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WO1994021733A1 - Pigments presentant de bonnes proprietes de dispersion de la lumiere - Google Patents

Pigments presentant de bonnes proprietes de dispersion de la lumiere Download PDF

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Publication number
WO1994021733A1
WO1994021733A1 PCT/SE1994/000202 SE9400202W WO9421733A1 WO 1994021733 A1 WO1994021733 A1 WO 1994021733A1 SE 9400202 W SE9400202 W SE 9400202W WO 9421733 A1 WO9421733 A1 WO 9421733A1
Authority
WO
WIPO (PCT)
Prior art keywords
silicic acid
titanium dioxide
titanium
particles
covered
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/SE1994/000202
Other languages
English (en)
Inventor
Jan-Erik Otterstedt
Orvar Erik Otterstedt
Per Johan Sterte
Peter Greenwood
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
KOMPOPIGMENT Ltd
Original Assignee
KOMPOPIGMENT Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by KOMPOPIGMENT Ltd filed Critical KOMPOPIGMENT Ltd
Priority to AU62938/94A priority Critical patent/AU6293894A/en
Publication of WO1994021733A1 publication Critical patent/WO1994021733A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • BPERFORMING OPERATIONS; TRANSPORTING
    • B82NANOTECHNOLOGY
    • B82YSPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00Nanotechnology for materials or surface science, e.g. nanocomposites
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09BORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B67/00Influencing the physical, e.g. the dyeing or printing properties of dyestuffs without chemical reactions, e.g. by treating with solvents grinding or grinding assistants, coating of pigments or dyes; Process features in the making of dyestuff preparations; Dyestuff preparations of a special physical nature, e.g. tablets, films
    • C09B67/006Preparation of organic pigments
    • C09B67/0061Preparation of organic pigments by grinding a dyed resin
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT 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
    • C09C1/00Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/28Compounds of silicon
    • C09C1/30Silicic acid
    • C09C1/3045Treatment with inorganic compounds
    • C09C1/3054Coating
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT 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
    • C09C1/00Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/28Compounds of silicon
    • C09C1/30Silicic acid
    • C09C1/3063Treatment with low-molecular organic compounds
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT 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
    • C09C1/00Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
    • C09C1/40Compounds of aluminium
    • C09C1/42Clays
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT 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
    • C09C3/00Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
    • C09C3/06Treatment with inorganic compounds
    • C09C3/063Coating
    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09CTREATMENT 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
    • C09C3/00Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
    • C09C3/08Treatment with low-molecular-weight non-polymer organic compounds
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2002/00Crystal-structural characteristics
    • C01P2002/02Amorphous compounds
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/30Particle morphology extending in three dimensions
    • C01P2004/32Spheres
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/51Particles with a specific particle size distribution
    • C01P2004/52Particles with a specific particle size distribution highly monodisperse size distribution
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/60Particles characterised by their size
    • C01P2004/61Micrometer sized, i.e. from 1-100 micrometer
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/60Particles characterised by their size
    • C01P2004/62Submicrometer sized, i.e. from 0.1-1 micrometer
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/60Particles characterised by their size
    • C01P2004/64Nanometer sized, i.e. from 1-100 nanometer
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2004/00Particle morphology
    • C01P2004/80Particles consisting of a mixture of two or more inorganic phases
    • C01P2004/82Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases
    • C01P2004/84Particles consisting of a mixture of two or more inorganic phases two phases having the same anion, e.g. both oxidic phases one phase coated with the other
    • C01P2004/86Thin layer coatings, i.e. the coating thickness being less than 0.1 time the particle radius
    • CCHEMISTRY; METALLURGY
    • C01INORGANIC CHEMISTRY
    • C01PINDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
    • C01P2006/00Physical properties of inorganic compounds
    • C01P2006/80Compositional purity

Definitions

  • the present invention relates to a pigment having high light scattering ability and relates more specially to such a pigment comprising titanium dioxide and a method for the production of such pigments.
  • Titanium dioxide is virtually the dominating white pigment in different applications. Its supreme opacity and covering ability compared to other kinds of white pigments, when it is used in coverings, depend on the high refraction index of the titanium dioxide.
  • titanium dioxide pigments as for other pigments the rule exists that full colour strength of the pigment, when it is dispersed, is obtained only with particles being less than 100 nm. If, however, a higher scattering ability of the pigment is desired, the particle size must be appreciably higher and in the range of 300 nm.
  • the properties of the titanium dioxide are such that the pigment has a broad size distribution of the particles with an amount of material which is larger than 300 nm but also a large amount of material below 300 nm.
  • the titanium dioxide also flocculates very easily when it is present in the shape of small particles and when it is used together with water soluble polymers.
  • titanium dioxide particles Due to the different properties of the titanium dioxide particles the problem exists that it is very difficult to disperse titanium dioxide to a predestinated desired particle size which is thereafter maintained during a succeeding treatment and admixing into a carrier substance.
  • Typical titanium dioxide particles have, as mentioned above, a very large size distribution and they agglomerate very easily which results in that particles of a certain size will not be brought about in a simple way.
  • pigment particles of small size give high colour strength whereas particles of greater size give higher light scattering it is of course difficult or impossible to attain a pigment having the right particle composition by typical titanium dioxide particles so that a high colour strength or a large scattering ability can be chosen. This means that more titanium dioxide pigment than what is absolutely necessary to obtain the desired colour strength and/or colour distribution must be used.
  • a pigment has therefore been attained having a large light scattering ability which is characterized in that it comprises a core which does not consist of mica and which is substantially round and has a size exceeding 100 nm and which is covered by a layer of titanium dioxide (Ti0 2 ) which in turn, is covered by a film of amorphus silicic acid, aluminium silicate or a metal oxide, such as aluminium oxide having a thickness of 1-100 nm, preferably 3-25 nm.
  • the core may consist of silicic acid, organic polymers, kaolin, atapulgite, b ⁇ hmite, bayerite or gibbsite.
  • the layer of titanium dioxide has a thickness of 10-100 nm.
  • the invention also comprises a method for the production of pigments having large light scattering ability and it is characterized in that a solution or dispersion of a titanium compound being hydrolysable in acid environment is added to a sole of colloidal core particles which do not consist of mica and which are substantially ball-shaped and have a particle size exceeding 100 nm, whereby, after completed hydrolysis when the core particles have been covered with a sealing layer of titanium dioxide, a film of an amorphus silicic acid, aluminium silicate or a metal oxide, such as aluminium oxide, having a thickness of 1-100 nm, preferably 3-25 nm, is applied at pH 8-11.
  • the titanium compound used may be an organic compound such as tetra alkyl titanates or tetraphenyl titanates, preferably tetra alkyl titanates containing alkyl chains having less than 18 carbon atoms, preferably less than 5 carbon atoms.
  • inorganic titanium compounds can also be used such as titanium chloride (TiCl 4 ) whereby HCl formed during the hydrolysis is continuously removed or neutralized.
  • TiCl 4 titanium chloride
  • the removal of hydrochloric acid can be carried out by rinsing through a membrane filter.
  • the film forming material consists of ionized alkali silicate.
  • Pigment particles according to the present invention are preferably ball-shaped and consist of an inner core on which a layer of titanium dioxide is covered. On this layer of colorant a film is arranged.
  • the core consists in preferred cases of silicic acid having a diameter less than 2000 nm. It may also consist of a polymer or some other solid substance.
  • the layer of titanium dioxide has normally a thickness of 5-100 nm whereas the film has a thickness of 1-100 nm, preferably 3-25 nm.
  • the film consists in preferred cases of amorphus silicic acid. Both the core, the titanium dioxide layer and the protecting film will be described below in more detail.
  • Cores according to the present invention are primarily solid materials having such properties that they can be dispersed to particles of colloidal size, which means less than 2000 nm, in water.
  • the cores should be solid substances consisting of inorganic or organic materials which are insoluble in water.
  • insoluble in water is meant that at most 0,1% of the material is soluble in water at 25°C.
  • Very suitable as cores according to the present invention are particles of silicic acid, particles of silicic acid the surface of which has been modified by aluminium so that strongly acid negatively charged sites of aluminium silicates are formed in the surface, and particles of aluminium silicate having a narrow size distribution of the particles centred in the range of ⁇ 2000 nm dispersed in water.
  • ⁇ 1000 nm dispersed in water particles of polymers produced through emulsion polymerization having a narrow distribution of particle size centred in the range of ⁇ 1000 nm dispersed in water.
  • Dispersions of this kind are usually called polymer latex when the particle size is in the range of 100-5000 nm.
  • These kind of dispersions of polymer particles have been produced by emulgating monomers to ultra fine droplets by means of emulsifying agents. After completed polymerization, the emulsifying agents remain attached on the surface of the polymer particles.
  • cores of silica soles which contain water sufficiently for hydrolysing and depositing of hydrolysable titanium compounds on the silicic acid are used. If an organic titanium compound is used it is of less importance whether this is added before or after the addition of a suitable amount of water in the sole.
  • the titanium compound may for example be added to a completely water free organosole and water can thereafter be added to the sole containing the titanium compound for hydrolysing of the titanium compound and covering thereof on the particles of the silicic acid. If for example 1 mole hydrolysable organic titanium compound is added to a water-free silicic acid sole, at least 1 ol water has to be added afterwards for hydrolysing of the titanium compound and fixing of it on the particles of the silicic acid.
  • the hydrolysable organic titanium compounds which may be used for covering the silicic acid particles may be chosen from a number of commercially available titanium compounds. Hydrolysable organic titanium compounds such as titanium alkoxides, complexis, polymers and salts of organic acids may be used. Titanium compounds containing nitrogen or silica or such having titanium-carbon bounds are also usable.
  • the preferred titanium compounds are titanium esters, especially tetra alkyl or tetra alkyl esters.
  • tetra substituted esters of titanium tetramethyltitanate examples include tetraethyltitanate, tetraisopropyl- titanate, tetraethenbutyltitanate and tetraphenyltitanate may be mentioned. Among these especially tetraisobutyl- titanate is preferred.
  • tetra alkyltitanates and tetraphenyltitanates.
  • tetra alkyltitanate containing alkyl chains which are shorter than 18 carbon atoms, preferably shorter than 5 carbon atoms, are preferred.
  • titanium compounds which are to be used according to the present invention Although it is a critical feature of the titanium compounds which are to be used according to the present invention that they shall be able to be hydrolysed to be fixed to the silicic acid particles, it is however not necessary that these titanium compounds are only monomer ic. Any titanium compound which can be hydrolysed further can be used. It has been shown that partially hydrolysed organic titanium compounds which can react further and polymerize after the hydrolysing also can be used according to the present invention.
  • partial prepolymers of titanium compounds such as tetra alkyltitanates can effectively cover the silicic acid particles with titanium dioxide.
  • Prepolymerized tetrabutyltitanatester can for instance be used.
  • a combination of partially hydrolysed or hydrolysable organic titanium compounds may be used as reactants when the silicic acid particles are covered.
  • the prepolymerized partially hydrolysed titanate esters may be combined with other monomeric hydrolyseable organic titanium compounds and thereafter be covered on the silicic acid particles.
  • an acid silicic acid sole is contacted with a hydrolysable organic titanium compound and thereafter heated to 50-100°C.
  • the resulting titanium silicic acid sole is then stable if it is maintained in this acid environment.
  • the silicic acid sole and the resulting titanium covered silicic acid is stabilized by an addition of some acid substance which lowers the pH in the sole mixture to below 2.
  • Mineral acids such as hydrochloric acid and nitric acid e t c are preferred.
  • further acid to maintain pH at or below this upper limit of 2.
  • the silicic acid sole is maintained at a pH from 0,5-2 until the addition of the organic titanium compound is complete.
  • a suitable titanium-covered silicic acid sole can be produced by addition of the whole amount of hydrolysable titanium compound in one go followed by heating of the solution in one step, it is preferred that the active titanium compound is divided in 2-4 equal parts. Each such part is added separately to this silicic acid sole and every addition is followed by a heating step. The number of heating steps depends on the number of portions of titanium which are added and which may vary from 2-4.
  • each part is added separately to the silicic acid sole and followed by a heating step which then will be three.
  • Each heating step is carried out at temperatures from 50-100°C, preferably 60-80°C.
  • the duration of the heating may vary from a quarter of an hour to three hours, preferably from half an hour to two hours.
  • the number of heating steps and corresponding addition portions of the titanium compounds depends on the amount of titanium which is to be covered on the silicic acid particles. It has been shown that long term stable titanium-covered silicic acid soles containing from 5-10% titanium (Ti0 2 ) based on the weight of the silicic acid (Si0 2 ) , can be produced by one single heating step. If 10- 20% titanium is wanted, two heating steps are preferred. If finally more than 20% titanium is wanted, at least three heating steps following each addition of equal parts of hydrolysable titanium compound are preferred.
  • the titanium compound it is suitable to vigorously stir the silicic acid sole in a suitable way.
  • the time for the addition of the titanium compound may vary depending on the size of the batch in question. The addition time varies usually from 5-60 minutes.
  • the stirring may be maintained up to one hour after completed addition of the titanium compound, but it is preferred that it is terminated in 1-10 minutes.
  • the hydrolysable organic titanium compound may be added as such in its natural physical shape or it can be dissolved in a suitable organic solvent in which it is not reactive.
  • the solvent which is to be used as carrier for the titanium compound must be free from every trace of water for avoiding hydrolysis and polymerization of the titanium compound before it comes into contact with the silicic acid sole.
  • Usual solvents such as methanol, ethanol, isopropylalcohol, buthanol and other organic alcohols may be used as solvents.
  • Benzene, toluene, xylene, e t c can also be used.
  • a titanium covered silicic acid sole can be produced which has in the dispersed phase titanium covered silicic acid particles in an amount of from 1,0-60% of the weight of the final sole.
  • Water or possible organic polar liquid can be used at the beginning of the continuous phase of the silicic acid sole or can be added later in the system. Mixtures of the above mentioned can also be used. Additionally, the final compositions can be concentrated by evaporation of the solvent in known ways.
  • inorganic titanium compounds such as titanium tetrachloride may be used for covering the silicic acid particles. It is then suitable that a dispersion of suitable cores is adjusted, for example silicic acid cores having a size of 200 nm in water, to pH of 0,5-1. The solid content of the dispersion may vary from 5-20 weight%.
  • TiCl 4 is added under vigorous stirring at a speed of 0,10-0,15 g TiCl 4 per hour and per gramme cores.
  • TiCl 4 is quickly hydrolysed to titanium dioxide and hydrochloric acid, HC1. It is essential that the HCl is removed at the same speed as it is formed so that pH is maintained at 0,5-1.
  • the first mono layer of Ti0 2 is formed by Ti-O-Si-bonds with the surface.
  • TiCl 4 results in Ti-O-Ti-bonds until all added Ti-atoms have been consumed.
  • the titanium dioxide covered silicic acid sole is finally covered with a film of, for example, silicic acid on the titanium dioxide layer.
  • the charge of the titanium dioxide covered silicic acid particles is positive at a pH of 0,5-2. This charge can be reversed by mixing the titanium dioxide covered silicic acid sole with a precalculated amount of a solution of water glass under vigorous stirring. When the addition is completed the mixture shall have a pH of 8-11. Active silicic acid in the form of de- ionized water glass of pH 2-3 is added to the now negatively charged sole of titanium dioxide covered silicic acid at a temperature of 80-100°C and pH 9-10. pH is maintained at 9-10 by adding either continuously or batchwise diluted sodiumhydroxide or a Na-silicate solution.
  • a critical step when covering titanium dioxide covered silicic acid sole is the recharging with de-ionized Na water glass. When this has been completed, every particle is surrounded by a thin layer of negatively charged silicic acid. Thereafter, the building of the film occurs in that monomeric silicic acid from the super saturated solution is deposited on and reacts with the first thin negatively charged layer of silicic acid.
  • Covering of titanium dioxide covered silicic acid soles can also start by raising the pH of the sole from 0,5-2 to 8-11 by addition of sodium hydroxide or a water glass solution. Thereafter, de-ionized Na water glass is added to the titanium dioxide covered sole during stirring in such a way that the temperature is maintained at 80-100°C and pH 8-11 and at such a speed that all added silicic acid is deposited, building a film on the surface of the particles of silicic acid soles covered with titanium dioxide and lasts until a film of the desired thickness has been built up.
  • An economically advantageous way to produce active silicic acid and to use it according to the present invention is partly to neutralize a soluble silicate such as sodium or potassium silicate with an acid such as sulphur acid or hydrochloric acid in the pH range of 8-11.
  • This acidifying occurs preferably in the presence of the titanium dioxide- covered particles of silicic acid which shall be provided with a film of silicic acid.
  • Production of active silicic acid can also occur in the absence of the titanium dioxide covered particles of silicic acid provided that the active silicic acid is added to these before they have become inactive by polymerizing to larger particles.
  • pH in the system should be maintained between 8 and 11. This can be done by addition of suitable proportions of either acid or a base depending on the ratio of alkali to silicic acid, Si0 2 in the alkali silicate used.
  • alkali metal ions should be kept below 0,3 M to avoid flocculating or coagulation.
  • active silicic acid is added in the form of freshly de-ionized alkali water glass, a control of the alkali metal ions does not create any problem.
  • active silicic acid is formed in situ by simultaneously adding acid and alkali metal silicate, it is desirable to use silicate having a ratio as high as possible and, if necessary, to dilute the reaction mixture to suppress the molarity of the alkali metal ions.
  • alkali metal ions can also be maintained below 0,3 M by instead of using an acid using a kation exchanging resin, preferably a strong one in hydrogen ion form which is filtered off when the addition of alkalimetal silicate has ceased.
  • a kation exchanging resin preferably a strong one in hydrogen ion form which is filtered off when the addition of alkalimetal silicate has ceased.
  • the temperature of the reaction mixture is preferably maintained between 80 and 100°C. At temperatures substantially below 80°C it can be difficult to build a film at a practical speed.
  • the speed at which the film is formed depends on pH, the content of alkali metal ions, the temperature and the specific surface of the titanium dioxide covered silicic acid particles.
  • the film of silicic acid is formed quickly at pH around 10 in the presence of sodium ions. Active silicic acid forms a film quicker at higher temperatures and the connection between speed and temperature can roughly be estimated by the observation that many reaction speeds are doubled for each increase of the temperature by 10°C in the above mentioned temperature range.

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  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Nanotechnology (AREA)
  • Composite Materials (AREA)
  • General Physics & Mathematics (AREA)
  • Materials Engineering (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Physics & Mathematics (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Dispersion Chemistry (AREA)
  • Pigments, Carbon Blacks, Or Wood Stains (AREA)

Abstract

L'invention concerne un pigment présentant des propriétés de dispersion élevée de la lumière. Ledit pigment est constitué d'un noyau de plus de 100 nm recouvert d'une couche d'étanchement de dioxyde de titane (TiO2) elle-même recouverte d'un film, par exemple, d'acide silicique amorphe. L'invention porte également sur un procédé de production d'un pigment présentant des propriétés de dispersion élevée de la lumière, qui consiste à enduire de dioxyde de titane les particules du noyau, se présentant sous forme de base, par hydrolyse des composés de titane, et à les recouvrir ensuite, par exemple, d'acide silicique obtenu à partir de silicate alcalin désionisé.
PCT/SE1994/000202 1993-03-15 1994-03-11 Pigments presentant de bonnes proprietes de dispersion de la lumiere Ceased WO1994021733A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
AU62938/94A AU6293894A (en) 1993-03-15 1994-03-11 Pigments having good scattering properties and process for the production thereof

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SE9300839-9 1993-03-15
SE9300839A SE501035C2 (sv) 1993-03-15 1993-03-15 Pigment med stor ljusspridningsförmåga samt sätt att framställa detsamma

Publications (1)

Publication Number Publication Date
WO1994021733A1 true WO1994021733A1 (fr) 1994-09-29

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Application Number Title Priority Date Filing Date
PCT/SE1994/000202 Ceased WO1994021733A1 (fr) 1993-03-15 1994-03-11 Pigments presentant de bonnes proprietes de dispersion de la lumiere

Country Status (3)

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AU (1) AU6293894A (fr)
SE (1) SE501035C2 (fr)
WO (1) WO1994021733A1 (fr)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5871872A (en) * 1997-05-30 1999-02-16 Shipley Company, Ll.C. Dye incorporated pigments and products made from same
US5885343A (en) * 1997-05-30 1999-03-23 Shipley Company, L.L.C. Dyed silica pigments and products made from same
DE19929109A1 (de) * 1999-06-24 2000-12-28 Merck Patent Gmbh Anorganische sphärische Absorptionspigmente
EP1431351A1 (fr) * 2002-12-17 2004-06-23 MERCK PATENT GmbH Pigments inorganiques et de forme sphérique
EP1132127A3 (fr) * 1996-03-12 2005-04-06 Berhan Tecle Procédé d'isolement de particules ultra-fines et fines et particules obtenues
DE102005022429A1 (de) * 2005-05-14 2006-11-16 Bene_Fit Gmbh Kornartiger Füllstoff zum weißen Einfärben von Verbundwerkstoffen und dessen Herstellungsverfahren
EP0949027A4 (fr) * 1996-06-10 2007-11-21 Nittetsu Mining Co Ltd Revetement de poudre a couches minces multiples et son procede de fabrication
CN103450712A (zh) * 2013-08-22 2013-12-18 丹东亿龙高科技材料有限公司 一种伊利石基复合钛白粉及其制备方法
CN107400380A (zh) * 2017-07-17 2017-11-28 西藏亚吐克工贸有限公司 高光泽漆专用二氧化钛制备方法
CN116425518A (zh) * 2021-12-31 2023-07-14 泉州市德化县恒峰陶瓷有限公司 一种着色稳定的无色差陶瓷及其制备方法

Citations (1)

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Cited By (12)

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Publication number Priority date Publication date Assignee Title
EP1132127A3 (fr) * 1996-03-12 2005-04-06 Berhan Tecle Procédé d'isolement de particules ultra-fines et fines et particules obtenues
EP0949027A4 (fr) * 1996-06-10 2007-11-21 Nittetsu Mining Co Ltd Revetement de poudre a couches minces multiples et son procede de fabrication
US5871872A (en) * 1997-05-30 1999-02-16 Shipley Company, Ll.C. Dye incorporated pigments and products made from same
US5885343A (en) * 1997-05-30 1999-03-23 Shipley Company, L.L.C. Dyed silica pigments and products made from same
DE19929109A1 (de) * 1999-06-24 2000-12-28 Merck Patent Gmbh Anorganische sphärische Absorptionspigmente
EP1431351A1 (fr) * 2002-12-17 2004-06-23 MERCK PATENT GmbH Pigments inorganiques et de forme sphérique
DE102005022429A1 (de) * 2005-05-14 2006-11-16 Bene_Fit Gmbh Kornartiger Füllstoff zum weißen Einfärben von Verbundwerkstoffen und dessen Herstellungsverfahren
DE102005022429B4 (de) * 2005-05-14 2009-04-02 Bene_Fit Gmbh Kornartiger Füllstoff zum weißen Einfärben von Verbundwerkstoffen und dessen Herstellungsverfahren
CN103450712A (zh) * 2013-08-22 2013-12-18 丹东亿龙高科技材料有限公司 一种伊利石基复合钛白粉及其制备方法
CN107400380A (zh) * 2017-07-17 2017-11-28 西藏亚吐克工贸有限公司 高光泽漆专用二氧化钛制备方法
CN107400380B (zh) * 2017-07-17 2019-03-26 西藏亚吐克工贸有限公司 高光泽漆专用二氧化钛制备方法
CN116425518A (zh) * 2021-12-31 2023-07-14 泉州市德化县恒峰陶瓷有限公司 一种着色稳定的无色差陶瓷及其制备方法

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SE501035C2 (sv) 1994-10-24
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SE9300839D0 (sv) 1993-03-15

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