Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/60—Mixing solids with solids
  • B01F23/66—Mixing solids with solids by evaporating or liquefying at least one of the components; using a fluid which is evaporated after mixing
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/14—Heterocyclic carbon compound [i.e., O, S, N, Se, Te, as only ring hetero atom]
  • Y10T436/142222—Hetero-O [e.g., ascorbic acid, etc.]
  • Y10T436/143333—Saccharide [e.g., DNA, etc.]
  • Y10T436/144444—Glucose
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/14—Heterocyclic carbon compound [i.e., O, S, N, Se, Te, as only ring hetero atom]
  • Y10T436/145555—Hetero-N
  • Y10T436/147777—Plural nitrogen in the same ring [e.g., barbituates, creatinine, etc.]
  • Y10T436/148888—Uric acid
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/17—Nitrogen containing
  • Y10T436/171538—Urea or blood urea nitrogen

Definitions

• This application relates to a process for mixing particulate materials and, more particularly, relates to a process for the uniform slurry blending of two or more particulate materials to provide a final homogenous composition.
• the process is particularly suitable for producing a homogenous mixture of chemicals, portions of which may be utilized as reagents in analytical processes.
• Yet a still further object of the present invention is to provide a process for mixing at least two finely divided particulate materials wherein an inert organic liquid is utilized to form a slurry of the materials to be blended, said liquid leaving little or no residue upon subsequent removal thereof after uniformity of blend has been achieved.
• This process has been found satisfactory for uniformly blending rather minute quantities of a first particulate material with a much larger quantity of at least one other particulate material.
• the process has been satisfactory for blending less than 1% of a first material with more than 99% of a second material(s) without denaturing or otherwise adversely affecting the chemical activity of the final formulation.
• the materials being formulated generally can be categorized into the following three broad categories: organic materials, inorganic materials, and biological materials, such as enzymes, albumins, etc.
• this categorization covers a broad range of materials, few of which have similar properties or problems related thereto from a mixing or blending point of view. That is, the categories are so broad that individual members thereof, or groups of members, will have their own related blending problems. Blending a diverse mixture of chemicals further complicates an already complex situation, since it may be difficult to find a common blending technique suitable for all the ingredients.
• some of the materials may be heat sensitive whereas other materials may be carrier or solvent sensitive, such that particular carrier or solvents for blending are automatically excluded, other carriers may be excluded because heat may be necessary to effect removal thereof, etc.
• the provision, therefore, of a process generally applicable to the blending of substantially all particulate materials would be highly desirable.
• the process of the present invention has been found suitable for a wide range of materials falling within each category.
• the particles Prior to slurry formation, the particles are reduced in size to a finely divided state, normally finer than 200 mesh. Where smaller quantities of a particular ingredient are to be uniformly blended throughout a much larger mass, the particles can be reduced even further, normally to a size on the order of 300-400 mesh. Since the materials are normally ground in a very dry environment to prevent either short or long term degradation problems from ambient moisture, the finely divided particles are subject to severe electrostatic charge problems. That is, in the dry environment, the dry particles readily pick up electrostatic charge such that subsequent blending, in a dry mode, is for all intents and purposes impractical.
• slurry formation it is meant the mixing of the finely divided particles with the liquid material in proper quantities such that electrostatic charge problems are eliminated, very little or no excess liquid is utilized, and separation or stratification of the respective particles does not take place.
• the liquid carrier which is added to the finely divided particulate materials to form the slurry desirably has a particular set of unique characteristics. Initially, it is inert so that it will not affect the chemical activity of the final formulation. It should have a high boiling point, i.e. above about room temperature such that it will not be undesirably removed during subsequent blending operations. Optionally, a material with a lower boiling point can be utilized if the blending apparatus is suitably refrigerated during blending.
• the carrier should, on the other hand, have a sufiiciently high vapor pressure at a temperature which does not adversely affect the blended mixture, preferably at a low temperature, so that it can be easily removed, such as by vacuum evaporation.
• the material is free of water, and upon removal, leaves little or no residue which might adversely affect the chemical properties of the formulation.
• One particular material which has been used with great success in the practice of the present invention is the halogenated hydrocarbon 1,1,2 trichloro 1,2,2-trifiuoroethane, also known as Freon TF (a trademark of E. I. du Pont de Nemours & Co., Inc).
• liquid halogenated hydrocarbons include 1,1,2,2 tetrachloro-1,2-difiuoroethane; 1,1,2,2 tetrafiuoro 1,2 dibromoethane; trichloromonofiuromethane; and azeotropes or blends of the aforementioned halogenated hydrocarbon liquids provided the liquid mixture does not affect the chemical activity of the blended formulation and blending condi tions are controlled to prevent denaturation, etc.
• the slurry, after formation, is blended on appropriate equipment, such as a ball mill, a high speed blender, such as a Waring Blendor, etc., for a sufficient period of time to obtain a homogenous mixture.
• a high speed blender such as a Waring Blendor, etc.
• the actual blending time which will be employed varies from composition to composition, batch size, etc., though, on the average, the blending time is on the order of about one to about six hours.
• high speed e.g., greater than 10,000l2,000 r.p.m.
• blending times can be reduced to as little as three minutes or so. Because in many instances heat sensitive materials are being blended, it is desirable in such circumstances to maintain the temperature of the composition as close to room temperature as possible. This will avoid deleterious denaturing of heat sensitive materials such that the activity of the final formulation can be more appropriately regulated.
• the liquid carrier is removed, normally by vacuum evaporation. If non-heat sensitive, materials are being blended, the liquid can be boiled off, though for most materials to be utilized in a reagent mode vacuum evaporation assures against loss of chemical activity. Vacuum evaporation is most easily achieved by taking the jar containing the now uniformly blended material and placing it with the top removed, in a vacuum cabinet. After removal of the carrier, the uniformly mixed material is separated from the grinding media used in the blending process. The uniform mixture can be utilized as the powdered material thus obtained or tableted, as desired.
• Example I This example describes the blending and preparation of a reagent formulation suitable for use, along with the formulation of Example II, in the determination of glucose in body fiuids.
• the formulation contains the following ingredients in substantially the proportions as given:
• Sufiicient chemicals for a 20,000 tablet batch are weighed out in a dry room and placed in a dark brown, ball milling bottle, or other suitable porcelain ball milling jar.
• the bottle should be large enough to be filled to about 60% of its total capacity with the dry powder added thereto.
• Sufficient grinding media in the form of Coors HD balls, are added in an amount equal to about 40% of the remaining volume of the bottle. The size and quantity of the grinding media can be varied as desired.
• Sufiicient Freon TF carrier is added to make a thick slurry; in this particular example, about 400 milliliters of liquid is added.
• a sufiiciently thick unplasticized polyethylene sheet is placed between the bottle and the cap placed thereon to prevent contamination of metallic particles from the metallic cap.
• the slurry is blended on a ball mill for about 4 hours at approximately r.p.m.
• the cap is removed and replaced with a lint-free porous cover secured by a rubber band and the bottle is placed at a 30-degree angle in a vacuum chamber equipped with a Dry Ice-acetone trap. Vacuum is slowly applied, at room temperature, to prevent flash boiling of the Freon TF carrier. The vacuum evaporation is continued for a sufficient period of time, normally about two hours, to remove excess carrier.
• the blended powder is then passed through a 10 mesh screen to remove the grinding media.
• a 10 mesh screen to remove the grinding media.
• Example II The procedure of Example I is repeated to uniformly blend the following chromogen formulation suitable for use, along with the formulation of Example I, in the determination of glucose in body fluids:
• Example III The procedure of Example I is repeated to uniformly blend the following chromogen formulation suitable for use, along with the formulation of Example IV, in a total protein analysis by the biuret method:
• Example IV The procedure of Example I is repeated to uniformly blend the following alkalyzing formulation which is suitable for use, along with the formulation of Example III,
• Example V The procedure of Example I is repeated to uniformly blend the following formulation which is suitable for use, along with the formulations given in Examples VI and VIII, in the determination of uric acid in body fluids:
• Example VI The procedure of Example I is repeated to uniformly blend the following alkalyzing formulation suitable for use, along the formulations given in Examples V and VII, in the determination of uric acid in body fluids:
• Example VII The procedure of Example I is repeated to uniformly blend the following chromogen formulation suitable for use, along with the formulations given in Examples V and VI, in the determination of uric acid in body fluids:
• Example VIII The procedure of Example I is repeated to uniformly blend the following enzyme formulation suitable for use, along with the formulations of Examples IX and X, in the determination of blood urea nitrogen:
• Example IX The procedure of Example I is repeated to uniformly blend the following formulation suitable for use, along with the formulations of Examples VIII and X, in the determination of blood urea nitrogen:
• Example X The procedure of Example I is repeated to uniformly blend the following formulation suitable for use, along with the formulations of Examples VIII and IX, in the determination of blood urea nitrogen:
• sufiicient chemicals for a 1000 tablet batch are mixed with 35 milliliters of Freon TF to form the slurry which is then blended on the ball mill for one and one-half hours.
• Example XI The procedure of Example I is repeated to uniformly blend the following formulation suitable for use in a total protein determination by the biuret method:
• Example II minute quantitles of ortho-dianisidine-dihydrochloride have been uniformly blended with major quantities of mannitol in the approximate ratio of one part of ortho-dianisidine to about 420 parts mannitol.
• Example V minute quantities of copper sulfate have been uniformly blended with a major quantity of potassium chloride in the approximate ratio of about one part copper sulfate per 180 parts potassium chloride.
• any process which is capable of uniformly and repeatedly blending a plurality of particulate materials to the desired uniformity of blend is of great use and benefits, directly or indirectly, all concerned.
• the process of the present invention has been found to achieve such results, as indicated above, even though the ratio of ingredients in different formulations varies widely.
• a process for blending a plurality of particulate materials which comprises reducing a minute quantity of a first particulate material to a finely-divided state, reducing a major quantity of a second particulate material to a finely divided state, admixing said finely divided first and second particulate materials with only a sufficient amount of an inert organic carrier to form a thick slurry, blending said slurried mixture for a period of time sufiicient to uniformly disperse said first particulate material throughout said major quantity of said second particulate material and, thereafter, returning said particles to a dry unagglomerated condition by removing said carrier material Without adversely affecting the chemical activity of said blended materials or disturbing the uniformity of blend.
• a process for blending a plurality of particulate materials comprising forming a slurry by mixing finelydivided, dry particles of a plurality of different materials with an inert non-aqueous carrier, blending said slurried mixture for a period of time sufficient to achieve a homogeneous distribution of said finely-divided particles throughout said slurry, and returning said particles to a dry, unagglomerated condition by removing said inert, non-aqueous carrier without affecting the chemical activity of said mixture or disturbing the uniformity of blend.
• said inert carrier is an organic material having a boiling point at least as high as room temperature and having a sufiicient vapor pressure at low temperatures to permit removal by vacuum evaporation.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Investigating Or Analyzing Non-Biological Materials By The Use Of Chemical Means (AREA)
• Sampling And Sample Adjustment (AREA)
• Solid-Sorbent Or Filter-Aiding Compositions (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=25179461

Family Applications (1)

Country Status (4)

Cited By (2)

• 1969
  • 1969-02-10 US US800822A patent/US3647713A/en not_active Expired - Lifetime
• 1970
  • 1970-02-06 GB GB577670A patent/GB1302409A/en not_active Expired
  • 1970-02-10 FR FR7004722A patent/FR2032850A5/fr not_active Expired
  • 1970-02-10 DE DE19702005964 patent/DE2005964A1/de active Pending

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