SK280031B6 - Process for preparing bismuth vanadate pigments - Google Patents

Abstract

A process for the preparation of bismuth vanadate pigments and solid solutions based on bismuth vanadate by a) mixing a solution of a bismuth(III) salt containing, if necessary, one or more further metal salts or the mixture thereof with an aqueous solution of a vanadate salt containing, if necessary, a molybdate, tungstenate or sulphate salt or the mixture thereof, and b) subsequently aftertreating the resulting suspension to convert the initially amorphously precipitated particles into crystalline compounds, characterised in that fluoride ions are used during mixing and/or in the course of the subsequent aftertreatment stage.

Description

Technical field

The invention relates to a process for the production of bismuth nitrate pigments as well as color-coated bismuth nitrate pigments.

BACKGROUND OF THE INVENTION

Bismuth nitrate compounds are known compounds and their use as pigments for coloring high molecular weight organic materials is also known.

For example, U.S. Pat. Nos. 4115141 and 4115142 disclose bismuth nitrate as a pigmentation, bright yellow compound with a shade similar to primrose, intended for coloring plastics and varnishes. According to these patents, bismuth nitrate is present completely in monoclinic crystal modification (B-fergusonite). The production of this compound consists in the precipitation of soluble bismuth and vanadium compounds. a gel-like front part which is then converted either into a crystalline, pigmentary form by either a heat treatment at 200-500 ° C or a subsequent water treatment under specified conditions.

U.S. Pat. No. 4455174 are further proposed as yellow pigments of bismuth-nitrate and bismuth-molybdate or bismuth-nitrate and bismuth-tungsten derivatives. These are products which consist of several phases and consist of a bismuth-nitrate phase, as well as a bismuth-molybdate phase and / or a bismuth-tungsten phase.

U.S. Pat. No. 4,316,746 also discloses bismuth-nitrate and bismuth-molybdate pigments as well as bismuth-nitrate and bismuth-tungstate pigments which, in the case of bismuth-nitrate and bismuth-molybdate, form the bismuth-bismuth-like crystalline phase in the crystalline phase.

Other bismuth nitrate pigments are described in U.S. Pat. No. 4752460, wherein solid solutions of bismuth nitrate with a specified proportion of molybdenum and / or tungsten are disclosed.

The bismuth nitrate described herein can be produced in two different ways. One method involves synthesis starting from the necessary metal oxides and is carried out as a solid reaction at elevated temperature (see, for example, U.S. Pat. Nos. 4063956 and 4316746). The necessary metal oxides are mixed together dry and the resulting mixture is then subjected to a heat treatment at 300 to 700 [deg.] C. to form a crystalline, pigmentary form. However, the gel-like bismuth-nitrate derivative, often referred to as the front part, may also be first precipitated and this may be subjected to filtration, washing to remove salt, and drying with the final heat treatment as mentioned above.

The second method described in U.S. Pat. No. 4752460 consists in precipitating a bismuth nitrate pigment from an aqueous solution of a bismuth salt, optionally in the presence of other salts such as an alkali metal salt or a zinc salt, and an aqueous solution of a vanadium salt, optionally in the presence of another salt such as molybdate or tungsten. The front part so produced is then subjected without calcination to an aging and water-phase crystallization process. It is further disclosed in the patent that, in the aging and crystallization stages, a suitable additive, for example chlorides, can be added to direct the crystallization and the particle size formed (see relevant data in column 4, lines 10-12 of this patent).

It has now been found that the use of ions of a certain kind in the degree of pigment precipitation and / or crystallization results in improved properties, in particular higher coloring and improved hiding power, while the use of said chlorides does not lead to such effects.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention to provide a bismuth nitrate compound of formula (I) (Bi, A) (V, D) O ₄ (I) wherein:

A is an alkaline earth metal, zinc or a mixture thereof and D is molybdenum, tungsten or a mixture thereof and the molar ratio A: Bi is between 0.03 and 0.4 and the molar ratio D: V is between 0.01 and 0.3, as well as solid solutions based on them,

(a) mixing with subsequent precipitation of a bismuth salt solution containing an alkaline earth metal salt or zinc salt or a mixture thereof, with an aqueous solution of a vanadium salt optionally containing a molybdenum salt or a tungsten salt, or a mixture thereof in said molar ratios;

b) subsequent crystallization and standing of the particles which precipitated from the obtained suspension initially in amorphous form, consisting in using between 0.1 and 3 mol of fluoride ions per 1 mol of bismuth during the mixing and / or the subsequent crystallization step.

Other metal salts are, for example, alkali metal or zinc salts.

The bismuth nitrate pigments which can be produced by the process according to the invention are, for example, monoclinic bismuth nitrate pigments of the formula BiVO ₄ according to US Pat. 4115141 and 4115142, bismuth nitrate containing a proportion of molybdate or tungsten according to U.S. Pat. 4311746 and 4455174, bismuth nitrate pigments containing determined amounts of barium sulfate according to German published DOS 3004083 or, in particular, the bismuth nitrate compound (see U.S. Pat. No. 4752460) of formula (I).

The compounds of formula (I) are solid solutions and may, depending on the chemical composition, have different crystalline modifications.

The notation (Bi, A) in said general formula (I) is understood to mean that bismuth is presented in the form of a bismuth ion and is partially replaced by a divalent metal cation A. In contrast, vanadium is presented as a pentavalent ion in the form of a vanadium ion and may be partially replaced by a hexavalent metal cation such as molybdate or tungsten or mixtures thereof. When A is an alkaline earth metal, this is, for example, beryllium, magnesium, calcium, strontium and barium, in particular calcium and strontium. D is preferably molybdenum.

The compositions which can be used according to the invention are mixtures consisting of at least one alkaline earth metal and zinc or mixtures of different alkali metals.

Soil mixtures, as well as mixtures of molybdenum and tungsten, in any molar ratios. The preferred molar ratio of A to bismuth is 0.02 to 0.5. The preferred molar ratio D to vanadium is 0.01 to 0.3.

Compounds of formula (I) are preferably produced according to the invention wherein A is calcium or strontium and D is molybdenum or tungsten and wherein the molar ratio of A to bismuth is between 0.03 and 0.4 and the molar ratio of D to vanadium is between 0.01 and 0.3.

Particularly preferred is the preparation of compounds of formula (I) wherein A is calcium, D is molybdenum and the molar ratio of calcium to bismuth is between 0.03 and 0.4 and the molar ratio of molybdenum to vanadium is between 0.01 and 0.3 .

As mentioned above, the process of the invention comprises two steps: a precipitation step and a subsequent treatment step.

For the purpose of precipitation, the necessary starting materials are mixed in the form of solutions in which they are contained in the form of their ions. The precipitated particles (often referred to as the forefront) are in no way pigment-like, amorphous by X-ray, and often gel-like.

In the subsequent processing, the precipitated suspension is further stirred so that the particles pass into the crystalline form and grain growth occurs. It is expedient not to isolate the particles obtained from the precipitation step (e.g. by filtration and washing), but to use them directly in the next step of the process.

The precipitation is carried out by mixing a solution of a bismuth salt, for example in nitric acid or acetic acid, containing, as appropriate, one or more other metal salts, such as an alkaline earth salt or a zinc salt, or a mixture thereof, with an aqueous solution of vanadium salt. molybdate, tungstate, sulfate or a mixture thereof.

The upper limit of the concentration of said reaction solutions is determined by the solubility of the salts used, but it is preferred to use dilute solutions, in particular to better control the progressive mixing of equimolar amounts of the solutions contemplated by the invention. The solutions are conveniently mixed at a temperature of from 10 to 100 ° C, preferably at a temperature of from 20 to 40 ° C.

Bismuth salt solutions can be prepared, for example, by dissolving bismuth nitrate (e.g. pentahydrate, of the formula Bi (NO ₃ ) ₃ .5H ₂ O) in, for example, 1.0 to 4.0-normal nitric acid or acetic acid. Aqueous solutions of vanadate can be made, for example, from an alkali metal vanadate (such as sodium or potassium vanadate, for example sodium metavanadate NaVO ₃ or sodium orthovanadate of the formula Na ₃ VO ₄ ), ammonium vanadate or by dissolving vanadium oxide in a basic solution. As the molybdate, tungstate or sulfate, for example, the corresponding sodium, potassium or ammonium salt is used, or the corresponding oxide is dissolved in a basic solution.

Suitable alkaline earth salts or zinc salts are, for example, the corresponding chlorides, acetates or nitrates or the corresponding oxide is dissolved in an acidic solution.

The precursor precipitation reaction may be carried out batchwise or continuously. Advantageously, the mixing of the solutions is carried out with good stirring, possibly with high turbulence, for example in a jet reactor, in a mixing nozzle, optionally under increased pressure or in a device equipped with a high-speed stirrer. The mixing of the various reaction solutions can also be carried out continuously, by simultaneously adding them, or also batchwise, by submitting one solution and adding another solution or other solutions.

The normality of said acidic and basic solutions is adjusted before mixing, for example, such that the pH of the resulting reaction mixture is between 1 and 6, but is preferably less than 3.

To obtain the compounds of formula (I), the front can also be prepared by mixing an aqueous solution of an alkaline earth salt or zinc salt or a mixture thereof with a molybdate or tungsten solution or a mixture thereof to form a compound of formula ADO ₄ wherein A and D are as defined above. wherein the compound, after aging, optionally at elevated temperature, is mixed simultaneously or sequentially with an aqueous solution of the bismuth salt and an aqueous solution of vanadate to form a compound of the invention. The pH of the various starting solutions is preferably adjusted such that it lies in the acidic region during the addition of these solutions, but is preferably not more than 3.

According to one variant of the precipitation step, the bismuth salt solution and, if desired, other metal salts, for example an alkaline earth or zinc salt or a mixture thereof, and an aqueous solution of vanadate and, if desired, a molybdenum, tungsten or sulfate salt or mixture thereof, can be added simultaneously to water.

After the precipitation step, the front part so produced is subjected to a crystallization and aging process (otherwise referred to as a post-treatment step) in the aqueous phase.

In this case, the suspension obtained from the precipitation step is adjusted by adding an inorganic base to the acidic region, for example to a pH of between 4 and 8.5, preferably between 5 and 7, and further stirring. In this case, it is advantageous if the suspension is gradually heated, for example at a temperature of 50 to 110 ° C, preferably 90 to 95 ° C, during or after increasing the pH. The pH increase can also be carried out successively by stirring, for example, the suspension for a period of time, for example 60 minutes, for example at a pH of 3.5, before raising the pH further. The heating can be carried out, for example, by electrically heating the outside of the reaction boiler or by directly introducing water vapor into the reaction boiler.

Suitable organic bases are, for example, sodium hydroxide or potassium hydroxide, preferably in the form of an aqueous solution.

During the subsequent work-up, the amorphous front of the gel is converted into a brilliant yellow, crystalline compound whose crystallinity is shown to be good according to the powder X-ray diagram. The total time for subsequent processing may vary depending on the size of the batch. Generally, 2 to 5 hours are sufficient to achieve complete crystallization.

In principle, it is possible to introduce fluoride ions, for example as a separate aqueous solution, or to mix it with a bismuth salt solution or a vanadate solution, and then combine the two solutions. However, it is preferred that the fluoride ions be introduced into a vanadate solution. Another possibility is that the fluoride ions contain both a bismuth salt solution and a vanadate solution.

In the process according to the invention, however, it is also possible to admix fluoride ions only in the subsequent treatment step. However, it is also possible to divide the fluoride ion addition into both process steps.

In the process according to the invention, fluoride ions are preferably added in the following treatment.

The amount of fluride ions may vary. Suitably, 0.1 to 3 parts by weight of the molar fluoride salt, based on 1 part by weight of the bismuth, are used, but preferably 0.8 to 3 parts are used.

1.2 parts molar, particularly preferably 1 part molar fluoride salt. Suitable fluoride salts are, for example, alkali metal, alkaline earth metal fluorides and ammonium fluoride, for example NaF, KF and NH ₄ F, in particular sodium fluoride or potassium fluoride, suitably in the form of an aqueous solution.

The treatment of the compounds obtained according to the invention is carried out in a customary manner, for example by filtration, washing the filter cake with water to remove soluble salts, drying and powdering.

In order to improve the pigmenting properties, for example stability to heat, light and chemical deterioration, it is preferable to coat the compounds obtained according to the invention during their production (precipitation and subsequent treatment) or preferably after the described process steps with an inorganic or organic protective coating so that See, e.g., U.S. Pat. 3370971, 3639133 and 4046588. For this purpose, bismuth nitrate pigments are precipitated, for example by treatment with inorganic substances such as aluminum, titanium, antimony, cerium, zirconium or silicon or zinc phosphate compounds or mixtures thereof. This treatment is carried out in one or more stages. Suitably, the amount of coating composition is 2 to 40%, preferably 2 to 20%, and particularly preferably 3 to 10%, based on the total weight of the compound.

To improve these pigmenting properties, the products can be additionally treated with a texture improver, such as long chain aliphatic alcohols, esters, acids or salts thereof, amines, amides, waxes or resin substances such as abietic acid, its hydrotreating agents products, esters or salts, and further with non-ionic, anionic or cationic surfactants.

The products obtained by the process of the present invention can be converted, if desired, by conventional methods, such as those described, for example, in U.S. Patent No. 5,201,549. No. 4762523, for dust-free pigment preparations.

Another object of the present invention is to provide novel, high-color bismuth nitrate pigments of formula I wherein A is an alkaline earth metal, zinc or a mixture thereof, D is molybdenum, tungsten or a mixture thereof and the molar ratio of A to bismuth is between 0.01 and 0. 6 and the molar ratio D to vanadium is between 0 and 0.4, these compounds having a coloring of from 0.045 to 0.130 at a color saturation of 1/25, determined according to DIN 53235.

For the interpretation of the substituents A and the molar ratio of A to bismuth and D to vanadium, the same definitions as described above apply.

The preferred molar ratio of A to bismuth is 0.02 to 0.5. The preferred molar ratio D to vanadium is 0.01 to 0.3.

Preferred are the bismuth nitrate pigments of formula (I) wherein A is calcium, D is molybdenum and the molar ratio of calcium to bismuth is between 0.03 and 0.4 and the molar ratio of molybdenum to vanadium is between 0.01 and 0.3.

The color shade of the coloring bismuth nitrate pigments of the formula (I) obtained by the process according to the invention can be varied, for example, by changing the molar ratio of calcium to bismuth and / or molybdenum to vanadium, and also by changing the pH before or during heating at stage subsequent processing so that pigments having a yellow hue to green or a yellow hue to red can be obtained.

The bismuth-nitrate pigments of formula (I) have in most cases a square crystallographic structure similar to scheelite.

The characterization of the square crystallographic structure follows from the X-ray powder image. Although of course it takes into account the overall diagram, in particular, as an illustration is shown within the area of the diffraction planes of about 0.26 m ^"9th Bismuth vanadate in a stable B-fergusonitovej structure having monoclinic symmetry, comprising two approximately equal intensity lines at d equal to 254.6 and 259.8 m ^"12th A scheelite-like square structure has only one line with a d value of 0.258m ' ⁹ .

Color is expressed by the ratio of the color pigment used in the lacquer to the white pigment (titanium dioxide), which leads to a standard color saturation of 1/25, as determined by DIN 53235. This ratio also indicates the amount of color pigment (in this case of the invention) which, when mixed with said amount of white pigment, allows the production of a lacquer dye with a standard dye saturation of 1/25.

The coloring bismuth nitrate pigments described above can be produced according to the method already mentioned.

The bismuth nitrate pigments obtained by the process of the present invention have good pigmenting properties and are excellent for pigmenting high molecular weight organic materials.

The high molecular weight organic materials to be stained may be of natural or artificial origin. They may be, for example, natural resins or drying oils, rubber or casein, or modified natural substances such as chlorine rubber, oil-treated alkyd resin, viscose, o cellulose ethers or esters such as cellulose acetate, cellulose propionate, cellulose acetobutyrate, nitrocellulose, but above all they are total synthetic organic polymers (thermosets and thermoplastics) which are obtained by polycondensation polymerization or polyaddition. In particular, polyolefins such as polyethylene, polypropylene or polyisobutylene, further substituted polyolefins such as a polymer obtained from vinyl chloride, vinyl acetate, styrene, acrylonitrile, acrylic acid esters and / or methacrylic acid or butadiene copolymers as well as copolymers may also be mentioned from the group of polymers. especially ABS-alkylate-butadiene-styrene or EVA-ethylene-vinyl acetate. Among the polyaddition and polycondensation resins, mention should be made of formaldehyde-phenol condensation products referred to as phenolplastics, and formaldehyde condensation products with urea, thiourea and melamine, referred to as aminoplasts, and polyesters used as lacquer resins as unsaturated, such as maleic resin and linear polyesters, polyamides, polycarbonates and polyphenylene oxides or silicones. Said high molecular weight compounds may be singly or in mixtures, such as plastics or melt, which may optionally be fiberized. The compounds may also be in dissolved form, such as film-forming or binding agents for lacquers, paints or printing inks, such as linseed, nitrocellulose, alkyd resins, melamine resins and urea-formaldehyde resins and acrylic resins.

The pigmentation of the high molecular weight organic substances by the compounds obtained according to the invention is carried out, for example, by admixing such a compound, optionally in the form of a premixture thereof, using a roller or a mixing or grinding device. The pigmentary material is used herein in a conventional manner, for example, on a cauldron, press, extruder, coating, coating or injection molding in the desired form applied at the end of production. It is often desirable not to present solid moldings during manufacture or to add so-called plasticizers to the high molecular weight compounds prior to molding to reduce their brittleness. For example, phosphoric acid, phthalic acid or sebacic acid esters may serve as such agents. The plasticizers can be incorporated into the polymer before or after the introduction of the compounds obtained according to the invention.

In addition, in order to achieve different color tones of high molecular weight organic compounds, in addition to the compounds obtained according to the invention, fillers or other color components such as white, color or black pigments may be added in any amount.

For pigmentation of lacquers, paints or printing inks, high molecular weight organic materials and bismuth nitrate pigments, optionally together with additives such as fillers, other pigments, desiccants or emollients, are finely dispersed or dissolved together in an organic solvent or mixture of organic solvents. In this case, it is possible to disperse or dissolve the individual components themselves, or to disperse or dissolve them more skillfully, and then to combine all the components.

The bismuth nitrate pigments which can be produced according to the invention can be added to the high molecular weight organic materials in an amount of from 0.001 to 70% by weight, in particular from 0.01 to 35% by weight.

Preferred fields of application are paints for industry and vehicles intended for the production of lead-free, brilliant, uniform weather-resistant color shades as well as blending with other pigments to achieve the specified color shades.

The compounds obtainable according to the invention, incorporated into plastics, fibers, lacquers, paints or printing inks, are generally characterized by good pigmentation properties, such as good dispersibility, high dyeing, purity, high hiding power, good fastness properties. coating, migration, heat, light and weather conditions as well as good stability to chemicals such as acids, bases, organic solvents and industrial atmosphere, and above all have high coloring and high hiding power. In addition, the inks, paints and varnishes produced therefrom have good theological properties and impart a good gloss to the dried film.

The percentages in the examples below are percent by weight. The composition of the compounds is given by elemental analysis and the molar ratios of A to bismuth and D to vanadium, which are calculated from elemental analyzes. The bismuth trioxide content is calculated from the remaining, directly determined contents.

DETAILED DESCRIPTION OF THE INVENTION

Example 1 (Bi, Ca) (V, Mo) O ₄

Dissolve 97.0 g of bismuth nitrate pentahydrate, 11.8 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 12.1 g of sodium molybdate dihydrate, 4.7 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to pH 3.5 with 30% sodium hydroxide solution. Finally, the suspension is stirred at this pH for one hour at room temperature. Subsequently, the pH is adjusted to 6.5 over one hour by slowly adding 1N sodium hydroxide solution. Thereafter, the suspension is heated to reflux, maintaining the pH of the suspension at 6.5 by further adding 1N sodium hydroxide solution (for example using an appropriate pH maintaining device). The pH of 6.5 is kept constant until the suspension begins to turn yellow and the pH begins to rise spontaneously. The pigment slurry is then stirred for an additional hour at reflux, raising the pH to approximately 8.5, then filtered, and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 71 g of a bright yellow pigment are obtained in the form of a powder with the following elemental analysis results:

4.9% Ca, 11.7% V, 1.5% Mo.

The results of elemental analysis point to the following molar ratios: calcium to bismuth = 0.40 molybdenum to vanadium = 0.07.

The X-ray diagram shows a square structure.

Example 2 (Bi, Ca) (V, Mo) O ₄

The procedure is as in Example 1 except that the following amount of substance is heated:

97.0 g of bismuth nitrate pentahydrate, 2.95 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid in 600 ml of water,

28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water.

The pH is adjusted to 5.9 before heating and kept constant during heating. 69 g of a pigment are obtained in the form of a powder with the following elemental analysis results:

3.4% Ca, 11.8% V, 0.5% Mo.

The results of elemental analysis point to the following molar ratios: calcium to bismuth = 0.31 molybdenum to vanadium = 0.02.

Example 3 (Bi, Ca) (V, Mo) 0 ₄

Variation of the molar ratio of calcium to bismuth and molybdenum to vanadium

Dissolve 97.0 g of bismuth nitrate pentahydrate, 7.2 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 7.6 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to pH 3.5 with 30% sodium hydroxide solution. The suspension is then stirred at this pH for one hour at room temperature. Subsequently, the pH is raised to 6.0 over one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension at 6.0 by the further addition of 1N sodium hydroxide solution, for example by means of an appropriate pH maintaining device. The pH of 6.0 is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry was then stirred for one hour at reflux, increasing the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension obtained is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 71 g of a bright yellow pigment is obtained in the form of a powder having the following elemental analysis results:

4.1% Ca, 17.3% V, 3.5% Mo.

The results of elemental analysis show the following molar ratios: calcium to bismuth = 0.36 molybdenum to vanadium = 0.11.

Example 4 (Bi, Mg) (V, Mo) O ₄

Use of magnesium nitrate instead of calcium nitrate

Dissolve 97.0 g of bismuth nitrate pentahydrate, 3.1 g of magnesium nitrate hexahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension obtained is approximately 0.9 and is adjusted to pH 3.5 with 30% sodium hydroxide solution. The suspension is then stirred at this pH for one hour at room temperature. The pH is further raised to 6.0 within 1 hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension at 6.0 by further addition of 1N sodium hydroxide solution (for example, using an appropriate pH-maintaining device). The pH of 6.0 was kept constant until the suspension began to turn yellow and the pH rose spontaneously. The pigment slurry was then stirred for one hour at reflux, whereupon the pH rose to about 8.5. In order to achieve an incomplete passage of vanadate into solution, the pH is adjusted to 9.8 and the suspension is finally filtered. The filter cake is washed to remove salts and dried in an oven at 90 ° C. 69 g of a bright yellow pigment is obtained in the form of a powder having the following elemental analysis results:

0.3% Mg, 16.8% V, 1.6% Mo.

The results of elementary analysis point to the following molar ratios:

magnesium to bismuth = 0.04 molybdenum to vanadium = 0.05.

Example 5 (Bi, Sr) (V, Mo) O ₄ Use of strontium nitrate in place of calcium nitrate

Dissolve 97.0 g of bismuth nitrate pentahydrate, 2.6 g of strontium nitrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to pH 3.5 with 30% sodium hydroxide solution. The suspension is then stirred at this pH for one hour at room temperature. The pH is then raised to 6.0 over one hour by slowly adding 1N sodium hydroxide solution. The suspension is heated to reflux, maintaining the pH of the suspension at 6.0 by further adding 1N sodium hydroxide solution (for example, using an appropriate pH maintaining device). The pH of 6.0 was kept constant until the suspension became yellow and the pH rose spontaneously. The pigment slurry was then stirred for one hour at reflux, increasing the pH to about 8.5. To achieve incomplete passage of vanadate into solution, the pH is adjusted to 9.8, the suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69g of a bright yellow pigment is obtained, which has the following elemental analysis results:

2.2% Sr, 18.8% V, 1.2% Mo. The pigment is in powder form.

The results of elementary analysis 'point to the following molar ratios':

strontium to bismuth = 0.09 molybdenum to vanadium = 0.03.

Example 6 (Bi, Zn) (V, Mo) O ₄ Use of zinc nitrate instead of calcium nitrate

Dissolve 97.0 g of bismuth nitrate pentahydrate, 3.6 g of zinc nitrate hexahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate as a hydrate, 3.0 g of sodium molybdate dihydrate and 20.0 g of sodium hydroxide in 600 ml of water is added to the obtained solution with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. The suspension is then stirred at this pH for one hour and at room temperature. The pH is then raised to 6.0 over one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension at 6.0 by further adding 1N sodium hydroxide solution (for example, using an appropriate pH maintaining device). The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry is then stirred for one hour at reflux, raising the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69g of a bright yellow pigment is obtained, which has the following elemental analysis results:

1.2% Zn, 18.3% V, 1.6% Mo. The pigment is in powder form.

The results of elemental analysis show the following molar ratios:

zinc to bismuth = 0.06 molybdenum to vanadium = 0.05.

Example 7 (Bi, Sr) (V, Mo) O ₄ Use of strontium nitrate in place of calcium nitrate

Dissolve 97.0 g of bismuth nitrate pentahydrate, 5.1 g of strontium nitrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 12.1 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to pH 3.5 with 30% sodium hydroxide solution. The suspension is then stirred for one hour at this pH at room temperature. The pH is then raised to 6.5 within 1 hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension at 6.5 by further adding 1N sodium hydroxide solution, for example by means of an appropriate pH-maintaining device. The pH is kept constant at 6.5 until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry was stirred for one hour at reflux, raising the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 71 g of a bright yellow pigment is obtained in the form of a powder having the following elemental analysis results:

1.9% Sr, 18.0% V, 5.5% Mo.

The results of elementary analysis point to the following molar ratios:

strontium to bismuth = 0.08 molybdenum to vanadium = 0.16.

Example 8 (Bi, Ca, Sr) (V, Mo) O ₄ Use of calcium nitrate and strontium nitrate

Dissolve 97.0 g of bismuth nitrate pentahydrate, 5.9 g of calcium nitrate tetrahydrate, 5.3 g of strontium nitrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 12.1 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added to the suspension obtained with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. Then, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.5 over one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension at 6.5 by further adding 1N sodium hydroxide solution (for example, using an appropriate pH maintaining device). The pH is kept constant 6.5 until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry was then stirred for one hour at reflux, whereupon the pH rose to about 8.5. The pH is adjusted to 9.8 in order to achieve an incomplete passage of the data bath into the solution. The suspension is then filtered, the filter cake is washed to remove salts and dried in an oven at 90 ° C. 71 g of a bright yellow pigment is obtained in the form of a powder having the following elemental analysis results:

2.3% Sr, 2.6% Ca, 17.2% V, 5.0% Mo.

The results of elementary analysis point to the following molar ratios:

strontium to bismuth = 0.09 calcium to bismuth = 0.23 molybdenum to vanadium = 0.15.

Example 9

Pure bismuth vanadate

Dissolve 97.0 g of bismuth nitrate pentahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 12.1 g of sodium molybdate dihydrate, 7.1 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. Then, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.0 within one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux, maintaining the pH of the suspension 6.0 by further adding 1 N sodium hydroxide solution (for example using an appropriate pH maintaining device). The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry was then stirred for one hour at reflux, resulting in a pH of approximately 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. A slightly reddish powder having a lower coloring than the corresponding bismuth adadate pigments of formula (I) is obtained.

Example 10 (Bi, Ca) (V, Mo) O ₄

Change the amount of fluoride

Dissolve 97.0 g of bismuth nitrate pentahydrate, 2.9 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate, 22.7 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is about 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. Then, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.0 within one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux while maintaining the pH at 6.0 by further adding 1N sodium hydroxide solution (for example using an appropriate pH maintaining device). The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry is then stirred for one hour at reflux, raising the pH to about 8.5. To achieve an incomplete transition

In the case of vanadate solution, adjust the pH to 9.8. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69 g of a bright yellow pigment are obtained in the form of a powder having the following elemental analysis results: 2.0% Ca, 18.6% V, 1.3% Mo.

The results of elementary analysis point to the following molar ratios:

bismuth calcium = 0.17 molybdenum to vanadium = 0.04.

Example 11 (Bi, Ca) (V, Mo) O ₄ Changing the amount of fluoride

Dissolve 97.0 g of bismuth nitrate pentahydrate, 2.9 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate, 0.8 g of sodium fluoride and 20.0 g of sodium hydroxide in 600 ml of water is added to the obtained solution with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. Then, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.0 within one hour by slowly adding 1N sodium hydroxide solution. Finally, the suspension is heated to reflux while maintaining the pH at 6.0 by further adding 1N sodium hydroxide solution (for example using an appropriate pH maintaining device). The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry is then stirred for one hour at reflux, raising the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69 g of a bright yellow pigment are obtained in the form of a powder having the following elemental analysis results: 2.0% Ca, 18.6% V, 1.3% Mo.

The results of elementary analysis point to the following molar ratios:

bismuth calcium = 0.17 molybdenum to vanadium = 0.04

Example 12 (Bi, Ca) (V, Mo) 0 ₄ Addition of fluoride ions after precipitation

97.0 g of bismuth nitrate pentahydrate, 2.9 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid are dissolved in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9. A solution of 7.1 g of sodium fluoride in 100 ml of water is then added and the pH is adjusted to 3.5 with 30% sodium hydroxide solution. Next, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.0 within one hour by slowly adding 1N sodium hydroxide solution. The suspension is then heated to reflux, maintaining the pH of the suspension at 6.0 by further addition of 1N sodium hydroxide solution (for example, using an appropriate pH maintaining device).

The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry is then stirred for one hour at reflux, raising the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. Subsequently, the suspension is filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69 g of a bright yellow pigment are obtained in the form of a powder having the following elemental analysis results: 2.0% Ca, 18.6% V, 1.3% Mo.

Elemental analysis results show the following molar ratios: calcium to bismuth = 0.17 molybdenum to vanadium = 0.04

Example 13 (Bi.Ca) (V, Mo) O ₄ Addition of fluoride ions at pH 6.0

97.0 g of bismuth nitrate pentahydrate, 2.9 g of calcium nitrate tetrahydrate and 72.0 g of 54% nitric acid are dissolved in 600 ml of water. A solution of 28.0 g of sodium vanadate hydrate, 3.0 g of sodium molybdate dihydrate and 20.0 g of sodium hydroxide in 600 ml of water is added with stirring. The pH of the suspension thus obtained is approximately 0.9 and is adjusted to 3.5 with 30% sodium hydroxide solution. Finally, the suspension is stirred for one hour at this pH at room temperature. Subsequently, the pH is raised to 6.0 within one hour by slowly adding 1N sodium hydroxide solution. The suspension is then heated to reflux and a solution of 7.1 g of sodium fluoride in 100 ml of water is added to the pigment suspension while the pH of the suspension is maintained at 6.0 by further addition of 1N sodium hydroxide solution (e.g. maintaining pH). The pH is kept constant until the suspension begins to turn yellow and the pH rises spontaneously. The pigment slurry is then stirred for one hour at reflux, raising the pH to about 8.5. The pH is adjusted to 9.8 to ensure incomplete passage of vanadate into solution. The suspension is then filtered and the filter cake is washed to remove salts and dried in an oven at 90 ° C. 69 g of a bright yellow pigment are obtained in the form of a powder having the following elemental analysis results: 2.0% Ca, 18.6% V, 1.3% Mo.

The results of elemental analysis show the following molar ratios: calcium to bismuth = 0.17 molybdenum to vanadium = 0.04.

Example 14

Example of use on HDPE - high density polyethylene g pigment according to the invention of Example 1 and 1000 g HDPE ( ^R Vastolen) are placed in a 3 liter glass flask and dry blended for 2 hours. The mixture is then extruded twice at 200 ° C and then granulated. Finally, 1.5 mm thick plates are produced on the spraying machine, and the spraying machine is subjected to a temperature of between 220 and 300 ° C for 5 minutes for the hot stability test. The pigment exhibits excellent heat stability.

Example 15

Example of use on PVC

0.5 g of the pigment obtained according to Example 1 is mixed with 76 g of polyvinyl chloride, 33 g of dioctyl phthalate, 2 g of dibutyltin dilaurate and 2 g of titanium dioxide, and the resulting mixture is rolled for 15 minutes at 160 ° C into thin films. The yellowish green color thus obtained has good coloring, good covering and migration stability and is also always in the light.

Example 16

Use in alkyl melamine baking enamels

Mix 60 g of a 60% solution of non-dried alkyd resin in xylene (trade name ^R Becksol 27-320), 36 g of a 50% solution of melamine-formaldehyde resin in a mixture of butanol and xylene (trade name ^R SuperBeckamin 13-501), 2 g xylene and 2g methylcellosol. 100 g of this mixture is mixed with a stirrer to a homogeneous lacquer solution.

g of the clear lacquer thus obtained, 10 of the pigment prepared according to Example 1.9 l of methyl isobutyl ketone and 135 g of glass beads (4.5 m diameter) are dispersed in a Vibratom pendulum mill for 16 hours. The lacquer thus obtained is stretched onto an aluminum strip coated with a vinyl lacquer using an Erichsen Type 238/1 fdm making machine. The lacquer obtained is left in the air for one hour and then baked for 30 minutes at 130 ° C. A bright yellow lacquered coating with a greenish shade is obtained which has good light fastness.

Work procedure for production of white filler varnish for determination of dyeing

In order to determine the color, the coloring of the lacquer is achieved as follows:

To adjust the standard dye saturation 1/25, determined according to DIN 53235, an amount of x g of the color pigment (bismuth nitrate pigment according to the invention) based on 10.0 g of titanium dioxide is added so that a total of x + y of 33.0 g is achieved.

Into a 180 ml glass vial with lid, gradually add:

100 g glass beads with a diameter of 3 mm, 28.0 g dispersing medium, x g color pigment and y g titanium dioxide (type RCR-2).

The dispersion environment consists of

34.4% alkyd varnish (Nebores ^R SP-24-70), alkyd resin phthalate, the phthalate being formed with soybean oil, 70% by weight, dissolved in white spirit (Shellsol ^R ),

47% solvent (Shellsol ^R H),

0,3% soya lecithin dispersant (Borchigen ^R ),

0.8% anti-skin-forming agent (Exkin 2, 10% in Shellsol ^R H),

1.1% wetting agent (1% Baysilon® MA in Shellsol ^R H),

16.4% desiccant (mixed octanoates, 6.0%

Zr, 1.2% Co, 3.0% Ca).

For dispersion, the glass container containing the contents is shaken for 15 minutes on a Skandex dispersion apparatus. 70g Nebores ^R SP-24-70 is then added and dispersed again on the Skandex dispersion apparatus for 10 minutes. A paint film is applied to the paint cards (carton, WDX mold) using the Bird Applicator BA-30, which is then allowed to air dry for 12 hours (wet film thickness).

80 µm, dry film thickness 35 µm). The dyeing is then measured.

Color measurement

The dyeing is measured on the lacquer film described above. The dye determination is measured on lacquer films which are made only on a white background. The determination of dyeing according to DIN 53235 is carried out as described above.

Datasheet Specifications Datacolor 3890 Spectrophotometer

geometry d / 8 ° measuring hole 27 mm wavelength 400 to 700nm, every 20nm

calibration

The white standard is made of barium sulfate for color measurement. For this purpose, tablets are compressed and the measured values are considered absolute. In contrast, the black standard is a closed tube lined with velvet (reflection value = 0%).

Production process of paint with full shades

Into a 180 ml glass vial with a lid is gradually added ml glass beads of 3mm diameter, 30.0 g dispersing medium and 21.0 g color pigment.

The dispersion environment consists of

28.6% ^R Setal 84 XX 70 and 71.4% xylene.

For dispersion, the glass container containing the contents is shaken for 15 minutes on a Skandex dispersing apparatus. 62 g of binder are then added and shaking is repeated on the Skandex dispersion apparatus for 5 minutes.

The binder consists of these components

53,5% ^R Setal 84 XX 70,

25,6% ^R Setamine US 132 BB 70

3.1% wetting agent (1.0% ^R Baysilon Oel a

98% Depanol ^R , 6.1% n-butanol (purest), 8.6% solvent ( ^R Solvesso 100) and 3.1% isophenone (3,5,5-trimethyl-2-cyclohexen-1-one). Method of coloring the paint The paint with full shade repels on the sheet. Details: and the white filler varnish spray pressure 0.25 MPa film thickness / dry) 80μοπ evaporation 30 minutes at room temperature firing 30 minutes at 130 ° C

The sheets are sprayed again, so that an opaque film with a thickness of 160 gm (dry film thickness) is finally used.

Color measurement

Standard color values X, Y and Z can be measured with full shades. Measurement of 16 reflective values and the calculation of standard values X, Y and Z are made according to DIN 5033 for the standard light type D 65 and 10 ° of the observer with a shiny closure. Calculated values are based on 4% surface remission.

The technical data of the measuring apparatus as well as the calibration are the same as indicated where they are given in connection with the determination of coloring.

Claims (7)

PATENT CLAIMS A process for the preparation of bismuth nitrate compounds of formula (I) (Bi, A) (V, D) O ₄ (I), wherein: A represents an alkaline earth metal, zinc or a mixture thereof and D represents molybdenum, tungsten or a mixture thereof and the molar ratio A: Bi is between 0.03 and 0.4 and the molar ratio D: V is between 0.01 and 0.3, as well as solid solutions based on them, (a) mixing with subsequent precipitation of a bismuth salt solution containing an alkaline earth metal salt or zinc salt or a mixture thereof, with an aqueous solution of a vanadium salt optionally containing a molybdenum salt or a tungsten salt, or a mixture thereof in said molar ratios; b) subsequent crystallization and standing of the particles which precipitated from the obtained suspension first in amorphous form, characterized in that from mixing to and / or the subsequent crystallization step from 0.1 to 3 moles of fluoride ions per 1 mol of bismuth are used. Method according to claim 1, characterized in that in formula (I), A is calcium or strontium and D is molybdenum or tungsten. A process according to claim 2, characterized in that in formula (I), A is calcium and D is molybdenum. 4. The process of claim 1, wherein fluoride ions are present in the vanadium salt solution. The process according to claim 1, characterized in that the fluoride ions are only mixed after the post-treatment. A process according to claim 5, characterized in that 1 mol of fluoride salt per 1 mol of bismuth is used. The process according to claim 1, characterized in that the obtained compounds are coated with an inorganic or organic protective layer.