Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/02—Cosmetics or similar toiletry preparations characterised by special physical form
  • A61K8/0241—Containing particulates characterized by their shape and/or structure
  • A61K8/0275—Containing agglomerated particulates
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/19—Cosmetics or similar toiletry preparations characterised by the composition containing inorganic ingredients
  • A61K8/25—Silicon; Compounds thereof
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K8/00—Cosmetics or similar toiletry preparations
  • A61K8/18—Cosmetics or similar toiletry preparations characterised by the composition
  • A61K8/72—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds
  • A61K8/81—Cosmetics or similar toiletry preparations characterised by the composition containing organic macromolecular compounds obtained by reactions involving only carbon-to-carbon unsaturated bonds
  • A61K8/8105—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • A61K8/8111—Homopolymers or copolymers of aliphatic olefines, e.g. polyethylene, polyisobutene; Compositions of derivatives of such polymers
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q11/00—Preparations for care of the teeth, of the oral cavity or of dentures; Dentifrices, e.g. toothpastes; Mouth rinses
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
  • A61Q19/00—Preparations for care of the skin
  • A61Q19/10—Washing or bathing preparations
• • 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
  • C09C1/0081—Composite particulate pigments or fillers, i.e. containing at least two solid phases, except those consisting of coated particles of one compound
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/02—Floating bodies of detergents or of soaps
• • C—CHEMISTRY; METALLURGY
  • C11—ANIMAL OR VEGETABLE OILS, FATS, FATTY SUBSTANCES OR WAXES; FATTY ACIDS THEREFROM; DETERGENTS; CANDLES
  • C11D—DETERGENT COMPOSITIONS; USE OF SINGLE SUBSTANCES AS DETERGENTS; SOAP OR SOAP-MAKING; RESIN SOAPS; RECOVERY OF GLYCEROL
  • C11D17/00—Detergent materials or soaps characterised by their shape or physical properties
  • C11D17/06—Powder; Flakes; Free-flowing mixtures; Sheets
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61K—PREPARATIONS FOR MEDICAL, DENTAL OR TOILETRY PURPOSES
  • A61K2800/00—Properties of cosmetic compositions or active ingredients thereof or formulation aids used therein and process related aspects
  • A61K2800/40—Chemical, physico-chemical or functional or structural properties of particular ingredients
  • A61K2800/59—Mixtures
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2002/00—Crystal-structural characteristics
  • C01P2002/02—Amorphous compounds
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/50—Agglomerated particles
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/51—Particles with a specific particle size distribution
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2004/00—Particle morphology
  • C01P2004/60—Particles characterised by their size
  • C01P2004/61—Micrometer sized, i.e. from 1-100 micrometer
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/10—Solid density
• • C—CHEMISTRY; METALLURGY
  • C01—INORGANIC CHEMISTRY
  • C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
  • C01P2006/00—Physical properties of inorganic compounds
  • C01P2006/19—Oil-absorption capacity, e.g. DBP values

Definitions

• This invention relates to particle agglomerates and is particularly but not necessarily exclusively concerned with particle agglomerates intended for suspension in liquid-based media, especially media in which the liquid base is of relatively low viscosity.
• the particle agglomerates are employed in liquid-based personal care and hygiene formulations and cosmetic formulations in order to impart a desired characteristic, such as a sensory attribute (e.g. tactile), to the product.
• a desired characteristic such as a sensory attribute (e.g. tactile)
• Examples of the use of particle agglomerates in such formulations are disclosed in published International Patent Applications Nos. WO-A-94/12151 ,
• WO-A-96/09033, WO-A-96/09034 and WO-A-97/30126 are composed of inorganic particles such as for example amorphous silica or silicas. Wide variations in particle density cause suspension problems when formulating into typical exfoliating compositions in that the dense particles tend to sediment and the low density particles tend to float which impairs the visual or functional performance.
• adding a suspending agent or increasing the viscosity by adding rheology modifiers to the formulation has been the only way to prevent settlement - thus the entire formulation had to be modified in order to modulate the suspension of a component which might only be present at 1 % or less.
• the base liquid is often of low viscosity for aesthetic, functional or cost reasons. Aggregates of dense materials such as silicas will tend to settle in such formulations with consequent impairment of the visual appearance, sensory qualities and/or functional performance of the formulation. For this reason, especially where the formulation has a relatively low viscosity liquid base, suspending or thickening agents have to be incorporated in the formulation in order to maintain the agglomerates in suspension. Examples of the types of suspending or thickening agents used for this purpose are given in for instance International Patent Application No. WO 94/12151 and EP-A-0571 193. The addition of suspending or thickening agents results in changes in the rheology of the formulation which, in turn, can have a radical affect on the sensory or other desirable qualities of the formulation.
• the lower density particles have a density in the range from 0.01 to 0.4 g/ml, more preferably 0.015 to 0.25 g/ml and typically 0.02 to 0.15 g/ml.
• the lower density particles are conveniently in the form of low density, gas-encapsulating particles; however, we do not exclude the possibility of other low density particles being employed, e.g. polyethylene particles such as those solid available from Allied Signal Inc, New Jersey, USA under the trade name A-C Polyethylene.
• the combination, by agglomeration, of the high density inorganic particles and said low density particles allows the density of the granules to be tailored according to requirements.
• the material as defined in the above aspects of the invention is particularly suitable for incorporation in liquid-based media, especially media having low viscosity liquid bases, since the low density particles impart buoyancy to the granules thereby largely eliminating the need for inclusion of suspending or thickening agents for the purpose of counteracting sedimentation of the high density particle agglomerates.
• the high density particles will be the primary particle in terms of imparting a particular attribute, e.g.
• the low density particle may be primary particle in this sense and that the co-agglomeration with high density particles is effected in order to adjust the effective density of such primary particles to counteract, largely without the aid of suspending or thickening agents, any tendency for the low density particles to float with consequent impairment of the visual appearance or functional performance of the liquid-based composition.
• the previously mentioned polyethylene particles such as those solid available from Allied Signal Inc, New Jersey, USA under the trade name A-C Polyethylene, are suitable for use as a low density particle having a sensory attribute.
• a material in the form of granules of high density inorganic particles co-agglomerated with low density, gas-encapsulating particles are suitable for use as a low density particle having a sensory attribute.
• liquid-based medium containing material according to the above aspects of the invention, the granules being dispersed throughout said medium.
• Liquid-based medium as used herein is not limited to formulations which are of a pourable nature; also included are other liquid-based formulations such as lotions, creams and gels.
• the invention is particularly expedient in the case of liquid-based media employing low viscosity liquids, particularly liquids having viscosities in the range of 1 ,000 to 10,000 mPas "1 but is also expedient for lotions, creams and gels having viscosities in the range of 1 ,000 to 100,000 mPas "1 , preferably 2,000 to 40,000 mPas 1 and more preferably 2,000 to 20,000 mPas -1 .
• the amount of low density particles employed in the granules will depend on the extent to which the density of the granules needs to be tailored for a particular application .
• the low density particles will constitute up to 20% by weight of the granular composition, for instance from 1 to 12% by weight, with 1 to 8% by weight being preferred, more preferably 1 to 5% by weight.
• the liquid-based medium may take various forms such as a personal care formulation (e.g. skin cleansing/exfoliating agent, mouthwash, liquid toothpastes, shower gel or hair care agent such as shampoo), a personal hygiene formulation or a cosmetic formulation.
• a personal care formulation e.g. skin cleansing/exfoliating agent, mouthwash, liquid toothpastes, shower gel or hair care agent such as shampoo
• the liquid-based medium for such applications will typically contain the granular material according to the invention in an amount up to of 20% by weight, e.g. 1 to 20% by weight, more usually from 1 to 8% by weight.
• the medium may be aqueous or non-aqueous and may also include other components conventionally employed in personal care, personal hygiene and cosmetic products.
• water may be present in a total amount of from 10 to 90% by weight, preferably from 20 to 80% by weight and most preferably from 40 to 75% by weight.
• surfactants may be present, e.g. selected from anionic, nonionic, amphoteric and zwitterionic surfactants or mixtures thereof, typically in an amount in excess of 0.1 % by weight, e.g. 1 to 80% by weight and more preferably from 2 to 50% by weight. Any surfactants may be used. Also, for products such as liquid toothpastes, one or more humectants may be present in the range of 1 to 70% by weight, preferably 5 to 70% by weight.
• Suitable additional ingredients may include components selected from: electrolytes, for instance water soluble alkali metal or ammonium salts (e.g. sodium chloride); pearlescing agents; perfumes; flavours; vitamins; opacifiers; colourings; dentrifice agents such as anti-plaque agents and agents for combating tooth-sensitivity; preservatives; anti-dandruff agents; hair conditioning agents; skin moisturising agents; herb and plant extracts; essential oils; emollients; proteins; pH adjusting agents; or anti-microbials.
• electrolytes for instance water soluble alkali metal or ammonium salts (e.g. sodium chloride); pearlescing agents; perfumes; flavours; vitamins; opacifiers; colourings; dentrifice agents such as anti-plaque agents and agents for combating tooth-sensitivity; preservatives; anti-dandruff agents; hair conditioning agents; skin moisturising agents; herb and plant extracts; essential oils; emollients; proteins; pH adjusting
• liquid-based medium in accordance with the invention, sedimentation can be overcome without the aid of suspending agents (e.g. Carbomers) or rheology modifiers (e.g. synthetic hectorite (laponite) clay) or organic builders such as sodium carboxymethyl cellulose, xanthan gum and carrageen.
• suspending agents e.g. Carbomers
• rheology modifiers e.g. synthetic hectorite (laponite) clay
• organic builders such as sodium carboxymethyl cellulose, xanthan gum and carrageen.
• the liquid-based media is substantially free of components (such as suspending agents and/or rheology modifiers) which are conventionally incorporated primarily or solely for their ability to counteract sedimentation of particulate solids within the medium.
• inorganic particles e.g. calcite or agglomerated inorganic particles as disclosed in WO-A-97/30126
• the co-agglomerate granules have a density which, when measured by Vertical Scan Macroscopic analysis, is less (or no more than 4% greater) than that of the liquid base - for example up to 10% less than the density of the liquid base.
• the inorganic content may comprise one or more inorganic particulate materials; where more than one inorganic particulate material is employed they may be chemically and/or physically different.
• the inorganic particles may be composed of material selected from the group comprising silicas, especially amorphous silicas, aluminas, calcium carbonates, dicalcium phosphate, tribasic calcium phosphates, hectorites, saponites, aragonites, dolomites, talcites, hydroxytalcites, spangolites, zincites, zincosilicates, insoluble metaphosphates, calcium pyrophosphates, hydroxyapatites, perlites, zeolites, clays, magnesium carbonate, pumice and volcanic ash, or mixtures of two or more of these components.
• silicas especially amorphous silicas, aluminas, calcium carbonates, dicalcium phosphate, tribasic calcium phosphates, hectorites, saponites, aragonites, dolomites, talcites, hydroxytalcites, spangolites, zincites, zincosilicates, insoluble metaphosphates, calcium pyrophosphates, hydroxyapati
• mixtures of two or more inorganic particulate materials are silicas plus carbonates, silicas plus dicalcium phosphate, silicas plus perlite, abrasive silicas plus thickening silicas, hydroxyapatites plus silicas or metaphosphates, calcium carbonates plus dicalcium phosphates etc. Particularly preferred are mixtures of lower and higher structure silicas.
• the granules may, in addition to the co-agglomerated higher and lower density particles, incorporate other components such that the granules act (for instance by virtue of their porosity and/or friability) as vehicles for carrying and, during use of the medium, releasing or delivering benefit ingredients.
• the benefit ingredients employed may include substances such as colouring dyes or pigments, cosmetic benefit agents (e.g. silicone oils) or pharmaceutical actives such as salicyclic acid or anti-dandruff actives (e.g. zinc pyrithione) in the case of hair treatment products.
• suitable coloured pigments for example pigment dispersions under the Cosmenyl tradename or pigment powders under the Hostaperm trade name or Cosmetic Pink RC 01 ( D & C red No. 30 ) supplied by Ciariant (formerly Hoechst) or Ultramarine Grade 54 supplied by Holliday Pigments, can be added to the composition without affecting the strength of the granule.
• the granules may incorporate opacifiers such as titanium dioxide and/or material having a therapeutic affect on the gums or teeth or oral cavity, e.g. an anti-plaque agent such as zinc citrate or stannous pyrophospate, anti-microbial agents such as Triclosan, anti-caries agents such as sodium fluoride and sodium monofluorophosphate, anti-tartar agents such as sodium pyrophosphate and potassium pyrophosphate, and agents such as potassium salts or strontium salts for countering tooth sensitivity.
• opacifiers such as titanium dioxide and/or material having a therapeutic affect on the gums or teeth or oral cavity
• an anti-plaque agent such as zinc citrate or stannous pyrophospate
• anti-microbial agents such as Triclosan
• anti-caries agents such as sodium fluoride and sodium monofluorophosphate
• anti-tartar agents such as sodium pyrophosphate and potassium pyrophosphate
• agents such as potassium salts
• the granules may be so constituted as to be friable under conditions of use of liquid-based media incorporating the granules so that the additional component or components incorporated in the granules may be released in use, for example as disclosed in WO-A-94/12151 , WO-A-96/09033 and WO-A-96/09034, the disclosures of which are incorporated herein by this reference.
• the granular strength of the granules may be in accordance with the teaching of WO-A-97/30126, the entire disclosure of which is incorporated herein by this reference.
• granules are in the form of a granular composition comprising 45 to 99% by weight of a water insoluble particulate of which 5 to 90% is made from a first particulate component which is composed of material selected from said group and has a weight mean particle size of less than 20 micron and an oil absorption capacity from 60 to 180g/100g, and of which
• 5 to 90% is made from a second particulate component which is composed of material selected from the group consisting of amorphous silicas, low density aluminas and expanded perlites and has a weight mean particle size of less than 20 micron and an oil absorption capacity from 150 to 350g/100g, the granular composition preferably having a particle size, as measured by sieve analysis, of 95% below 1500 micron (more preferably below 1000 micron and most preferably below 800 micron) and 95% above 40 micron (more preferably above 45 micron).
• the particle size of the granule can be over a broad range. For example, in dental applications 40 to 600 microns is optimum and for skin treatment formulations particles within the range of 40 to 1000 microns are preferred.
• the granules may be produced by any agglomeration or compaction technique. Agglomeration for instance can be achieved by pan granulation, dry roller compaction, extrusion, spray granulation or spinning disc granulation.
• the liquid-based medium is preferably in the form of a cosmetic, personal care or personal hygiene formulation in which the granules impart a sensory benefit which is perceivable in use of the formulation for instance by virtue of their size, shape and strength.
• the gas-encapsulating particles typically have a weight average diameter in the range of 1 to 150 micron, more preferably 10 to 100 micron and even more preferably 10 to 30 micron.
• the gas-encapsulating particles are of the type comprising a polymeric shell enclosing a gas, preferably expanded thermoplastic gas-encapsulating particles of the type described for example in EP -A-56219, EP-A-1 12807, EP-A-320473, EP-A-348372, EP-A-486080 and US-A-3615972, the disclosures of which are incorporated herein by this reference.
• a gas preferably expanded thermoplastic gas-encapsulating particles of the type described for example in EP -A-56219, EP-A-1 12807, EP-A-320473, EP-A-348372, EP-A-486080 and US-A-3615972, the disclosures of which are incorporated herein by this reference.
• Such particles are typically produced by suspension polymerisation where a liquid monomer or monomer mixture containing condensed propellant is dispersed in an aqueous medium containing suspending agent and polymerisation catalyst. The resulting microbeads or spheres consist
• the beads expand by heating to a temperature above the boiling point of the propellant and the softening point of the polymer.
• the thermoplastic shell of the beads may consist of polymers or copolymers of e.g. vinyl chloride, vinylidene chloride, acryionitrile, methyl methacrylate or styrene or mixtures thereof.
• the particle size of the unexpanded beads and, hence, of the expanded ones may vary within wide limits; the unexpanded beads may, for example, be 1 micron to 1 mm, preferably 2 micron to 0.5 mm and particularly 5 micron to 50 micron.
• the propellant suitably makes up 5-30% by weighf of the microbead.
• microbead product is Expancel (Registered Trade Mark) which has a thermoplastic shell of a vinylidene chloride/acrylonitrile copolymer and contains iso-butane as propellant.
• Expancel Registered Trade Mark
• the amount of microbead of the Expancel type employed in the production of the granular material of the invention ranges from 1 to 10%, e.g. from 2 to 8%, by weight of the granular composition.
• a material in the form of granules of high density inorganic particles co-agglomerated with expandable particles comprising a volatile medium encapsulated within a shell of polymeric material.
• expansion of the expandable particles may be implemented (for instance by the application of heat) prior to, subsequent to or at the time of incorporation of the granules in a liquid-based medium, with consequent reduction in density of the granules.
• a liquid-based medium in which are dispersed inorganic particle agglomerates having a density which, when measured by Vertical Scan Macroscopic analysis, is no more than 4% greater than that of the base liquid.
• the invention further encompasses a process for the production of a granular material of controlled density, which process comprises combining particles of one or more high density inorganic materials with density-reducing particles to form co-agglomerates of the high density particles with the density-reducing particles, the density-reducing particles being constituted by particles having a density less than that of water or by precursors of such particles.
• precursors we mean that particles which in the precursor state may or may not have a density less than that of water but are susceptible to treatment resulting in a reduction in their density to below that of water.
• Such precursor particles may for instance be of the type described in EP -A-56219, EP-A-1 12807, EP-A-320473, EP-A-348372, EP-A-486080 and US-A-3615972 when in their unexpanded form, expansion and density reduction being effected by the application of heat.
• a process of producing a liquid-based formulation in which particles are suspended substantially without the aid of suspending agents and/or rheology modifiers comprising combining particles of one or more high density inorganic materials with density-reducing particles to form co-agglomerates of the high density particles with the density-reducing particles to allow or cause modification of the density of the granular material consistent with securing suspension of the granules in the formulation in the absence of any suspending agent or rheology modifier, and dispersing the granular material in said formulation.
• Expancel particles Density The density of Expancel particles is measured with an Accupyc 1330 Pycnometer according to Analytical Method MS 29b as referenced in the Expancel (RTM) Product Specification (Issue 95.04) for Expanded Microspheres, issued by Nobel Industries, Sweden and supplied in the UK by Boud Marketing Limited of Laddingford, Kent, England.
• Particle size of Expancel particles is measured according to the method described in Technical Bulletin No.3 "Particle size of Expancel Microspheres" as referenced in the Expancel (RTM) Product Specification (Issue 95.04), issued by Nobel Industries, Sweden and supplied in the U.K. by Boud Marketing, Laddingford, Kent. The manufacturer/supplier defines particle size for Expancel microspheres as the weight average diameter, which is the same as the weight mean particle size.
• Oil absorption is determined by the ASTM spatula rub-out method (American Society of Test Material Standards D, 281 ). The test is based on the principle of mixing linseed oil with a given weight of the particulate matter, e.g. silica, by rubbing with a spatula until a stiff putty-like paste is formed which will not break or separate when it is cut with a spatula. The oil absorption is then calculated from the volume of oil (V cm 3 ) used to achieve this condition and the weight W in grams of particulate matter by means of the equation:
• Oil absorption (V x 100)/W, i.e. expressed in terms of cm 3 oil/100 g particulate matter.
• Particle Size The particle size of the particulate material before agglomeration is determined using a Malvern Mastersizer model X, made by Malvern Instruments of
• Malvern, Worcestershire, England, with MS15 sample presentation unit This instrument uses the principle of Fraunhofer diffraction, utilising a low power He/Ne laser.
• the particulate material is dispersed uitrasonically in water for 7 minutes to form an aqueous suspension, the suspension then being mechanically stirred before carrying out the measurement procedure outlined in the instruction manual for the instrument, using a 45 mm lens in the detector system.
• the Malvern Particle Sizer measures the weight mean particle size of the particulate material.
• the weight mean particle size (d 50 ) or 50 percentile; the 10 percentile d 10 and 90 percentile d 90 are readily obtained from the data generated by the instrument.
• DCBD Dry Compacted Bulk Density
• Particle Density (Vertical Scan Macroscopic Analyser): The density of the particle aggregates is determined using a Turbiscan MA 1000 automated, near infrared, vertical scan macroscopic analyser manufactured by Formulaction, Ramonville, France and supplied in the U.K. by Fullbrook Systems, Hertfordshire.
• the Turbiscan MA1000 carries out step-by-step vertical scanning of the sample and converts the macroscopic aspect of the mixture into graphics. It works in kinetic mode and shows the physical evolution of the sample by simple comparison of graphs.
• the Turbiscan MA1000 is able to detect accurately and reproducibly particle migration (creaming, sedimentation) and particle aggregation (coalescence, flocculation) at a very early stage in opaque and concentrated colloidal dispersions.
• the core system in the Turbiscan MA 100 is its reading head which moves vertically along a flat bottomed cylindrical cell.
• the detection head contains a pulsed near-infrared light source and two synchronous detectors.
• the transmission detector picks up the light through the sample; the light scattering detector receives the light scattered back from the sample.
• the reading head scans the entire length of the sample, acquiring transmission and light scattering data every 40um.
• the signal is first treated by the Turbiscan MA1000 current to voltage convertor.
• the integrated microprocessor's software handles data acquisistion, analog to digital conversion, data storage, motor control and computer dialogue. Two kinds of light scattering/transmission graph modifications are detected by the Turbiscan MA1000:
• the particle aggregate samples for particle migration velocity measurement and hence particle density determination were prepared by stirring the particle aggregates with a spatula into a simple liquid base surfactant formulation in which no suspending agent or rheology modifier was included, as detailed in Example 5 of the invention, followed by:
• the density of the liquid base samples is determined using an Anton Paar Calculating Density meter (DMA.46 ), obtainable from Paar Scientific Ltd, London, England.
• the instrument is based on the principle of the change of the natural frequency of a hollow oscillator when filled with a different liquid or gas. The mass and thus the density of the liquid changes this natural frequency due to a gross mass change.
• the instrument is calibrated at 20 °C. The calibration procedure is detailed in the operating manual for the instrument.
• the sample is injected into the lower hole of the U tube using a plastic tipped syringe until there are no air bubbles.
• the density of the sample is recorded when the instrument records six consecutive readings that are the same.
• silica blend was agglomerated at 200 g batch size, laboratory scale with deionised water (in a wate ⁇ solids ratio of 1 .1 :1 ) using a Sirman SV6 mixer, supplied by Metcalfe Catering Equipment Limited of Blaenau Ffestiniog, Wales.
• the resulting wet agglomerate was then dried in an oven at 1 50°C for 4 hours, gently forced through a 500 micron sieve screen and sieved at 106 micron to adjust the particle size distribution.
• agglomerate compositions were prepared according to the method of Example 1 with the exception that the silicas were initially blended together with an amount of an expanded polymeric gas-containing beads or microspheres, Expancel 461 DE20 (available from Nobel Industries, Sweden through Boud Marketing Limited of Laddingford, Kent, England) to obtain the compositions given in the Table 2 below.
• Expancel 461 DE20 available from Nobel Industries, Sweden through Boud Marketing Limited of Laddingford, Kent, England
• the density of the granules produced by agglomeration was measured in a simple base surfactant system in which no suspending agent or rheology modifier was included, density being measured by means of a Vertical Scan
• Macroscopic analyser (Turbiscan MA1000, obtainable from Formulaction, Ramonville, France).
• the base solution had the following composition:
• Cocamidopropyl betaine 2 (30%) 15.00 Sodium chloride 2.50 Sample (Ex 1 to 5) 1 .00 Preservatives qs Deionised water balance to 100% Manro ALS30 ( ex Hickson-Manro Ltd )
• the density of the base solution is 1 .038g/ml, measured using a density meter.
• the average particle size of the aggregates is 300 microns and the base viscosity is -JOOcps, which is required for calculation of agregate density using Stokes Einstein law.
• the following base liquid surfactant system was prepared in which inorganic materials according to Examples 1 to 5 were used. No thickeners and/or suspending agents were included in this base formulation.
• Component %wt Component %wt
• the density of the liquid base in this case is 1 .0193, measured using a density meter.
• Example 3 aggregates matches that of the liquid base employed in Example 6 as the Example 3 aggregates were stably suspended without the need for auxiliary suspending agents or rheology modifiers.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Organic Chemistry (AREA)
• Birds (AREA)
• Epidemiology (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Wood Science & Technology (AREA)
• Dermatology (AREA)
• Composite Materials (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Inorganic Chemistry (AREA)
• Cosmetics (AREA)
• Pigments, Carbon Blacks, Or Wood Stains (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=10823472

Family Applications (1)

Country Status (11)

Families Citing this family (17)

Family Cites Families (5)

• 1997
  • 1997-12-12 GB GBGB9726227.3A patent/GB9726227D0/en not_active Ceased
• 1998
  • 1998-12-08 WO PCT/GB1998/003659 patent/WO1999031184A1/en not_active Application Discontinuation
  • 1998-12-08 PL PL98341049A patent/PL341049A1/xx unknown
  • 1998-12-08 CA CA002311758A patent/CA2311758A1/en not_active Abandoned
  • 1998-12-08 BR BR9813500-7A patent/BR9813500A/pt not_active Application Discontinuation
  • 1998-12-08 CN CN98812185A patent/CN1282355A/zh active Pending
  • 1998-12-08 AU AU14428/99A patent/AU1442899A/en not_active Abandoned
  • 1998-12-08 ID IDW20001072A patent/ID26820A/id unknown
  • 1998-12-08 EP EP98958359A patent/EP1037949A1/en not_active Withdrawn
  • 1998-12-08 KR KR1020007006366A patent/KR20010033013A/ko not_active Application Discontinuation
  • 1998-12-08 JP JP2000539095A patent/JP2002508430A/ja active Pending

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events