WO1992019539A1

WO1992019539A1 - Bismuth-containing colorants

Info

Publication number: WO1992019539A1
Application number: PCT/US1992/003332
Authority: WO
Inventors: Robert P. Byrne; Robert P. Blonski; John J. Welch
Original assignee: Ferro Corporation
Priority date: 1991-04-24
Filing date: 1992-04-22
Publication date: 1992-11-12
Also published as: MX9201876A; AU1903692A

Abstract

This invention relates to colorants represented by the formula Bi2Ax-1DxOy wherein: A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; with the proviso that when A is Bi, D is other than a mixture consisting of V and Mo. These colorants are useful in providing colored compositions including: organic compositions such as plastics, rubbers, and the like; inorganic compositions such as ceramics, porcelain enamels, and the like; and coating compositions such as paints, printing inks, and the like; etc. The invention also provides for processes for making such colorants and for making such colored compositions. The invention also provides for such colorants in the form of particulate solids (e.g., pigments) having one or more protective coatings applied to the surface of such solids.

Description

& Title: BISMUTH-CONTAINING COLORANTS

Technical Field

This invention relates to bismuth-containing colorants and their use in

5 colored compositions (e.g., organic compositions such as plastics, rubbers, and the like; inorganic compositions such as ceramics, porcelain enamels, and the like; coating compositions such as paint, printing ink, and the like; etc.), and to processes for making such colorants and such colored compositions. This invention also relates to bismuth-containing colorants in the form of particulate solids (e.g., pigments)

10 which have one or more protective coatings applied to the surface of such solids.

Background of the Invention Cadmium sulfide and lead chromate are among the most commonly used yellow pigments. Unfortunately, these pigments are toxic and thus there is a need for alternative yellow pigments. i the search for such alternative yellow 15 pigments, interest has focused on the use of the bismuth-vanadate pigments. U.S.

Patent 4,026,722 discloses the use of bismuth-vanadate pigments represented by the formula

BiV0₄ xAl₂0₃ ySiO₂ wherein x is about 0.25-2.0, y is about 0.1-3.5, and the sum of x and y is equal to 20 or greater than 1. U.S. Patent 4,063,956 discloses the use of monoclinic bismuth vanadate pigment containing a precoat of one or more porous hydrous oxides (e.g., aluminum, silicon, titanium, etc.) and a dense overcoat of amorphous silica.

U.S. Patents 4,115,141 and 4,115,142 describe the use of monoclinic bismuth vanadate as a yellow pigment for coloring plastics and paints. These pig-

, 25 ments are prepared by reacting bismuth nitrate with an alkali vanadate to obtain a bismuth-vanadate gel and then subjecting the gel to aqueous digestion or calcination to produce the bismuth-vanadate pigment. U.S. Patent 4,230,500 discloses greenish-yellow, yellow and orange-yellow pigments which consist substantially of bismuth vanadate of monoclinic structure, bismuth phosphate of monoclinic structure and aluminum phosphate of orthorhombic structure and which, in the case of yellow and orange-yellow pigments also comprise a compound derived from Bi₂O₃ and V₂O₅.

U.S. Patent 4,251,283 discloses greenish-yellow pigments based on BiV0₄ made by the calcination, in the presence of air, of a mixture of BiP0₄, V₂0₅ and an oxide of Ca, Ba, Mg or Zn.

U.S. Patent 4,272,296 discloses bismuth-vanadate based yellow pigments diluted with 10-90% by weight of orthorhombic BaS0₄.

U.S. Patent 4,316,746 discloses molybdenum- or tungsten-containing, bismuth-vanadate yellow pigments represented by the formula

Bi - oMcVi- ⁰-* wherein M is Mo or W, x varies from 0.075 to 0.317 when M is Mo and from 0.059-0.265 when M is W. The reference indicates that these pigments may also contain a crystalline phase consisting of orthorhombic BaSO₄.

U.S. Patent 4,455,174 discloses a bismuth-vanadate yellow pigment represented by the formula

BiVO₄xBi₂MoO₆yBi₂WO₆ wherein x is 0.6-2.25 and y is 0-0.1. These pigments are prepared by a process in which a solution containing a bismuth (HI) salt, i vanadate and a molybdate is acidified until the Ph is less than zero. The pH of the acidic solution is then brought to 0.1-3.5 at 20-95 ^* C by means of an alkaline solution which may or may not contain a dissolved tungsten (VI) compound. The precipitated product and the reaction solution are left at 50-100" C for 30-120 minutes, and then separated from one another. The product is washed, dried, if required, and heated at 300-800 ^*C. Example 2 discloses the preparation of a pigment represented by the formula BiVO₄O.2Bi₂MoO_fi which corresponds to B^VsMoO^. German Offenlegungsschrift 3135281, which is the priority document upon which U.S. Patent 4,455,174 is based, indicates that in the above formula, both x and y have values in the range of 0-3 and the sum of x and y is in the range of 0.1-3.

U.S. Patent 4,752,460 discloses bismuth/vanadate/molybdate and bismuth/vanadate/tungstenate pigments represented by the formula (Bi,A)(V,D)O₄ wherein: A is an alkaline earth metal or zinc or mixture thereof; D is Mo, W or mixture thereof; the molar ratio of A:Bi is in the range of 0.1-0.4; and the molar ratio of D: V is in the range of 0-0.4. The notation (Bi, A) means that the bismuth is present in the form of the bismuth (HI) ion and is partly replaced by the divalent metal cation A. Vanadium is present as the vanadium (V) ion in the form of the vanadate ion and can be partly replaced by the hexavalent metal cation D as molybdate or tungstenate or mixtures thereof. The reference indicates that these pigments are in the form of tetragonal, scheelitelike crystal structures, and can be coated with an inorganic protective coating such as a silicon compound and a texture-improving agent such as wax.

R.A. Armstrong et al, "Bismuth Titanate Solid Solutions", Mat. Res. Bull. Vol. 7, pp. 1025-1034 (1972) indicates that ferro-electric Bi-T-Aa can be described as a sequence of alternating

(BiA)²⁺ and (Bi₂Ti₃O₁₀)²- layers stacked along a common axis. The Bi₂Ti₃O₁₂ units possess perovskitelike structures with corner-linked TiO₆ octahedra surrounding twelve coordinated bismuth ions. Bismuth oxide layers similar in structure to lead oxide separate the perovskite layers. The reference indicates that several di- and bivalent ions substitute readily for bismuth in the perovskite layer, but the octahedral site and the bismuth oxide layer are far less flexible, tolerating only very limited solid solution.

G.N. Subbanna et al, "Super Structures Exhibited by Oxides of the Aurivillius Family, (Bi₂θ₂)²⁺ (A^BA_a-n)^2"", Mat. Res. Bull., Vol. 22, pp. 205-209 (1987), discloses that BisTi₃Fe0₁₅ and Bi₇Ti₃Fe₃θ₂ι, which are n=4 and n=6 members of the family of oxides of the general formula (Bi )²* CAAC ^" consist of (A^B_aO^-_M)²* perovskite layers located between two (Bi₂0_)²⁺ layers. The reference indicates that these oxides show unusual super structures, possibly due to cation ordering.

Summary of the Invention This invention relates to colorants represented by the formula

wherein: A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; with the proviso that when A is Bi, D is other than a mixture consisting of V and Mo. These colorants are useful in providing colored compositions including: organic compositions such as plastics, rubbers, and the like; inorganic compositions such as ceramics, porcelain enamels, and the like; and coating compositions such as paints, printing inks, and the like; etc. The invention also provides for processes for making such colorants, and to a process for making such colored compositions. The invention also provides for such colorants in the form of particulate solids (e.g., pigments) having one or more protective coatings applied to the surface of such solids. In one aspect, this invention relates to a process for making a bismuth- vanadium-molybdenum-containing composition comprising: (A) preparing three separate aqueous compositions comprising a first aqueous composition having a pH in the range of about 0.5 to about 4; a second aqueous composition comprising bismuth and having a pH in the range of about 0.2 to about 3; and a third aqueous composition comprising at least one salt of vanadium and at least one salt of molybdenum and having a pH in the range of about 9 to about 14; (B) adding said second aqueous composition and said third aqueous composition simultaneously to said first aqueous composition to form a fourth aqueous composition, and maintaining said fourth aqueous composition at a temperature in the range of about 30°C to about 90°C for up to about 4 hours, said fourth aqueous composition comprising precipitated solids; (C) separating said solids from said fourth aqueous composition; and (D) heating said solids at a temperature in the range of about 250°C to about 675 °C for about 0.5 to about 30 hours to provide said bismuth-vanadium- molybdenum-containing composition. This invention also relates to bismuth- vanadium-molybdenum-containing compositions made by the foregoing process, and to colored compositions containing such bismum-vanadium-molybdenum-containing compositions.

Brief Description of the Drawings Fig. 1 is a ternary diagram expressed in molar quantities disclosing compositions of colorants that are provided for in accordance with one embodiment of the invention.

Fig. 2 is a ternary diagram expressed in molar quantities disclosing compositions of colorants that are provided for in accordance with another embodiment of the invention. Fig. 3 is a ternary diagram expressed in molar quantities disclosing compositions of colorants that are provided for in accordance with another embodiment of the invention.

Fig. 4 is a ternary diagram in molar quantities disclosing compositions of colorants that are provided for in accordance with another embodiment of the invention.

Fig. 5 is a ternary diagram expressed in molar quantities describing bismuth-vanadium-molybdenum-containing compositions made by the process disclosed herein.

Description of the Preferred Embodiments The colorants that are provided for in accordance with the present invention are represented by the formula

Bi₂A-.,D_xO_y (I) wherein: A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; with the proviso that when A consists solely of Bi, D is other than a mixture consisting solely of V and Mo. Li one embodiment of the invention, these colorants are pigments that are red-toned, orange, yellow, green or a combination thereof.

In Formula (T), x is preferably a number in the range of 1 to about 10, more preferably about 2 to about 6, more preferably about 3 to about 6.

In one embodiment of the invention, A is Bi, Y, La or a mixture of two or more thereof. In another embodiment, A comprises Bi. In another embodiment, A is Ba, Sr, Ca, Y, La or a mixture of two or more thereof. In still another embodiment of the invention, A is a mixture of Bi with one or more of Ba, Sr, Ca, Y or La.

In one embodiment of the invention, D is Ti, Sn, Ce, Mo, W or a mixture of two or more thereof. In another embodiment, D is V, Cr, Nb, Sb, Ta, Fe or a mixture of two or more thereof. In still another embodiment, D is V, Mo,

Ti, Sn or a mixture of two or more thereof.

In one embodiment of the invention, D is a mixture consisting of V and Mo. In this embodiment, the molar ratio of V to Mo is preferably in the range of about 11:1 to about 2: 1, more preferably about 5:1. In one embodiment of the invention, the colorants provided for herein are crystalline structures represented by the formula

(B^ AO-,,,)²- (π) wherein: said crystalline structure comprises one or more layers of (A_Λ.₁O_a0_3a+_)¹' stacked between layers of (Bi-A)²*; and n is the number of layers of (A_n-i-D_aO-j_n+i)^2* stacked between layers of (Bi₂O₂)²⁺ and is at least 1; with the proviso that when A is Bi, D is other than a mixture consisting of V and Mo. In Formula (H), A and D have the same meanings as in Formula (I), n is preferably a number in the range of 1 to about 10, more preferably 2 to about 6, more preferably 3 to about 6. In the embodiments wherein A is not present or A consists solely of Bi, D is other than a mixture consisting solely of V and Mo. When D is a mixture consisting solely of a mixture of V and Mo, A must be present and is either (1) Bi in combination with one or more of Ba, Sr, Ca, Y or La, or (2) one or more of Ba, Sr, Ca, Y or La. The intention herein is that the colorants represented by Formulae

(I) or (H) are other than pigments made up solely of Bi, V, Mo and O.

In one embodiment of the invention, the compounds of Formulae (T) or (H) have compositions within the quadrilateral defined by the points I, π, HI and IV of Fig. 1. In Fig. 1, AO_z refers to La₂O₃, Y₂O₃, 2CaO, 2BaO, 2SrO, or a mixture thereof. Up to about 35% on a molar basis, more preferably up to about

25 % , more preferably up to about 15 % of the Bi₂0₃ can be replaced by A0₂. In Fig. 1, D'₂O_z refers to V₂0₅, Cr₂O₃, Nb₂O₅, Sb₂O₃, Ta₂O₅ or FeA. The comers of the quadrilateral I-π-DI-IVof Fig. 1 have the following compositions, in terms of molar percentage:

In one embodiment of the invention, the compounds of Formulae (I) or (H) have compositions within the quadrilateral defined by the co ers I, π, HI and IV of Fig. 2. In Fig. 2, AO_r refers to La₂0₃, Y₂0₃, 2CaO, 2BaO, 2SrO, or a mixture thereof. Up to about 35% on a molar basis, more preferably up to about 25 % , more preferably up to about 15 % of the Bi₂0₃ can be replaced by AO_z. In Fig. 2, D"O_z refers to TiO₂, SnO₂, CeO₂, MoO₃ or WO₃. The comers of the quadrilateral

I-H-HI-IV of Fig. 2 have the following compositions, in terms of molar percentage:

In one embodiment of the invention, the compounds of Formulae (I) or (H) have compositions within the quadrilateral defined by the points I, II, HI and IV of Fig. 3. In Fig. 3, AO_z refers to La₂0₃. Y , 2CaO, 2BaO, 2SrO, or a mixture thereof. Up to about 35% on a molar basis, more preferably up to about 25 % , more preferably up to about 15 % of the Bi₂O₃ can t ^e replaced by AO_z. Li Fig.

3, D'A refers to V₂O₅. Cr₂O_3> b₂O₅. SbA, Ta₂0₅ or FeA. D"O_z refers to T , SnO-_∑, CeOj, Mo0₃ or WO₃. The comers of the quadrilateral I- π-HI-IV of Fig. 3 have the following compositions, in terms of molar percentage:

In one embodiment of the invention, the compounds of Formulae ~) or (H) have compositions within the quadrilateral defined by the points I, π, m and

IV of Fig. 4. In Fig. 4, AO_z refers to La₂O₃, Y₂O_3» 2CaO, 2BaO, 2SrO, or a mixture thereof. Up to about 35% on a molar basis, more preferably up to about

25% , more preferably up to about 15% of the Bi₂O₃ can be replaced by AO_z. In Fig.

4, D'A refers to V₂O₅. Cr₂O₃, NbA, SbA, Ta₂O₅ or FeA. D"O_z refers to TiO₂, SnO₂, CeO₂, MoO₃ or WO₃. Li Fig. 4, the designations 11:1, 5:1 and 2:1 refer to molar the ratio of V₂0₅ to 1 2 D'A ^or D"O_z. These molar ratios are provided for at all points on the vertical lines marked by such designations that extend from the uppermost comer or apex of Fig. 4 downwardly. The line referring to a molar ratio of 2:1 passes through points II, VII and HI the molar ratio of V₂O₅ to 1/2 D'A ^or D"O_z is 2:1. Similarly, the line referring to a molar ratio of 5:1 passes through points V and VHI and thus the molar ratio of V₂O₅ to 1/2 D'A or D"O_z at such points is 5:1. The line referring to a molar ratio of 11:1 passes through points I and IV and thus the molar ratio of V₂0₅ to 1/2 D'A or D"O_z at such points is 11: 1. The comers of the quadrilateral I-H-HI-IV of Fig. 4 have the following compositions, in terms of molar percentage:

In one embodiment of the invention, the compounds of Formulae (I) or (II) have compositions within the quadrilateral defined by the points V, VI, VII and VHI of Fig.4. The comers of the quadrilateral V-VI-Vπ-Vfflhave the following compositions, in terms of molar percentages:

In one embodiment of the invention, the compounds of Formulae (I) or (H) are made by a co-precipitation process Q) comprising the steps of:

(A) preparing a first aqueous composition having a pH preferably in the range of about 0.5 to about 5, more preferably about 1 to about 4;

(B) preparing a second aqueous composition comprising at least one salt of bismuth or bismuth metal, and optionally at least one salt of component A or the metal A, and having a pH preferably in the range of about 0.2 to about 5, more preferably about 0.5 to about 4; (C) preparing a third aqueous composition comprising at least one salt of component D or the metal D; with the proviso that if component A is not present or if component A consists solely of Bi, component D is other than a mixture consisting solely of V and Mo; said third aqueous composition preferably having a pH that is less acidic (i.e., more alkaline) than said second aqueous composition;

(D) adding said second aqueous composition and said third aqueous composition simultaneously to said first aqueous composition to form a fourth aqueous composition comprising precipitated solids, said precipitated solids comprising Bi, component D and optionally component A; (E) maintaining said fourth aqueous composition from step (D) at a temperature preferably in the range of about 25 ^* C to about 90 ^* C, more preferably about 30 "C to about 70 ^*C for up to about 3 hours, preferably up to about 2 hours; (F) deliquifying said fourth aqueous composition from step (E) to provide deliquified solids; and (G) heating said deliquified solids from step (F) at a sufficient temperature and for an effective period of time to provide said bismuth-containing composition. The pH of the fourth aqueous composition is from about 0.5 to about 6, more preferably about 1 to about 5.

The first aqueous composition preferably has a temperature in the range of about 25^*C to about 90 C, more preferably about 30^*C to about 70^*C. .Any inorganic acid can be used to provide the required pH for the first aqueous composition. These include nitric acid, hydrochloric acid and sulfuric acid.

The bismuth salt and the salt of component A that are used to form the second aqueous composition are preferably nitrates, oxalates, carbonates, oxides, hydroxides, sulfates or halides (e.g., chlorides). Examples of such bismuth salts include Bi₂(NO₃)₃.5H₂O, Bi(OH)₃, BiCl₃, Bi₂O₂ SCyH₂O and Bi₂0₂C0₃. Examples of salts of component (A) that are useful include BaMo0₄, Ba(OH)₂Η₂0, Ba⁽_! -H BaO, CaCO₃, Ca(OH)₂, CaMoQ,, CaSO₄2H₂O, Ca(N0₃)₂-4H₂O, CaO, ^QiC -HA Y2O3, Y₂(C0₃)₃-3H₂0, Y(NO₃)₃-4H₂0, YC1₃H₂0, Y(OH)₃, Y(SO₄)₃8H₂O, La₂(CO₃)₃8H₂O, LaCl₃, La(OH)₃, La₂(CA)₃-9H₂O, La₂0₃, SrC0₃, SrCjCyHA SrSO₄, Sr(OH)₂ and SrMoO₄. The concentration of bismuth in the second aqueous composition is preferably in the range of about 0.25 to about 4 gram- moles per liter, more preferably about 0.35 to about 2.5 gram-moles per liter. The concentration of component A in the second aqueous composition is preferably up to about 1.5 gram-moles per liter, more preferably in the range of about 0.2 to about

0.8 gram-moles per liter. Any inorganic acid can be used to provide the desired pH for the second aqueous composition, with nitric acid, sulfuric acid and hydrochloric acid being preferred. The temperature of the second aqueous composition is preferably in the range of about 25"C to about 70^*C, more preferably about 30"C to about 55 'C.

The salts of component D that are used in the third aqueous composition are preferably alkali metal (e.g., Na, K) or ammonium salts, nitrates, oxalates, carbonates, oxides, hydroxides, sulfates or halides (e.g., chlorides). Examples include NH-ΛA, Na₃V0₄, NaV0₃, Na₂Mo0₄-2H₂0, TiO*,, 5TiO₂N₂O₅-6H₂0, K₂TiO(CA)₂-2H₂0, Ti₂(S0₄V8H₂O, TiO,, TiOSO₄, SnCV5H₂O,

SnCl₂2H₂O, SnCA, SnSO₄, SnO₂, and SnO₂xH₂O. Any base can be used to provide the desired pH. Examples of useful bases include NaOH, NH OH and KOH. The concentration of component D in the third aqueous composition is preferably from about 0.1 to about 4 gram-moles per liter, more preferably about 0.5 to about 2 gram-moles per liter. The temperature of the third aqueous composition during step

(C) is preferably in the range of about 25 ^*C to about 90 ^*C, more preferably, about 30°C to about 50°C.

During step (D) the second and third aqueous compositions are added to the first aqueous composition simultaneously to effect the formation of the fourth aqueous composition comprising an aqueous solution containing precipitated solids.

The precipitated solids comprise Bi, component D and optionally component A. The simultaneous addition of the second and third aqueous compositions to the first aqueous composition is critical to achieving the precipitation of solids that have superior colorant characteristics. The addition is preferably conducted at steady flow rates of each of said second and third aqueous compositions. The addition can be effected over a period of about one-half to about 4 hours, more preferably about one- half to about 2 hours. The first aqueous composition is preferably subjected to agitation during such addition. The How rate of the second aqueous composition can be in the range of about 2 to about 10 cc/minute, more preferably about 4 to about 8 cc/minute. The flow rate of the third aqueous composition can be in the range of about 1 to about 8cc/minute, more preferably about 2 to about 7 cc/minute. The temperature of the fourth aqueous composition is preferably in the range of about 25'C to about 90^*C, or about 25°C to about 70°C, more preferably about 30 C to about 70^*C. The pH of the fourth aqueous composition is preferably in the range of about 0.5 to about 6, more preferably about 1 to about 5.

The concentrations of Bi, component D and component A in the second and third aqueous compositions, and the amount of such second and third aqueous compositions that are added to the first aqueous composition are interdependent and selected so as to provide for ratios of Bi to component D to component A in the final product in accordance with ratios indicated in Formulae (I) or (H). Thus, for example, if the concentration of Bi in the second aqueous composition is relatively high, the amount of such second aqueous composition that is added to the first aqueous composition during step (D) is relatively low. Similarly, if the amount of Bi that is added during step (D) is relatively low, the amounts of component D and component A that are added during step (D) are also relatively low in order to provide the desired ratios of Bi to component D to component A.

An effective amount of a base can be added to the fourth aqueous composition subsequent to step (D) but prior to step (E) to increase the concentration of bismuth in the precipitate. Examples of such bases include sodium, potassium or ammonium hydroxide. Typically, sufficient base is added to raise the pH of the fourth aqueous composition to a level in the range of about 1 to about 6, more preferably about 1 to about 4. Preferably, the base is added over a period of about 1 to about 3 hours, more preferably about 1 to about 2 hours.

After the additions during step (D) are completed and any additional base is added, the- fourth aqueous composition is maintained at a temperature preferably in the range of about 25 ^*C to about 90^* C, more preferably about 25 "C to about 70 "C for preferably up to about 3 hours, more preferably up to about 2 hours. The precipitated solids are then separated from the fourth aqueous composition using conventional techniques (e.g., filtration), and preferably washed and dried. The solids are then heated at a sufficient temperature for an effective period of time to provide a bismuth-containing solids composition corresponding to Formulae ) or (H). In one embodiment of the invention, this heating step is conducted at a sufficient temperature and for an effective period of time to provide a single-phase crystalline structure. The heating (or calcination) step (G) can be conducted using a single step or a multi-step heating cycle.

In one embodiment of the invention the temperature of the solids is increased to a peak temperature in the range of preferably about 525 ^*C to about 950 ^*C over a period of preferably about 1 minute to about 10 hours, maintained at said peak temperature for preferably about 1 to about 20 hours, and cooled to ambient temperature. In another embodiment, the temperature of the solids is increased to a peak temperature in the range of preferably about 525 "C to about 675 ^*C, more preferably about 575 ^*C to about 625 ^*C, more preferably about 600^* C, over a period of preferably about 1 to about 20 minutes, maintained at said peak temperature for preferably about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours, and cooled to ambient temperature.

In one embodiment, the process includes the additional step of heating said bismuth-containing composition from step (G) at a temperature in the range from about 525°C to about 950°C for about 1 to about 10 hours, preferably about 2 to about 6 hours. In another embodiment, the temperature of the solids is increased to an intermediate temperature in the range of preferably about 450^*C to about 550^*C, more preferably about 490"C to about 510^*C, more preferably about 500'C, over a period of preferably about 1 to about 4 hours, more preferably about 2 hours, maintained at said intermediate temperature for about 1 to about 4 hours, more preferably about 2 hours, increased to a peak temperature in the range of about 600 'C to about 700^* C, more preferably about 625 'C to about 675 "C, more preferably about 650 "C, ova: a period of about 1 to about 4 hours, more preferably about 2 hours, maintained at said peak temperature for about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours, and cooled to ambient temperature. In another embodiment, the temperature of the solids is increased to an intermediate temperature in the range of about 250 ^* C to about 450 " C over a period of about 1 to about 10 minutes, maintained at said intermediate tem¬ perature for preferably about 1 to about 10 hours, more preferably about 1 to about 4 hours, more preferably about 2 hours, increased to a peak temperature in the range of preferably about 525" C to about 675^* C over a period of about 1 to about 10 minutes, maintained at said peak temperature for about 1 to about 10 hours, more preferably about 1 to about 4 hours, more preferably about 2 hours, and cooled to ambient temperature. In another embodiment, the temperature of the solids is increased to an intermediate temperature in the range of about 550 ^* C to about 625 ^* C , more preferably about 575 ^* C to about 625 ^* C, more preferably about 600 ^* C, over a period of about 1 to about 4 hours, more preferably about 2 hours, maintained at said intermediate temperature for preferably about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours, increased to a peak temperature in the range of preferably about 650 ^*C to about 950 "C, more preferably about 700 "C to about 900 "C, over a period of about 1 to about 4 hours, more preferably about 2 hours, maintained at said peak temperature for about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours, and cooled to ambient temperature. In each of the foregoing embodiments the solids are preferably oven-cooled from the peak temperature to ambient temperature over a period of about 0.5 to about 16 hours, more preferably about 4 to about 12 hours.

In one embodiment of the invention, the compounds of Formulae (I) or (H) are made using a solid-state process (I) comprising the steps of:

(A') preparing a mixture comprising metallic Bi or at least one compound of Bi, metallic D or at least one compound of component D, and optionally metallic A or at least one compound of component A; (B') increasing the temperature of said mixture from step (A') to an intermediate temperature, preferably in the range of about 550 "C to about 625 "C, more preferably about 590 "C to about 610^* C, more preferably about 600^* C, over a period of preferably up to about 4 hours, more preferably about 1 to about 3 hours, more preferably about 2 hours;

(C) mamtaining the temperature of said mixture at said intermediate temperature for preferably about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours;

(D') increasing the temperature of said mixture from said intermediate temperature to a peak temperature in the range of preferably about

650'C to about 950^*C, more preferably about 700'C to about 900^*C, over a period of preferably up to about 4 hours, more preferably about 1 to about 3 hours, more preferably about 2 hours;

(E') maintaining the temperature of said mixture at said peak temperature for preferably about 1 to about 20 hours, more preferably about 2 to about 16 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours; and

(F') cooling said mixture from step (E') to ambient temperature, preferably over a period of about 8 to about 24 hours, more preferably about 10 to about 16 hours, to provide the bismuth-containing composition of Formulae (I) or

(H). i one embodiment of the invention, the peak temperature during step (D') is preferably in the range of about 675" C to about 725 ^*C. i another embodiment the peak temperature during step (D') is preferably in the range of about 725^* C to about 775 ^*C. In another embodiment, the peak temperature during step

(D') is preferably in the range of about 775^* C to about 825^* C. In another embodiment the peak temperature during step (D') is preferably in the range of about 825 ^* C to about 875 ^* C. In still another embodiment the peak temperature during step (D') is preferably in the range of about 875 ^*C to about 925 ^*C. fii one embodiment of the invention, the compounds of Formulae (I) or (H) are made using a solid-state process (H) comprising the steps of:

(A") preparing a mixture comprising metallic Bi or at least one compound of Bi, metallicD or at least one compound of component D, and optionally metallic A or at least one compound of component A;

(B") increasing the temperature of said mixture from step (A') to a peak temperature, preferably in the range of about 500^* C to about 700" C, more preferably about 550 ^*C to about 650 ^*C, more preferably about 575 ^*C to about

625 ^*C, more preferably about 600 ^*C, over a period of preferably up to about 4 hours, more preferably about 1 to about 3 hours, more preferably about 2 hours;

(C") maintaining the temperature of said mixture at said peak temperature for preferably about 1 to about 60 hours, more preferably about 1 to about 20 hours, more preferably about 1 to about 10 hours, more preferably about 1 to about 4 hours; and (D") cooling said mixture from step (C") to ambient temperature, preferably over a period of about 4 to about 48 hours, more preferably about 10 to about 24 hours to provide the bismuth-containing composition of Formulae (1) or (H). The bismuth compound that is used during steps (A') or (A") is preferably Bi₂O₃ °^{r a} precursor of Bi₂O₃. Examples of such precursors include bismuth metal, Bi₂M0₃0₁₂ and Bi A)*-,. The compounds of component D and component A that are useful are preferably oxides, carbonates, hydroxides, oxalates or nitrates. Examples of the compounds of component D include TiO*-., SnO₂, CeO₂, Mo0₃, W0₃, VA_> CrA, Ta₂O_s, FeA, SbA, SbA, NbA, or a mixture of two or more thereof. Precursors of the foregoing can be used, examples of which include NE^VO-,, Bi₂MoA₂, Bi(VO₃)₃, Bi^CrO^, Bi₂WO₆, CeVO₄, V₂MoO₈, BiCrO₃- lEαamples of the compounds of component A include Bi₂O₃, La A, Y₂O_3> CaO, BaO, SrO and mixtures of two or more thereof. Precursors of the foregoing compounds can also be used, examples of which include Bi₃YO₆, BaBi0₃ and CaBi₂0 . The ratios of Bi to component D to component A that are used in steps (A') or (A") are selected so as to provide for ratios Bi to D to A in the final product in accordance with the ratios indicated in Formulae ( ) or (H).

With each of the inventive processes, the solids are reduced to a desired particle size, preferably in the range of about 0.1 to about 2μm, more prefer- ably about 0.1 to about 1 μm, using techniques known in the art (e.g., grinding, crushing, etc.).

In the event the product solids from any of the inventive processes contain more than a single crystalline phase, which can be detected using x-ray diffraction, it is preferred that the solids be heated again to a temperature in the range of about 700^* C to about 900^* C for preferably about 1 to about 20 hours, more preferably about 1 to about 10 hours, to obtain a single-phase product. This reheating step can be repeated until a preferred, single-phase product is obtained.

The temperatures that these compositions are heated to are dependent upon the particular elements that are used for components A and D, it being desired that the melting point of the composition represented by Formulae ( or (H) not be exceeded during heating. When component D comprises Mo, it is preferred that the peak temperature not exceed about 700^* C. When D comprises Cr, it is preferred that the peak temperature not exceed about 750 ^*C. When D comprises Ti, Sn, W or Ce it is preferred that the peak temperature not exceed about 800 ' C. When D comprises Sb, Nb or Ta it is preferred that the peak temperature not exceed about 900 C.

In one embodiment, the bismuth-containing composition is a bismuth- vanadium-molybdenum-containing composition. The bismuth-vanadium- molybdenum- Ontaining compositions are parepared by a co-precipitation process (H) comprising the steps of: (A*) preparing three separate aqueous compositions comprising: a first aqueous composition having a pH preferably in the range of about 0.5 to about 4, more preferably about 0.5 to about 1.5; a second aqueous composition comprising bismuth and having a pH preferably in the range of about 0.2 to about 3, more preferably about 0.2 to about 2; and a third aqueous composition comprising at least one salt of vanadium and at least one salt of molybdenum, said third aqueous composition preferably having a pH in the range of about 9 to about 14, more preferably about 10 to about 14;

(B*) adding said second aqueous composition and said third aqueous composition simultaneously to said first aqueous composition to form a fourth aqueous composition, and maintaining said fourth aqueous composition at a temperature preferably in the range of about 30" C to about 90 ^*C, more preferably about 50^* C to about 80 ^*C, for preferably up to about 4 hours, more preferably up to about 2 hours, more preferably about 0.1 to about 2 hours, said fourth aqueous composition comprising precipitated solids; (C*) separating said solids from said fourth aqueous composition; and

(D*) heating said solids at a temperature in the range of about 250 ^* C to about 675 "C for about 0.5 to about 30 hours to provide said bismuth-vanadium- molybdenum-containing composition.

The first aqueous composition preferably has a temperature in the range of about 30^*C to about 90X, more preferably about 50^*C to about 80'C. Any inorganic acid can be used to provide the required pH for the first aqueous composition. In one embodiment, the acid is nitric acid. Examples of other acids include hydrochloric acid and sulfuric acid.

The bismuth that is used to form the second aqueous composition can be bismuth metal or it can be one of the above described salts. In one embodiment, examples of such bismuth salts include Bi(NO₃)₃-5H₂O, Bi(OH)₃, BiCl₃, B_ASO₄H₂O, and Bi₂O₂CO₃. The concentration of the bismuth in the second aqueous composition is preferably in the range of about 50 to about 800 grams per liter, more preferably about 50 to about 400 grams per liter. .Any inorganic acid can be used to provide the desired pH for the second aqueous composition, with nitric acid being preferred.

Examples of other acids include hydrochloric acid and sulfuric acid. The temperature of said second aqueous composition is preferably in the range of about 30" C to about 50'C, more preferably about 30^*C to about 40'C.

The salts of vanadium and molybdenum that are used in the third aqueous composition are preferably alkali metal (e.g., Na, K) or ammonium salts. Examples include NI-VVO*-,, Na₃VO₄, NaVO₃, Na₂MoO₄ ^*2H₂O,

and (NH₄)₂MoO₄. Any base, such as NaOH, can be used to provide the desired pH. Examples of other bases include potassium hydroxide and ammonium hydroxide. The concentration of the vanadium in the third aqueous composition is preferably about 5 to about 200 grams per liter, more preferably about 12 to about 80 grams per liter.

The concentration of the molybdenum in said third aqueous composition is preferably from about 1 to about 100 grams per liter, more preferably about 5 to about 60 grams per liter. In one embodiment of the invention the molar ratio of vanadium to molybdenum in said third aqueous composition is in the range of preferably about 11:1 to about 2:1, more preferably about 7:1 to about 3:1, more preferably about 5:1.

The temperature of the third aqueous composition is preferably in the range of about 30'C to about 70^*C, more preferably about 30^*C to about 50'C.

During step (B*) the second and third aqueous compositions are added to the first aqueous composition to provide for the formation of the fourth aqueous composition. The fourth aqueous composition is an aqueous solution that contains precipitated solids. This co-precipitation step is critical to this invention. The addition is preferably conducted at steady flow rates of each of said second and third aqueous compositions over a period of about 30 minutes to about 3 hours, more preferably about 1 to about 2 hours. The first aqueous composition is preferably subjected to agitation during such addition. The flow rate of the second aqueous composition can be in the range of about 2 to about 10 cc/minute, more preferably about 4 to about 8 cc/minute. The flow rate of the third aqueous composition can be in the range of about 1 to about 9 cc/minute, more preferably about 2 to about 7 cc/minute. The temperature of the fourth aqueous composition is preferably in the range of about 30 ^* C to about 90 ^* C, more preferably about 50 ^* C to about 80 ^* C. The pH of the fourth aqueous composition is preferably in the range of about 0.5 to about 6, more preferably about 0.5 to about 3, more preferably about 0.8 to about 1.5.

An effective amount of a base can be added to the fourth aqueous composition during step (B*) to increase the concentration of bismuth in the precipitate. Examples of such bases include sodium hydroxide, ammonium hydroxide and potassium hydroxide. Typically, sufficient base is added to raise the pH of the fourth aqueous composition to a level in the range of about 1 to about 6, more preferably about 1 to about 3. Preferably, the base is added over a period of about 0.5 to about 2 hours, more preferably about 0.5 to about 1 hour. After the additions during step (B*) are completed and any additional base is added, the fourth aqueous composition is maintained at a temperature preferably in the range of about 30^*C to about 90^*C, more preferably about 50^*C to about 80 ^*C for preferably up to about 4 hours, more preferably up to about 2 hours, more preferably about 0.1 to about 2 hours. The precipitated solids are then separated from the fourth aqueous composition using conventional techniques (e.g., filtration), and preferably washed and dried.

The solids are then heated or calcined at a temperature in the range of about 250^* C to about 675 ^*C for about 0.5 to about 30 hours, more preferably about

1 to about 20 hours, to provide the desired bismum-vanadiummolybdenum-cont-ttning solids composition. In one embodiment of the invention, this heating step is conducted at a sufficient temperature and for an effective period of time to provide a single-phase crystalline structure. The heating or calcination step (D*) can be conducted using a single step or a multi-step heating cycle. In one embodiment of the invention, the temperature of the solids is increased to a peak temperature of about 525^*C to about 675'C, more preferably about 575^*C to about 625'C, more preferably about 600 ^*C, over a period of preferably about 1 minute to about 4 hours; maintained at said peak temperature for preferably about 1 to about 10 hours, more preferably about 2 to about 6 hours, more preferably about 4 hours; and cooled to ambient temperature. In another embodiment, the temperature of the solids is increased to an intermediate temperature in the range of about 250 ^* C to about 450 ^* C over a period of preferably about 1 minute to about 4 hours, more preferably about

1 minute to about 2 hours; maintained at said intermediate temperature for preferably about 1 to about 10 hours, more preferably about 1 to about 4 hours, more preferably about 2 hours; increased to a peak temperature in the range of preferably about 525^* C to about 675^* C, more preferably about 575 ^*C to about 625 ^*C, more preferably about 600 ^*C, over a period of preferably about 1 minute to about 4 hours, more preferably about 30 minutes to about 3 hours; maintained at said peak temperature for about 1 to about 10 hours, more preferably about 1 to about 4 hours, more preferably about 2 hours; and cooled to ambient temperature. In each of the foregoing embodiments the solids are cooled from the peak temperature to ambient temperature over a period of preferably about 6 to about 16 hours, more preferably about 10 hours.

The solids are reduced to a desired particle size, preferably in the range of about 0.1 to about 2μm, more preferably about 0.2 to about 0.8μm, using techniques known in the art (e.g., crushing, grinding, etc.).

In one embodiment of the invention, it is preferred to make a single- phase product. In said embodiment, if the product solids contain more than a single crystalline phase, which can be detected using x-ray diffraction, it is preferred that the solids be heated again to a temperature in the range of about 525 ^*C to about 675 ^* C, more preferably about 575 ^* C to about 625 ^* C, for preferably about 1 to about

20 hours, more preferably about 1 to about 10 hours, to obtain a single-phase product. This reheating step can be repeated until a single-phase product is obtained. In one embodiment of the invention, the bismuth-vanadium-molyb¬ denum-containing compositions made by the inventive process are represented by the formula

Bi,V_bMoA (HI) wherein: a is a number that is preferably in the range of about 2 to about 11, more preferably about 4 to about 7; b is a number that is preferably in the range of about 0.7 to about 10, more preferably about 2 to about 6; c is a number that is preferably in the range of about 0.08 to about 4, more preferably about 0.5 to about 2; and d is the number of oxygens needed to fulfill the valence requirements of Bi, V and Mo. In one embodiment of the invention, the ratios of bismuth to vanadium to molybdenum that are used in step (A*) of the inventive process are selected to provide ratios of bismuth to vanadium to molybdenum in the final product corre- sponding to the ratios of bismuth to vanadium to molybdenum indicated in Formula

(πi).

In one embodiment of the invention, the bismuth-molybdenum-vana- dium-containing compositions made by the inventive process have compositions within the quadrilateral defined by the points I, H, HI and IV of Fig. 5. In Fig. 5, the designations Mo:2V, Mo:5V and Mo: 1 IV refer to molar the ratio of V to Mo. These molar ratios are provided for at all points on the vertical lines marked by such designations in Fig. 5. The line designated Mo:2V passes through points π, VI, VII and HI and thus at each of said points π, VI, VII and HI the molar ratio of V to Mo is 2:1. Similarly, the line designated Mo:5V passes through points V and VHI and thus the molar ratio of V to Mo at such points is 5:1. The line designated Mo:llV passes through points I and IV and thus the molar ratio of V to Mo at such points is

11:1. The corners of the quadrilateral I-π-iπ-IV of Fig. 5 have the following compositions, in terms of molar percentage: SiA

I 64.9

E 60 m 45.5

IV 50

In one embodiment of the invention, the ratios of bismuth to vanadium to molybdenum that are used in step (A*) of the inventive process are selected to provide ratios of bismuth to vanadium to molybdenum in the final product corre¬ sponding to the ratios of bismuth to vanadium to molybdenum within the quadrilateral

In one embodiment of the invention, the bismuth-molybdenum-vana¬ dium-containing compositions made by the inventive process have compositions within the quadrilateral defined by the points V, VI, VH and VHI of Fig. 5. The comers of the quadrilateral V-VI- Vn-VHI have the following compositions, in terms of molar percentages:

In one embodiment of the invention, the ratios of bismuth to vanadium to molybdenum that are used in step (A*) of the inventive process are selected to provide ratios of bismuth to vanadium to molybdenum in the final product corre¬ sponding to the ratios of bismuth to vanadium to molybdenum within the quadrilateral V-VI-Vπ-Vπi of Fig. 5.

To improve the properties (e.g., stability to heat, light and chemical attacks), of the colorants used herein, it is advantageous to coat the bismuth- containing compositions during their preparation or in an af ertreatment in accordance with known processes with an inorganic protective coating. For this purpose, inorganic substances such as aluminum, titanium, antimony, cerium, zirconium, silicon compounds, zinc phosphate or mixtures thereof are applied as a coating to the bismuth-containing compositions. This coating application can be carried out in one or more stages using known techniques. The amount of inorganic coating agent that is applied is preferably up to about 50% by weight, more preferably about 2% to about 50% by weight, more preferably about 5% to 50% by weight, based on the combined weight of the colorant and coating agent.

To improve certain pigment properties, the bismuth-containing compositions can be treated with one or more texture-improving agents. These include, for example, long-chain aliphatic alcohols, esters, acids or salts thereof, amines, amides, waxes or resinous substances, such as abietic acid, hydrogenation products, esters or salts thereof. .Also included are nonionic, anionic or cationic surface-active agents. These texture-improving agents are applied as a coating to the colorant using known techniques. The coating can be applied to the bismuth- containing compositions with or without first applying an inorganic coating of the type referred to above. If used in combination with such inorganic coating, the texture-improving agent is applied as a second coat or overcoat overlying the inor¬ ganic protective coating. The amount of texture-improving agent that is used is preferably up to about 70% by weight, more preferably about 0.1 % to about 70% by weight, based on the total weight of the resulting product.

In one embodiment of the invention, the bismuth-containing compositions are pigments that are initially coated with at least one coating of silica. Then at least one coating of at least one wax such as a polyolefin wax is applied over the silica coating to provide a pigment with enhanced abrasion resistance and color stability. The amount of silica that is applied is preferably up to about 50% by weight, more preferably 2% to about 50% by weight, more preferably about 5% to about 50% by weight, based on the combined weight of the pigment and the silica. The amount of wax that is applied is preferably up to about 70% by weight, more preferably about 0.1% to about 70% by weight, based on the total weight of the resulting product. In one embodiment, when the colorant is a bismuth-vanadium- molybdenum-containing composition, the amount of wax is more preferably about 10% to about 70% by weight, based on a total weight of the resulting product. The procedures and materials used for coating lead chromate pigments with silica and polyolefin wax disclosed in U.S. Patent 3,773,535 at Col. 2, line 22 to Col. 7, line 68 are applicable to coating the pigments used herein; the foregoing section of U.S.

Patent 3,773,535 is incorporated herein by reference for its disclosure of such coating procedures and materials.

The bismuth-containing compositions have good pigment properties and are suitable for coloring organic compositions such as plastics, rubbers, and the like; inorganic compositions such as ceramics, porcelain enamels, and the like; and coating compositions such as paint, printing ink, and the like. The color exhibited by the compound of Formula (J and (H) is dependent upon the particular components employed, but generally is yellow, orange, red-toned, green or a combination thereof. In one embodement, when using bismuth, vanadium, molybdenum-containing compositions, a color exhibited by these compounds is dependent upon the particular ratio of components that are employed, but generally is yellow.

The plastic or rubber compositions and coating compositions that can be colored according to the invention are based on polymeric materials that can be of natural or synthetic origin. Examples include natural resins or drying oils, rubber or casein. Also included are modified natural substances, such as chlororubber, oil-modified alkyd resins, viscose, cellulose ethers or esters, such as cellulose acetate, cellulose propionate, cellulose acetobutyrate or nitrocellulose. .Also included are wholly synthetic organic polymers (thermosets and thermoplastics) obtained by polymerization, polycondensation or polyaddition. Examples include polyolefins, such as polyethylene, polypropylene or polyisobutylene, substituted polyolefins, such as polymers of vinyl chloride, vinyl acetate, styrene, acrylonitrile, acrylic acid and/or methacrylic acid esters, butadiene, as well as copolymers of the monomers mentioned above, in particular ABS or EVA. Examples from the series of polyaddition and polycondensation resins are the condensation products of formaldehyde with phenols, phenolic resins, and the condensation products of formaldehyde with urea, thiourea and melamine, amino resins, polyesters, including not only saturated, for example alkyd resins, but also unsaturated, for example maleic resins, linear polyesters, polyamides and polycarbonates or silicones. These polymeric materials can be present individually or as mixtures, as plastic materials or melts which if desired can be spun into fibers. They can also be present in dissolved form as film formers or binders for lacquers, paints or printing inks, for example linseed oil varnish, nitrocellulose, alkyd resins, melamine resins and urea-formaldehyde resins or acrylic resins. The coloring of plastic or rubber compositions with bismuth-containing compositions is effected using known techniques, for example, by admixing a compound of this type, if desired in the form of a masterbatch, into the formulation using rolls or mixing or milling apparatus. The colored material is then brought into the desired final form by known processing techniques, such as calendaring, pressing, extmding, brushing, casting or injection molding. Frequently it is desirable, if non-rigid moldings are to be prepared or to reduce the brittleness thereof, to incor¬ porate plasticizers into the formulation before molding. Suitable plasticizers are, for example, esters of phosphoric acid, phthalic acid or sebacic acid. The plasticizers can be incorporated into the formulation before or after the incorporation of the bismuth-containing compositions into such formulations. It is further possible, for the purpose of obtaining different colors, to add to the formulation, in addition to the bismuth-containing compositions, fillers or other coloring constituents such as white, color or black pigments, in any desired amounts.

To color coating compositions such as paints and printing inks, the polymeric materials mentioned above and the bismuth-containing compositions, if desired together with additives, such as fillers, other pigments, siccatives or plasticizers, are finely dispersed or dissolved in a common organic solvent or solvent mixture or water. This can be done by dispersing or dissolving the individual components separately or together in groups, and then combining all the components. The ceramics that can be colored using the bismuth-containing compositions encompass a wide variety of engineering materials, other than metals and alloys, that are chemically inorganic and are rendered serviceable through high temperature processing. These ceramics are normally composed of both cationic and anionic species; their primary difference from other materials being in the nature of their chemical bonding. They are sometimes referred to as ionic solids, i.e., possessing ionic bonding. The ceramics that can be colored include, single crystals, polycrystalline materials, glass-bonded aggregates, insulating foams and wholly vitreous substances. These include glasses, glazes and porcelain or vitreous enamels. The raw materials used in making these ceramics are primarily clay, including shale and mudstone, silica, and feldspar. Other raw materials include a wide variety of rocks, minerals and synthetic compounds used to manufacture diverse products.

The clays are of three principal families: kaolinite,

montmoriUonite, X_yAl₂(Al_ySi ._y(O₁₀)(Ol__)₂ where X is usually Na, Mg, or Al, and illite, K_y(AlFeMg₄Mg)(Al_ySi_g._y)O₂₀(O__I)₄. Closely associated minerals are gibbsite, Al(OH)₃, diaspore, HAlO₂, and bauxite (of indefinite composition but usually given as AlA-2H₂O which is an intermediate between the first two). All clays have as the major constituents one or more of these minerals. The kaolinite group includes kaolinite, halloysite, dickite, and nacrite. The montmorillonite group includes montmorillonite, nontronite, beidellite, hectorite, and saponite. The illite group, similar to muscovite but containing less potassium, more silica, and more combined water, includes the illites, the hydromicas, phengite, brammallite, glaucomite, and celadonite. There is a wide range of substitutions that occur in each family. In addition, most clays have one or more accessory minerals, e.g., quartz, muscovite, biotite, limonite, hydrous micas, feldspar, vermiculate, and/or carbonaceous matter.

The clays that can be used are sometimes referred to by names that reflect their use. For example: a pottery clay is used to make pottery; a sewer-pipe clay is used for sewer pipe; fire-clays (or refractory clay) are used to manufacture fireclay bricks, crucibles, refractory mortars, etc.; china clay is used to manufacture whitewares; slip clays are used for glazing stoneware and porcelain; and brick clays are used to manufacture common brick and face brick.

The silica can be in the form of quartz, tridymite, cristobalite, vitreous silica, cryptocrystalline forms, hydrated silica, and diatomite. Sources of silica that are useful include sandstones, quartzites, and sands. Feldspars are used chiefly as fluxes and sources of Al₂O_3. SiO₂, alkalies (K₂O, Na₂O), and CaO. The plagioclase feldspars vary in composition from albite, NaAlSiA, to anorthite, CaAlySiA, in a continuous series of solid solutions. Orthoclase and microcline feldspar (KAlSi₃O_g) are referred to as potash feldspar. Anorthoclase, (Na,K)AlSi₃0₈, is a combination of albite and potash feldspar. High soda feldspars are used in glasses and glazes.

Other nonclay minerals include nepheline syenite, a rock that contains a large percentage of the mineral nephelite, (Na,K)₂Al₂Si₂O_g, along with some soda and potash feldspars; lime, derived by calcination of limestone chiefly calcium carbonate, CaCO₃, which is used in glazes, enamels, and glasses; magnesium silicates such as talc (used as a flux with clays), asbestos (used chiefly for insulating refractories), and olivine (used for refractory products; fluxing mirerals which lower the vitrification temperature, the melting temperature or the reaction temperature, e.g., lithium minerals spodumene, Li₂Al₂Si₄O₁₂, lepidolite, |K₂Li***Al₃)-

amblygonite, Li₂F₂Al₂PA. and petralite, IiAlSiAo_* as well as barium minerals such as barite, BaS0₄, and whiterite, BaCO₃; refractory minerals such as zirconium minerals, hydrated alumina minerals, titania, TiO₂, thoria, ThO*-., graphite, magnesite, dolomite, gypsum, chromite, the aluminum silicates, and pyrophyllite.

The forming methods used in the production of these ceramics include plastic deformation (e.g., extrusion, dry pressing and hot forming methods) and casting (e.g., slip and fusion casting). The compounds of Formulae I or II are blended with the other constituents of the ceramic formulation using conventional colorant or pigment blending techniques. In preparing materials for forming, optimal particle size and size distribution may be obtained by crushing and grinding the various materials, separating the various size fractions by screening, and thai blending the desired size fractions of each material. In cold forming, the ceramic ware is made oversize and shrinks during firing and drying. In hot forming (e.g. , hot pressing, hot extrusion, hot rolling, forging and swaging, hot isostatic pressing, and chemical vapor deposition), the ceramic ware is made close to its final size. Thermal treatment is an essential step in the manufacturing of these ceramics. Materials that are stable at room temperature have to be raised to relatively high temperatures (ranging from about 700" C for enamels to about 1650 "C for alumina ceramics) for reactions to take place. Thermal treatment is a smoothly varying time-temperature profile, rather than a particular temperature held for some time period. To determine firing temperature and quality control, thermocouples, radiation pyrometers, and optical pyrometers are used. Expendable pyrometric cones can be used for structural clay products, porcelains and sanitary ware. Microstructures and properties of many specialty ceramics vary according to time- temperature profile and often require precise monitoring of thermal gradients and temperature. Drying and binder removal generally occurs between about 0-400^* C. The ceramic loses physically held water and organic binders which are used in the forming operation. Firing occurs at higher temperatures, and involves these changes: dissociation, the loss of carbon dioxide by carbonate constituents of ceramic compositions; compound formation, the continued heating of clays which results in the formation of mullite, 3Al₂O₃ ^*2SiO₂; polymorphic transformation of materials capable of existing in more than one crystallographic arrangement, e.g., silica and zirconia; sintering, the fabrication of a product usually involving densification by pore removal through diffusional mechanisms; and vitrification. The porcelain enameling process involves the re-fusing of powdered glass on a metal surface. The powdered glass is prepared by ball-milling the desired porcelain enamel glass. The compounds of Formulae I or π are blended with the powdered glass using conventional blending techniques. The glass is smelted from raw batch materials. The smelter can be a box-shaped tank furnace. A continuous smelter, wherein the thoroughly mixed raw batch is fed in at one end and molten glass is flowing out at the other end, can be used. Decomposition, gas evolution, and solution occur during smelting. After the molten glass is smelted to a homogeneous liquid, it is poured in a thin stream of water or onto cooled metal rollers. This quenched glass, termed frit, is a friable material easily reduced to small particles by a ball-milling operation. Ball-milling the glass frit into small sized particles can be carried out whether the frit is wet or dry. Dry powders are used for dry-process cast- iron enameling and for electrostatic application on sheet steel. Dry powders are also prepared and marketed for the subsequent preparation of slurries and slips used in the wet-process application techniques. The bismuth-containing compositions are present in the colored compositions of the invention at a suitable level to provide the desired degree of coloring. These compounds are typically employed at concentration levels in the range of about 0.001% to about 40% by weight, more preferably about 0.01% to about 20% by weight based on the total weight of the colored compositions. The bismuth-containing compositions are characterized by good general pigment properties, such as good dispersibility, high tinctorial strength, purity, high hiding power, good overlacquering, migration, heat, light and weathering resistance, and good resistance to chemicals, such as acids, bases, organic solvents and industrial atmosphere. In addition they confer on the printing inks, paints and lacquers prepar¬ ed therefrom good rheological behavior, and on the dried films a high gloss.

The following examples are provided for purposes of exemplifying the invention. Unless otherwise indicated, in the following examples as well as through¬ out the specification and claims, all parts and percentages are by weight, all temperatures are in degrees centigrade, and all pressures are atmospheric.

Example 1

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 169.8 gms of Bi(NQj)₃'5H₂O and 7.9 gms of TiOSO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH and 29.3 gms of NI_₄VO₃ to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 'C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^* C. The fourth aqueous composition is maintained at 70 'C for three hours with ∑tirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition. Example 2 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40^* C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 169.8 gms of Bi(NQ₃)₃ ^a5H₂O to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 29.3 gms of NH₄V0₃ and 9.35 gms of SnCγ2H₂0 to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70' C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600^* C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 3 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40" C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70 'C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 169.8gms of Bi(NOj)₃ ^*5H₂O and 5.7 gms of TiOSO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 29.3 gms of NBVVO₃ and 3.1 gms Na₂MoO₄2H₂O to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600^* C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 4

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 169.8 gms of Bi(NQj)₃-5H₂O and 7.9 gms of TiOSO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 29.3 gms of NH A and 6.1 gms of Na₂MoO₄ ^*2H₂O to 350 ml of water.

The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of

70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^* C. The fourth aqueous composition is maintained at 70 ' C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition. Example 5 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70' C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 169.8 gms of Bi(NQj)₃-5H₂O and 1.9 gms of TiOS0₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 29.3 gms of

and 9.1 gms of Na₂Mo0₄'2H₂0 to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 6 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40^* C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 121.5 gms of Bi(Nqj)₃-5H₂0 and 15.3 gms of BaO to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 29.3 gms of M^VO, and 12.1 gms of Na2Mo0₄2H₂0 to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 "C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while m- ntaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 "C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 7

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 164 gms of Bi(NQ-,)₃ -5H₂O, 5.7 gms of TiOSO₄ and

3.1 gms of SrMoO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH and 29.3 gms of NHiVO*, to 350 ml of water.

70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70^*C. The fourth aqueous composition is maintained at 70^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 "C for one hour, cooled to ambient temperature and ground to provide the desired solids composition. Example 8 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40' C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70'C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi(NOj)₃'5H₂O to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH,V0₃ and 9.34 gms of SnO*v2H₂O to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 'C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 9 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40^* C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 40 ml of water, then adding 97.5 gms of Bi(NOj)₃ ^*5H₂O to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH A, 6.05 gms Na₂MoO₄2H₂O and 4.7 gms SnO₂2H₂O to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70" C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while n aintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 10 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70" C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi(NQ₃)₃-5H₂O to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of I. O₃ and 9.1 gms of Na₂MoO₄ ^*2H₂O and 2.4 gms of SnO*j^*2H₂O to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70^* C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 "C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600^* C for one hour, cooled to ambient temperature and ground to provide the desired solids composition. Example 11 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi(NO*₃)₃ ^*5H₂O and 8.0 gms of TiOSO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH and 11.7 gms of NH,V0₃ to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 'C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 12 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi(NQ₃)₃ ^*5H₂0 and 2.0 gms of TiOS0₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH-ΛA and 9.1 gms of Na₂MoO₄2H₂0 to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 2 hours with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 "C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70^*C. The fourth aqueous composition is maintained at 70"C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired solids composition.

Example 13

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40" C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi O₃)₃-5H₂O and 4.0 gms of TiOSO₄ to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH-VO₃ and 6.05 gms of Na₂Mo0₄2H₂0 to 350 ml of water.

70^* C. The pH of the fourth aqueous composition is increased to 2 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70^*C. The fourth aqueous composition is maintained at 70"C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 "C for one hour, cooled to ambient temperature and ground to provide the desired solids composition. Example 14 72.15 parts of Bi₂O₃. 24.32 parts of V₂0₅ and 3-5 parts of TiO₂ are mixed together. The mixture is heated to 600 ^*C over a period of 2 hours, maintained at 600 ^*C for 4 hours, heated to a temperature of 800 ^*C over a period of 2 hours, maintained at 800 ^* C for 12-16 hours, and then cooled to room temperature to provide the desired product.

Example 15

69.95 parts of Bi₂0_3» 23.58 parts of V₂O_s and 6.46 parts of SnO*; are mixed together. The mixture is heated to 600 "C over a period of 2 hours, maintained at 600^* C for 4 hours, heated to a temperature of 800^* C over a period of 2 hours, maintained at 800^* C for 12-16 hours, and then cooled to room temperature to provide the desired product.

Example 16

67.60 parts of Bi₂0₃, 22.79 parts of V₂0₅ and 9.61 parts of WC-₃ are mixed together. The mixture is heated to 600 ^* C over a period of 2 hours, maintained at 600 'C for 4 hours, heated to a temperature of 800-850 'C over a period of 2 hours, maintained at 800-850 ^*C for 12-16 hours, and then cooled to room temperature to provide the desired product.

Example 17 69.35 parts of Bi₂O_3» 27.25 parts of V₂O₅ and 3.40 parts of SnOj are mixed together. The mixture is heated to 600 ^*C over a period of 2 hours, maintained at 600 'C for 4 hours, heated to a temperature of 800 ^*C over a period of 2 hours, maintained at 800 ^*C for 12 hours, and then cooled to room temperature. The resulting product is ground using a mortar and pestle, heated to 850 'C for a period of 4 hours, then cooled to room temperature to provide the desired product.

Example 18

74.75 parts of Bi₂0₃» 22.05 parts of V₂0₅ and 3.20 parts of Ti0₂ are mixed together. The mixture is heated to 600" C over a period of 2 hours, maintained at 600 ^*C for 4 hours, heated to a temperature of 800 ^*C over a period of 2 hours, maintained at 800 ^*C for 12 hours, and then cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 4 hours, then cooled to room temperature to provide the desired product.

Example 19 72.15 parts of Bi₂0₃. 20.43 parts of V₂O₅ and 7.42 parts of TiOj are mixed together. The mixture is heated to 600 ' C over a period of 2 hours, maintained at 600 "C for 2 hours, heated to a temperature of 800 "C over a period of 2 hours, maintained at 800^* C for 12 hours, and then cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 "C for 4 hours, then cooled to room temperature to provide the desired product.

Example 20 74.31 parts of Bi₂O₃, 21.21 parts of V₂O₅. 1-68 parts of MoO₃ and 2.80 parts of TA are mixed together. The mixture is heated to 600^*C over a period of 2 hours, maintained at 600^*C for 2 hours, heated to 800"C over a period of 2 hours, maintained at 800 ^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 12-16 hours, then cooled to room temperature to provide the desired product. Example 21

72.52 parts of Bi₂O₃, 20.70 parts of V₂O₅, 1.64 parts of MoO₃ and 5.15 parts of SnC**. are mixed together. The mixture is heated to 600 " C over a period of 2 hours, maintained at 600 'C for 2 hours, heated to 800 ^*C over a period of 2 hours, maintained at 800 'C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 12-16 hours, then cooled to room temperature to provide the desired product.

Example 22 75.12 parts of Bi₂O₃, 23.04 parts of V₂O₅, and 1.84 parts of TiO₂ are mixed together. The mixture is heated to 600^* C over a period of 2 hours, maintained at 600^*C for 2 hours, heated to 800^*C over a period of 2 hours, maintained at 800^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 12-16 hours, then cooled to room temperature to provide the desired product. Example 23

73.92 parts of Bi₂O₃, 22.67 parts of V₂O_5. and 3.41 parts of SnO₂ are mixed together. The mixture is heated to 600 ' C over a period of 2 hours, maintained at 600^*C for 2 hours, heated to 800^*C over a period of 2 hours, maintained at 800^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 12-16 hours, then cooled to room temperature to provide the desired product.

Example 24 73.28 parts of Bi₂O₃. 21.44 parts of V₂O₅, 3.39 parts of MoO₃ and 1.88 parts of TiO₂ are mixed together. The mixture is heated to 600 ^*C over a period of 2 hours, maintained at 600 ^*C for 2 hours, heated to 800 ^*C over a period of 2 hours, maintained at 800 ^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 'C for 4 hours, then cooled to room temperature to provide the desired product. Example 25

75.70 parts of Bi₂O₃» 16.88 parts of V₂O₅, and 7.42 parts of TiO₂ are mixed together. The mixture is heated to 600 ^*C over a period of 2 hours, maintained at 600^*C for 2 hours, heated to 800^*C over a period of 2 hours, maintained at 800^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 850 ^*C over a period of 4 hours, maintained at 850 ^*C for 4 hours, then cooled to room temperature to provide the desired product.

Example 26 72.24 parts of Bi₂O₃, 21.67 parts of V₂O₅, 5.14 parts of Mo0₃ and 0.95 parts of Ti0₂ are mixed together. The mixture is heated to 600 "C over a period of 2 hours, maintained at 600 ^*C for 2 hours, heated to 800 ^*C over a period of 2 hours, maintained at 800^* C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 800 'C over a period of 4 hours, maintained at 800 ^*C for 4-8 hours, then cooled to room temperature to provide the desired product. Example 27

72.08 parts of Bi₂O₃» 21.09 parts of V₂O₅» 3.34 parts of MoO₃ and 3.49 parts of SnO₂ are mixed together. The mixture is heated to 600" C over a period of 2 hours, maintained at 600 "C for 2 hours, heated to 800 "C over a period of 2 hours, maintained at 800 "C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 800 ^*C over a period of 4 hours, maintained at 800 'C for 4-8 hours, then cooled to room temperature to provide the desired product.

Example 28

71.63 parts of Bi₂O₃, 21.49 parts of V₂O_5. 5.10 parts of MoO₃ and 1.78 parts ofSnO₂ are mixed together. The mixture is heated to 600 'C over a period of 2 hours, maintained at 600 'C for 2 hours, heated to 800 "C over a period of 2 hours, maintained at 800 ^*C for 12 hours, and cooled to room temperature. The resulting product is ground using mortar and pestle, heated to 800 ^*C over a period of 4 hours, maintained at 800 ^*C for 4-8 hours, then cooled to room temperature to provide the desired product.

Example 29 18.3 parts of Bi₂O₃, 6.6 parts of V₂O₅ and 3.2 parts of SbA are mixed together. The mixture is heated to 600 "C over a period of 2 hours, maintained at 600 ^*C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 750 ^*C for 10 hours and cooled to room temperature. The resulting product is ground, heated at 800 "C for 10 hours, then cooled to room temperature. The resulting product is ground, heated to 850" C for 4 hours, then cooled to room temperature to provide the desired product. Example 30 18.3 parts of Bi₂O₃, 6.6 parts of V₂O₅ and 2.9 parts of Nb₂O₅ are mixed together. The mixture is heated to 600 ^* C over a period of 2 hours, maintained at 600 "C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 750 'C for 10 hours and cooled to room temperature. The resulting product is ground, heated at 800 ^*C for 10 hours, then cooled to room temperature. The resulting product is ground, heated to 850 'C for 4 hours, then cooled to room temperature to provide the desired product.

Example 31 18.3 parts of Bi₂O₃, 6.6 parts of V₂O₅ and 4.9 parts of Ta₂O₅ are mixed together. The mixture is heated to 600^* C over a period of 2 hours, maintained at 600 "C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 750 ^*C for 10 hours and cooled to room temperature. The resulting product is ground, heated at 800^* C for 10 hours, then cooled to room temperature. The resulting product is ground, heated to 850 ^*C for

4 hours, then cooled to room temperature to provide the desired product.

Example 32 19.3 parts of Bi₂0₃, 5.5 parts of V₂O₅ and 5.2 parts of SbA are mixed together. The mixture is heated to 600 "C over a period of 2 hours, maintained at 600 ^*C for 2 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 800 'C for 2 hours and cooled to room temperature. The resulting product is ground, heated at 900 ^*C for 10 hours, then cooled to room temperature to provide the desired product.

Example 33 19.4 parts of Bi₂O₃, 6.5 parts of V₂O₅ and 4.0 parts of SbA are mixed together. The mixture is heated to 600 'C over a period of 2 hours, maintained at 600 ^*C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 800 ^*C for 2 hours and cooled to room temperature. The resulting product is ground, heated at 900 "C for 10 hours, then cooled to room temperature to provide the desired product. Example 34

19.5 parts of Bi₂O₃, 7.1 parts of V₂O₅ and 3.3 parts of SbA are mixed together. The mixture is heated to 600 ^*C over a period of 2 hours, maintained at 600 ^*C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 800 ' C for 2 hours and cooled to room temperature.

The resulting product is ground, heated at 900 'C for 10 hours, then cooled to room temperature to provide the desired product.

Example 35

19.6 parts of Bi₂O₃, 7.9 parts of V₂O₅ and 2.4 parts of SbA are mixed together. The mixture is heated to 600 'C over a period of 2 hours, maintained at

600 ^* C for 50 hours and cooled to room temperature. The resulting product is ground using mortar and pestle, heated at 800 ^*C for 2 hours and cooled to room temperature. The resulting product is ground, heated at 900^* C for 10 hours, then cooled to room temperature to provide the desired product. Example 36

A first aqueous composition is prepared by adding 10 ml of 1:1 nitric acid to 460 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 1.0. The first aqueous composition is heated to 70' C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 300 ml of water, then adding 97.5 gms of Bi(NO*,)₃-5H₂O to the resulting solution.

A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH_tVO-j and 12.1 gms of Na₂MoO₄ ^*2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 40 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.8 and a temperature of 70^*C. The pH of the fourth aqueous composition is increased to 1.0 by the addition of an NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for two hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 'C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate-containing composition.

Example 37 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The temperature of the water is 40 ^*C. The first aqueous composition has a pH of 0.8. The first aqueous composition is heated to 70'C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 300 ml of water, then adding 97.5 gms of Bi(Nθ₃)₃5H₂0 to the resulting solution. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NI-VVO**, and 12.2 gms of Na₂MoO₄ ^*2H₂O to 350 ml of water. The second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 55 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 'C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 38 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 400 ml of water, then adding 68.4 gms of Bi(NO*,)₃5H₂0 to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH«V0₃ and 4.8 gms of Na₂MoO 2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 55 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 70 ^* C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 70 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 'C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium- molybdate containing solids composition.

Example 39 A first aqueous composition is prepared by adding 20 ml of 1: 1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 300 ml of water, then adding 78.19 gms of Bi(Nθ₃)₃'5H₂0 to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition.

The second aqueous composition has a pH of 0.3. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH A and 7.26 gms of

Na₂Mo0 ^*2H₂0 to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The third aqueous composition has a pH of 13. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 55 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 73.3 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 35 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70 ^*C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated to a temperature of 600^*C over a period of 1.5 hours, maintained at 600'C for 2 hours, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 40 A first aqueous composition is prepared by adding 20 ml of 1: 1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 400 ml of water, then adding 87.8 gms of Bi(N0₃)₃'5H₂O to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. The pH of the second aqueous composition is 0.3. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH-ΛA and 9.68 gms of Na₂Mo0₄ ^*2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The pH of the third aqueous composition is 14. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition are simultaneously added to the first aqueous composition over a period of one hour with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 70^* C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 75 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of one hour while mamtaining the temperature of the fourth aqueous composition at 70^* C. The fourth aqueous compo¬ sition is maintained at 70^* C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 "C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 41 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70 "C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 97.5 gms of Bi(N0₃)₃ ^*5H₂O to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms

and 12.1 gms of Na₂MoO₄ ^*2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of one hour with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 1.4 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 70.5 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 45 minutes while maintaining the temperature of the fourth aqueous composition at 70 "C. The fourth aqueous compo¬ sition is maintained at 70 "C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated to a temperature of 600 ^*C over a period of one hour, maintained at 600 ^*C for one hour, and cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 42 A first aqueous composition is prepared by adding 10 ml of 1:1 nitric acid to 460 ml of water. The first aqueous composition has a pH of 1.0. The first aqueous composition is heated to 70 ^*C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 280 ml of water, then adding 97.5 gms of Bi(NO₃)₃-5H₂O to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 350 ml for said composition. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH_JVO-_J and 12.1 gms of Na₂Mo0₄2H₂0 to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 40 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.8 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 1.0 by the addition of 45.5 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) while maintaining the temperature of the fourth aqueous composition at 70 ^* C. The fourth aqueous composition is maintained at 70 ^* C for two hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition. Example 43

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70" C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 400 ml of water, then adding 107.2 gms of Bi(N0₃)₃5H₂0 to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of H A and 14.52 gms of Na₂MoO₄2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of one hour with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.5 and a temperature of 70 "C. The pH of the fourth aqueous composition is increased to 2.2 by the addition of 89.8 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 50 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^*C. The fourth aqueous composition is maintained at 70" C for two hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example -44 A first aqueous composition is prepared by adding 20 ml of 1: 1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 75 ^*C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 400 ml of water, then adding 121.8 gms of BifNOs SB-jO to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. The second aqueous composition has a pH of 0.3. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH_*VO₃ and 18.5 gms of Na₂MoO₄ ^*2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The pH of the third aqueous composition is 13. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 55 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 75 ^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 91 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 50 minutes while maintaining the temperature of the fourth aqueous composition at 75 "C. The fourth aqueous composition is maintained at 75 'C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 45 A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition is heated to 72 ^*C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 400 ml of water, then adding 146 gms of Bi(NO**-)₃-5H₂O to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NHjVO*, and 24.2 gms of Na₂Mo0₄'2H₂0 to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 55 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.4-0.6 and a temperature of 72^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 96.4 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 40 minutes while maintaining the temperature of the fourth aqueous composition at 72 ^* C. The fourth aqueous composition is maintained at 72 ^* C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition. Example 46

A first aqueous composition is prepared by adding 20 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 0.5. The first aqueous composition is heated to 70^* C. A second aqueous composition is prepared by adding 50 ml of concentrated nitric acid to 400 ml of water, then adding 267.3 gms of Bi(N0₃)₃5H₂0 to the resulting solution. Additional water is added to the second aqueous composition to provide a volume of 500 ml for said composition. The second aqueous composition has a pH of 0.3. A third aqueous composition is prepared by adding 20 gms of NaOH, 11.7 gms of NH,V0₃ and 54.4 gms of Na₂MoO .2H₂O to 300 ml of water. Additional water is added to the third aqueous composition to provide said composition with a volume of 350 ml. The third aqueous composition has a pH of 13. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of one hour with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 2.0 by the addition of 155 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 70 minutes while maintaining the temperature of the fourth aqueous composition at 70 ^* C. The fourth aqueous composition is maintained at 70 ^* C for three hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 ^*C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition. Example 47 A first aqueous composition is prepared by adding 10 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 1.0. The first aqueous composition is heated to 70 "C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 300 ml of water, then adding 98.5 gms ofBi(NO₃)₃ ^*5H₂O to the resulting solution. A third aqueous composition is prepared by adding 16 gms of NaOH (50% by weight aqueous solution), 18.4 gms of Na₃V0₄ and 12.1 gms of Na₂Mo0₄2H₂0 to 350 ml of water. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of one hour with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.6 and a temperature of 70^*C. The pH of the fourth aqueous composition is increased to 1.0 by the addition of 46 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 13 minutes while maintaining the temperature of the fourth aqueous composition at 70-72 ^*C. The fourth aqueous composition is maintained at 55-70 ^*C for two hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 "C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

Example 48 A first aqueous composition is prepared by adding 10 ml of 1:1 nitric acid to 450 ml of water. The first aqueous composition has a pH of 1.0. The first aqueous composition is heated to 70' C. A second aqueous composition is prepared by adding 46 ml of concentrated nitric acid to 300 ml of water, then adding 96.0 gms of Bi(N0₃)₃ ^*5H₂0 to the resulting solution. A third aqueous composition is prepared by adding 16 gms of NaOH, 12.2 gms of NaVC*, and 12.1 gms of Na₂Mo0₄-2H₂0 to 350 ml of water. The first aqueous composition is stirred and the second aqueous composition and the third aqueous composition are simultaneously added to the first aqueous composition over a period of 65 minutes with the result being the formation of a fourth aqueous composition. The fourth aqueous composition comprises precipitated solids and has a pH of 0.5 and a temperature of 70 ^*C. The pH of the fourth aqueous composition is increased to 4.0 by the addition of 74 ml of a NaOH solution (50 gms of NaOH dissolved in 100 ml of water) over a period of 20 minutes while mamtaining the temperature of the fourth aqueous composition at 70-72 ^*C.

The fourth aqueous composition is maintained at 70 'C for two hours with stirring. The precipitated solids in the fourth aqueous composition are separated out using filtration, washed and then dried. The dried solids are heated at a temperature of 600 'C for one hour, cooled to ambient temperature and ground to provide the desired bismuth-vanadium-molybdate containing solids composition.

While the invention has been explained in relation to its preferred embodiments, it is to be understood that various modifications thereof will become apparent to those skilled in the art upon reading the specification. Therefore, it is to be understood that the invention disclosed herein is intended to cover such modifications as fall within the scope of the appended claims.

Claims

1. A colored composition comprising a material capable of being colored and an effective amount of at least one colorant to impart color to said material, said colorant comprising at least one compound represented by the formula Bi- .AO_y wherein

A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof;

D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; with the proviso that when A is Bi, D is other than a mixture consisting of V and Mo.

2. The composition of claim 1 wherein x is a number in the range of 1 to about 10.

3. The composition of claim 1 wherein A is Bi, Ba, Sr, Ca, Y, La or a mixture of two or more thereof.

4. The composition of claim 1 wherein A comprises Bi.

5. The composition of claim 1 wherein D is selected from the group consisting of (1) Ti, Sn, Ce, Mo, W or a mixture of two or more thereof; (2)

V, Cr, Nb, Sb, Ta, Fe or a mixture of two or more thereof; and (3) V, Mo, Ti, Sn or a mixture of two or more thereof.

6. The composition of claim 3 wherein D is selected from the group consisting of V, Mo, Ti, Sn or a mixture of two or mere thereof.

7. The colored composition of claim 1 wherein A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof;

D is selected from the group consisting of Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D.

8. The colored composition of claim 1 wherein A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; D is selected from the group consisting of V. Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn,

Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D.

9. The composition of any one of claims 1-6 and 15-17 wherein said colorant is in the form of particulate solids, and, optionally said solids being coated with an inorganic protective coating.

10. The composition of any one of claims 1-6 and 15-17 wherein said colorant is in the form of particulate solids, said solids being coated with a coating of silica, and a coating of wax overlying said coating of silica.

11. The composition of any one of claims l-6and 15-17in the form of a plastic or rubber composition.

12. The composition of any one of claims 1-6 and 15-17 in the form of a coating composition which when applied to a substrate as a thin layer is converted to a solid protective, decorative or functional adherent film.

13. The composition of any cne of claims 1-6 and 15-17 in the form of paint or printing ink.

14. The composition of any one of claims 1-6 and 15-17 with about 0.001% to about 40% by weight of said colorant.

15. The composition of any one of claims 1-6 and 15-17 wherein said colorant has a composition within the quadrilateral I-E-HI-IV of Figs. 1, 2, 3 or 4; or the quadrilateral V-VI-Vπ-VHI of Fig. 4.

16. A process for making a colored composition comprising incorporating into a material capable of being colored an effective amount of at least one colorant of any one of claims 1-6 and 15-17 to impart color to said material.

17. The colored composition of claim 1 wherein A is a mixture consisting of Bi and one or more of Ba, Sr, Ca, Y or La; D is a mixture consisting of V and Mo; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D.

18. A colored composition comprising a material capable of being colored and an effective amount of at least one colorant to impart color to said material, said colorant comprising at least one crystalline stmcture represented by the formula

wherein said crystalline stmcture comprises one or more layers of (A_n-iDA_n+i)^2" stacked between layers of (Bi₂θ₂)²⁺; n is the number of layers of

stacked between layers of (B_A)²⁺ and is at least 1;

A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; and D is selected from the group consisting of V, Mo, Mn, Ti, Ta,

Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; with the proviso that when A is Bi, D is other than a mixture consisting of V and Mo.

19. A process for making a bismuth-containing composition represented by the formula

Bi₂A_x.,D_xO_y wherein

A is selected from the group consisting of Bi, Ba, Sr, Ca, Y, La, or a mixture of two or more thereof; D is selected from the group consisting of V, Mo, Mn, Ti, Ta,

Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; said process comprising the steps of: (A) preparing a^first aqueous composition having a pH in the range of about 0.5 to about 5;

(B) preparing a second aqueous composition comprising at least one salt of bismuth or bismuth metal and, optionally at least one salt of component A or metallic A, and having a pH in the range of about 0.2 to about

5;

(C) preparing a third aqueous composition comprising at least one salt of D or metallic D; with the proviso that if A is not present or if A consists solely of Bi, D is other than a mixture consisting solely of V and Mo; said third aqueous composition having a pH that is less acidic than said second aqueous composition;

(D) adding said second aqueous composition and said third aqueous composition simultaneously to said first aqueous composition to form a fourth aqueous composition comprising precipitated solids comprising Bi, D and optionally A;

(E) maintaining said fourth aqueous composition from (D) at a temperature in the range of about 25 ^*C to about 70 ^*C for up to about 3 hours;

(F) deliquifying said fourth aqueous composition from (E) to provide deliquified solids; and (G) heating said deliquified solids from (F) at a sufficient temperature and for an effective period of time to provide said bismuth-con¬ taining composition.

20. The process of claim 19 wherein subsequent to step (D) but prior to step (E) an effective amount of at least one base is added to said fourth aqueous composition to increase the yield of precipitated Bi.

21. The process of claim 19 with the step of washing and drying said deliquified solids subsequent to step (F) but prior to step (G).

22. The process of claim 19 wherein said first aqueous composition has a pH in the range of about 1 to about 4; wherein said second aqueous composition has a pH in the range of about 0.5 to about 4; and wherein said fourth aqueous composition has a pH in the range of about 0.5 to about 6.

23. The process of claim 19 wherein said first aqueous composition has a temperature in the range of about 25 'C to about 90 "C; wherein said second aqueous composition has a temperature in the range of about

25 'C to about 70 ^*C; wherein said third aqueous composition has a temperature in the range of about 25 'C to about 90 "C; and wherein said fourth aqueous composition has a temperature in the range of about 25 ^*C to about 90 ^*C during step (D).

24. The process of claim 19 wherein the concentration of bismuth in said second aqueous composition is in the range of about 0.25 to about 4 gram-moles per liter; wherein the concentration of A in said second aqueous composition is up to about 1.5 gram-moles per liter; and wherein the concentration of D in said third aqueous composition is in the range of about 0.1 to about 4 gram-moles per liter.

25. The process of claim 19 wherein during step (G) the temperature of said solids is increased to a peak temperature in the range of about 525 ^*C to about 950 ^*C over a period of about 1 minute to about 10 hours, maintained at said peak temperature for about 1 to about 20 hours, and cooled to ambient temperature.

26. The process of claim 19 wherein during step (G) the temperature of said solids is increased to an intermediate temperature in the range of about 450 ^*C to about 550 ^*C over a period of about 1 to about 4 hours, maintained at said intermediate temperature for about 1 to about 4 hours, increased to a peak temperature in the range of about 600 ^* C to about 700 ^* C over a period of about 1 to about 4 hours, maintained at said peak temperature for about 1 to about 10 hours, and cooled to ambient temperature.

27. The process of any one of claims 20-29 with the additional step of heating said bismuth-containing composition from (G) at a temperature in the range of about 525 ^*C to about 950 ^*C for about 1 to about 10 hours.

28. The process of any one of claims 20-29 with the step of applying an inorganic protective coating to said bismuth-containing composition from step (G).

29. The process of any one of claims 20-29 with the steps of applying an inorganic protective coating to said bismuth-containing composition from step (G) to form a coated composition, and applying at least one coating of at least one texture-improving agent to said coated composition.

30. The process of any one of claims 20-29 with the steps of applying a coating of silica to said bismuth-containing composition from step (G) to form a coated composition, and optionally applying at least one coating of at least one wax to said coated composition.

31. A process for making bismuth-containing composition represented by the formula

wherein

D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of tv?o or more thereof; x is a number that is at least 1; nd y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; said process comprising the steps of:

(A') preparing a mixture comprising metallic Bi or at least one compound of Bi, metallic D or at least one compound of D and optionally metallic A or at least one compound of A; with the proviso that if A is not present or if A consists solely of Bi, D is other than a mixture consisting solely of V and Mo; (B') increasing the temperature of said mixture from (A') to an intermediate temperature in the range of about 550 ^*C to about 625 'C over a period of up to about 4 hours;

(C) maintaining the temperature of said mixture at said intermediate temperature for about 1 to about 10 hours;

(D') increasing the temperature of said mixture from said intermediate temperature to a peak temperature in the range of about 650 ^*C to about 950 ^*C over a period of up to about 4 hours;

(E') maintaining the temperature of said mixture at said peak temperature for about 1 to about 20 hours; and

(F') cooling said mixture from (E') from said peak temperature to ambient temperature to provide said bismuth-containing composition.

32. The process of claim 31 wherein said compound of A is an oxide, carbonate, hydroxide, oxalate or nitrate, and wherein said compound of D is an oxide, carbonate, hydroxide, oxalate or nitrate.

33. The process of claim 31 wherein during step (B') said temperature is increased to said intermediate temperature over a period of about

1 to about 3 hours; wherein during step (C) said temperature of said mixture is maintained at said intermediate temperature for about 2 to about 6 hours; wherein during step (D') said temperature is increased to said intermediate peak temperature over a period of about 1 to about 3 hours; wherein during step (E') said temperature of said mixture is maintained at said peak temperature for about

2 to about 6 hours; and wherein during step (F') said temperature is cooled from said peak temperature to ambient temperature over a period of about 8 to about 24 hours.

34. The process of any one of claims 35-38 with the additional step of heating said bismuth-containing composition from (F') at said peak temperature for about 1 to about 10 hours.

35. The process of any one of claims 35-38 with the additional steps of applying an inorganic protective coating to said bismuth-containing composition to form a coated composition, and optionally applying at least one coating of at least one texture-improving agent to said coated composition.

36. The process of any one of claims 35-38 with the additional steps of applying a coating of silica to said bismuth-containing composition to form a coated composition, and optionally applying at least one coating of at least one wax to said coated composition.

37. A process for making bismuth-containing composition represented by the formula

wherein

D is selected from the group consisting of V, Mo, Mn, Ti, Ta, Nb, W, Sb, Fe, Cr, Sn, Ce, or a mixture of two or more thereof; x is a number that is at least 1; and y is the number of oxygens needed to fulfill the valence requirements of Bi, A and D; said process comprising the steps of:

(A") preparing a mixture comprising metallic Bi or at least one compound of Bi, metallic D or at least one compound of D and optionally metallic A or at least one compound of A; with the proviso that if A is not present or if A consists solely of Bi, D is other than a mixture consisting solely of V and Mo;

(B") increasing the temperature of said mixture from (A") to a peak temperature in the range of about 500 ^*C to about 700 "C over a period of up to about 4 hours;

(C") maintaining the temperature of said mixture at said peak temperature for about 1 to about 60 hours; and

(D") cooling said mixture from (C") from said peak temperature to ambient temperature to provide said bismuth-containing composition.

38. A process for making a bismuth-vanadium-molybdenum- containing composition comprising:

(A*) preparing three separate aqueous compositions comprising: a first aqueous composition having a pH in the range of about 0.5 to about 4; a second aqueous composition comprising bismuth and having a pH in the range of about 0.2 to about 3; and a third aqueous composition comprising at least one salt of vanadium and at least one salt of molybdenum and having a pH in the range of about 9 to about 14;

(B*) adding said second aqueous composition and said third aqueous composition simultaneously to said first aqueous composition to form a fourth aqueous composition, and maintaining said fourth aqueous composition at a temperature in, the range of about 30 ^*C to about 90 ^*C for up to about 4 hours, said fourth aqueous composition comprising precipitated solids;

(C*) separating said solids from said fourth aqueous composition; and

(D*) heating said solids at a temperature in the range of about 250 ^*C to about 675 ^*C for about 0.5 to about 30 hours to provide said bismuth- vanadium-molybdenum-containing composition.

39. The process of claim 38 wherein during step (B*) an effective amount of at least one base is added to said fourth aqueous composition to increase the yield of bismuth in said precipitated solids.

40. The process of claim 38 with the step of washing and drying said solids from step (C*).

41. The process of claim 38 wherein said first aqueous composition has a pH in the range of about 0.5 to about 1.5; wherein said second aqueous composition has a pH in the range of about 0.2 to about 2; wherein said third aqueous composition has a pH in the range of about 10 to about 14; and wherein said fourth aqueous composition has a pH in the range of about 0.5 to about 6.

42. The process of claim 38 wherein said first aqueous composition has a temperature in the range of about 30 ^*C to about 90 ^*C; wherein said second aqueous composition has a temperature in the range of about 30^*C to about 50^*C; wherein said third aqueo-is composition has a temperature in the range of about 30"C to about 70^*C; and wherein said fourth aqueous composition has a temperature in the range of about 50^*C to about 80^*C during step (B*).

43. The process of claim 38 wherein the concentration of the bismuth in said second aqueous composition is in the range of about 50 to about 800 gms/liter; wherein the concentration of the vanadium in said third aqueous composition is in the range of about 5 to about 200 gmsliter; and wherein the concentration of the molybdenum in said third aqueous composition is in the range of about 1 to about 100 gms liter.

44. The process of claim 38 wherein the mole ratio of vanadium to molybdenum in said third aqueous composition is in the range of about 11:1 to about 2:1.

45. The process of any one of claims 43-39 wherein during step (D*) the temperature of said solids is increased to a peak temperature in the range of about 525 ^*C to about 675 ^*C over a period of about 1 minute to about 4 hours, maintained at said peak temperature fcr about 1 to about 10 hours, and cooled to ambient temperature.

46. The process of any one of claims 43-49 wherein during step (D*) the temperature of said solids is increased to an intermediate temperature in the range of about 250 ^*C to about 450 ^*C over a period of about 1 minute to about 4 hours, maintained at said intermediate temperature for about 1 to about

10 hours, increased to a peak temperature in the range of about 525 ^*C to about 675 ^*C over a period of about 1 minute to about 4 hours, maintained at said peak temperature for about 1 to about 10 hours, and cooled to ambient temperature.

47. The process of any one of claims 43-49 with the additional step of heating said bismuth-vanadium-molybdenum-containing composition from (D*) at a temperature in the range of about 525 'C to about 675 ^*C for about 1 to about 10 hours.

48. The process of any one of claims 43-49 with the steps of applying an inorganic protective coating to said bismuth-vanadium-molybdenum- containing composition from step (D*) to form a coated composition, and optionally applying at least one coating of at least one texture-improving agent to said coated composition.

49. The process of any one of claims 43-49 with the steps of applying a coating of silica to said bismuth-vanadium-molybdenum-containing composition from step (D*) to form a coated composition, and optionally applying at least one coating of at least one wax to said coated composition.

50. The process of any one of claims 43-49 wherein a bismuth salt is used, said salt of bismuth comprises Bi(NO₃)₃5H₂O; wherein said salt of vanadium comprises NH^VO*,, Na₃VO₄, NaV0₃ or a mixture of two or more thereof; and wherein said salt of molybdenum comprises an alkali metal molybdate.

51. The process of any one of claims 43-49 wherein said salt of molybdenum comprises Na₂MoO₄ ^*2H₂O.

52. The process of any one of claims 43-49 wherein said bismuth-vanadium-molybdenum-containing composition is represented by the formula

Bi.VbMo wherein: a is a number in the range of about 2 to about 11; b is a number in the range of about 0.7 to about 10; c is a number in the range of about 0.08 to about 4; and d is the number of oxygens needed to fulfill the valence requirements of

Bi, V and Mo.

53. The process of any one of claims 43-49 wherein said bismuth-vanadium-molybdenum-containing composition has a composition within the quadrilateral I-π-HI-IV of Fig. 5, or a composition within the quadrilateral V-VI-Vπ-Vm of Fig. 5.

54. The process of any one of claims 43-54 wherein said first aqueous composition comprises nitric acid, said second aqueous composition comprises bismuth nitrate and nitric acid, and said third aqueous composition comprising ammonium metavandate, at least one alkali metal salt of molybdenum and at least one alkali metal hydroxide.

55. A bismuth-vanadium-molybdenum-containing composition made by the process of any one of claims 43-59.

56. A colored composition comprising a material capable of being colored and an effective amount of at lea?t one colorant to impart color to said material, said colorant comprising at least one bismuth-vanadium- molybdenum-containing composition made by the process of any one of claims 43-59 comprising: