Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/10—Compounds of cadmium
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/04—Compounds of zinc
  • C09C1/06—Lithopone
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/10—Compounds of cadmium
  • C09C1/12—Cadmium sulfoselenide
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK  ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
  • C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
  • C09C1/38—Compounds of mercury
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/30—Three-dimensional structures
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data

Definitions

• One method involves heating the crude, usually in a non-oxidizing atmosphere, at elevated temperatures of about 400 to 700 C. (the so-called calcination treatment).
• Another method concerns heating the crude under pressure in aqueous medium in the presence of a small quantity of an alkaline-reacting salt at elevated temperatures and preferably at about 360 C.
• Still another method relates to heating an aqueous slurry of crude cadmium sulfo-selenide in the presence of 1,000 to 2,000 percent of an alkali metal hydroxide and 50 to 150 percent of an alkali or alkaline earth metal nitrate, sulfate, halide or aluminate at 90 to 160 C. It has also been proposed to purify compounds of Groups [l8 and VlA by heating the compounds in a water slurry of an alkaline earth halide in a flow of inert gas in a furnace at about l,000 C. until the impurities have reacted with the halide and been removed by the gas. These prior art treatments require high tempera tures, high temperatures and pressures or large amounts of alkali to promote the crystal growth and particle size development necessary for a good pigment. Thus, any advantages in lower processing conditions are offset by the high investments required for equipment, maintenance and recovery of chemicals.
• the present invention relates to a process for producing crystalline sulfides, selenides or solid solutions of sulfides and selenides of cadmium, zinc or mercury, which process comprises treating a crude, essentially amorphous precipitate of at least one sulfide, selenide or mixture of sulfides and selenides of cadmium, zinc or mercury with sufficient of an aqueous ammonium sulfide solution to provide a weight ratio of solution to precipitate of at least 1:] and a weight ratio of ammonium sulfide to precipitate of at least 0.02:1 until the precipitate is converted to the well-ordered hexagonal crystalline state, and then recovering the crystalline product so produced.
• the process of the invention have been found to be applicable to any Group "B sulfide, selenide or mixture of sulfides and selenides and is of particular value when applied to the cadmium sulfide-containing precipitates.
• the invention is particularly useful for refining cadmium sulfide, mixtures of cadmium sulfide and cadmium selenide, mixtures of cadmium sulfide and zinc sulfide and mixtures of cadmium sulfide and mercury sulfide.
• the invention is also useful for aging the pure cadmium pigments as well as the extended pigments such as those of the so-,called lithopone type.
• the crude, essentially amorphous precipitates which are treated in accordance with the invention can be prepared by any of the known methods for producing the desired crude precipitates of cadmium, zinc or mercury sulfides, selenides or mixtures of sulfides and selenides, as for example by reacting aqueous solutions or suspensions of salts of cadmium, zinc and/or mercury with solutions of an alkali metal or alkaline earth metal sulfide and/or selenide.
• the cadmium, zinc or mercury salt is a nitrate, sulfate or halide.
• the method of the invention is a wet conversion process in which crude, amorphous precipitates of at least one sulfide, selenide or mixture of sulfides and selenides of cadmium, zinc or mercury are treated in the presence of aqueous ammonium sulfide until the precipitate is converted to the wellordered crystalline state which exhibits by x-ray diffraction a welldeveloped hexagonal crystal structure.
• the treatment can be carried out at any convenient temperature but will usually be conducted within the range of from about 0 C. to about 300 C. and preferably from about 20 C. to about 275 C. for periods of time ranging from less than about 1 hour up to several days or more.
• the amount of ammonium sulfide solution which is used in the practice of the invention is an amount sufficient to provide a weight ratio of solution to precipitate (dry crude) of at least 1:1 and a weight ratio of ammonium sulfide ((Nl-l S) to precipitate of at least 0.02:1.
• the ratio of solution to precipitate will range from 1.521 to 20:1 and most preferably from 2:1 to 10:1
• the ratio of ammonium sulfide to precipitate will range from 0.05:1 to 15:1 and most preferably from 0.1:1 to 10:1.
• the concentration of the ammonium sulfide in the treating solution can vary within relatively wide limits and usually will range from about 2 percent to about percent and preferably from about 5 percent to about 50 percent by weight of solution.
• Other ammonium salts and particularly such salts as the nitrates, sulfates or halides can also be present in the treating solution in varying amounts providing they do not detract from the advantages of the invention.
• the amount of such other salts used will usually vary from about 5 percent to about 25 percent by weight of the treating solution.
• the crude precipitate which is treated in accordance with this invention can be freshly formed precipitate in the aqueous medium in which it is formed, a filter cake or press cake of the precipitate, or precipitate which has been filtered, washed and, if desired, dried and pulverized.
• the treatment of the invention does not require agitation, grinding, milling, etc. However, such can be used, if desired, to insure intimate contact and to facilitate handling.
• the products produced in accordance with the invention are crystalline, highly colored materials.
• cadmium sulfide-containing materials in particular are characterized by a broad range of properties exhibiting maxima in transparency, purity of masstone and tinctov rial strength and range in color from light yellow through oranges to the reds. They can be prepared in all of the desired hues for commercial pigment applications, as warranted.
• a crude cadmium sulfide precipitate is prepared by adding 600 parts of a 9% aqueous solution of sodium sulfide at 60 C. over a period of minutes to 480 parts of an agitated, 34.1 percent aqueous solution of cadmium nitrate maintained at 50 C. Agitation is continued for 1 hour at 50 C. after which time the resulting slurry is filtered and the precipitate is washed to remove soluble salts, dried and pulverized. The dry crude (100 parts) is next combined with 640 parts of a 9 percent aqueous ammonium sulfide solution in a vessel, the vessel is closed and the contents are allowed to age for 16 hours at 30C.
• the product is a highly transparent, golden yellow pigment which exhibits by x-ray diffraction the hexagonal crystal structure of cadmium sulfide.
• the product is a pigment of good coloring power and gives clean, intense tint tones.
• Example 2 The procedure of Example 1 is repeated except that in this example the washed precipitate (400 parts of pulp containing 100 parts of crude on a dry basis) is not dried or pulverized, but is combined with 340 parts of a 17 percent aqueous ammonium sulfide solution in the vessel.
• the crystalline product of this example is a highly transparent, golden yellow pigment and is substantially identical with the product of Example 1.
• Example 3 The procedure of Example l is repeated except that in this example the slurry containing the cadmium sul- -fide precipitate is cooled to 30 C. and transferred directly to the vessel without filtration, washing, drying and pulverizing, and, therein, the slurry is combined with 516 parts of a 24 percent aqueous solution of ammonium sulfide.
• the crystalline product is a transparent golden yellow pigment which is substantially identical with the product of Example 1.
• Example 4 The procedure of Example 1 is repeated except that the vessel contents are aged for 16 hours at 70 C.
• the product of this example is a golden yellow pigment similar in hue, but cleaner by reflected light and less transparent than the product of Example 1.
• Example 5 The procedure of Example 1 is repeated except that the 100 parts of dry crude are combined with a solution prepared by dissolving l 12 parts of ammonium sulfate and 66 parts of sodium sulfide in 462 parts of water.
• the crystalline product of this example is a highly transparent golden yellow pigment which is substantially identical with the product of Example 1.
• EXAMPLE 6 A dry crude cadmium sulfide precipitate is prepared as in Example 1 and the crude (100 parts, dry weight) is pebble milled with 640 parts of an 18 percent aqueous solution of ammonium sulfide for 48 hours at 30 C., after which time the product is recovered as in Example l.
• the crystalline product is a golden yellow pigment which is similar in hue but more opaque than the product of Example 1.
• the product of this example is characterized by unusually high tinctorial strength and cleanness.
• EXAMPLE 7 A crude precipitate of a mixture of cadmium sulfide and zinc sulfide is prepared by adding 487 parts of an aqueous solution containing 148 parts of cadmium nitrate and 18.6 parts of zinc nitrate at 25 C. over 10 minutes to 500 parts of an agitated aqueous solution containing 58 parts of sodium sulfide maintained at 50 C. Agitation is continued for 1 hour at 50 C. after which time the resulting slurry is filtered and the precipitate is recovered in the manner of Example 1.
• the dry crude (100 parts) is next combined with 1,140 parts of a 10.5 percent aqueous ammonium sulfide solution in a vessel, the vessel is closed and the contents are aged without agitation for 16 hours at C., after which time the product is recovered according to the manner of Example 1.
• the product is a highly transparent, primrose yellow pigment having high tinctorial strength and clarity.
• the product exhibits by xray diffraction a hexagonal crystal structure and is a solid solution of cadmium sulfide and zinc sulfide.
• EXAMPLE 8 A crude precipitate of a mixture of cadmium sulfide and mercury sulfide is prepared by adding an aqueous solution previously prepared by combining 575 parts of a 9 percent sodium sulfide solution and 54 parts of a 30 percent mercuric nitrate solution at 60 C. over 10 minutes to 1,810 parts of an agitated 8, percent aqueous solution of cadmium nitrate maintained at 60 C. Agitation is continued for 1 hour at 60 C. after which time the crude precipitate is recovered in the manner of Example l.
• the dry crude parts is next combined with 400 parts of a 55 percent aqueous solution of ammonium sulfide in a vessel, the vessel sealed and the vessel contents aged for 142 hours at 30 C., after which time the aged product is recovered in the manner of Example 1.
• the product is a highly transparent deep orange pigment having high tinctorial strength.
• the product exhibits by x-ray diffraction a hexagonal crystal structure and is a solid solution of cadmium sultide and mercury sulfide.
• a crude precipitate of a mixture of cadmium sulfide and cadmium selenide is prepared by adding a solution of sodium sulfide and sodium selenide (previously prepared by dissolving 14 parts of selenium in 425 parts of a 10.1 percent aqueous solution of sodium sulfide at 60 C.) over 10 minutes to an agitated slurry of cadmium carbonate and cadmium nitrate maintained at 50 C., the slurry having been prepared by reacting 430 parts of a 35 percent aqueous solution of cadmium nitrate with 260 parts of a 3.5 percent aqueous solution of sodium carbonate at 25 C.
• Example 1 Agitation is continued for 1 hour at 50 C., after which time precipitate is removed by filtration. The precipitate is washed to remove soluble salts, dried and pulverized. 100 parts of 5 the pulverized crude precipitate is mixed with 500 parts of a 24 percent aqueous solution of ammonium sulfide in a pressure vessel equipped with an agitator, the vessel is sealed and the contents are agitated for 4 hours at 250 C. under about 1,000 pounds per square inch pressure, after which time the pressure is released and the product recovered in the manner of Example 1.
• the product is a medium red pigment exhibiting by x-ray diffraction a hexagonal crystal structure and is a solid solution of cadmium sulfide and cadmium selenide.
• a process for converting a crude, essentially amorphous precipitate of cadmium sulfide, or a mixture of cadmium sulfide and cadmium selenide, zinc sulfide 0r mercury sulfide into a pigment having an x-ray diffraction pattern characteristic of the hexagonal crystalline structure which process comprises treating said crude,
• essentially amorphous precipitate with sufficient of an aqueous solution containing from about 5 percent to about 55 percent by weight of ammonium sulfide to provide a weight ratio of solution to precipitate of at least 2:1 and a weight ratio of ammonium sulfide to precipitate of 0. 1 :1 to 10:1 at a temperature from about 20 C. to about 275 C. for a period of time ranging from about 1 to about 6 days until said precipitate is converted to the well-ordered hexagonal crystalline state and recovering the crystalline pigment so produced.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)
• Cosmetics (AREA)
• Developing Agents For Electrophotography (AREA)

Priority Applications (9)

Applications Claiming Priority (1)

Publications (1)

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Country Status (9)

Cited By (5)

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Citations (1)

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• 1972
  • 1972-10-24 US US00300028A patent/US3852404A/en not_active Expired - Lifetime
• 1973
  • 1973-10-10 CA CA182,977A patent/CA1004437A/en not_active Expired
  • 1973-10-17 FR FR7337074A patent/FR2203778B1/fr not_active Expired
  • 1973-10-22 DE DE19732352845 patent/DE2352845A1/de not_active Ceased
  • 1973-10-23 GB GB4920273A patent/GB1407915A/en not_active Expired
  • 1973-10-23 CH CH1493873A patent/CH589006A5/xx not_active IP Right Cessation
  • 1973-10-23 IT IT30462/73A patent/IT998884B/it active
  • 1973-10-24 JP JP48119041A patent/JPS4974694A/ja active Pending
  • 1973-10-24 NL NL7314617A patent/NL7314617A/xx not_active Application Discontinuation

Patent Citations (1)

Non-Patent Citations (2)

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