium salts of fatty acids.

13. Use of the pigments according to claims 1 to 6 as color carriers in washing, rinsing and cleaning agents, soaps, cosmetics, lacquers, paints, foods, plastics and polymers.

14. Use of the pigments according to claims 1 to 6 as carriers of optical brighteners in detergents.