EP0885265A1 - Mineral pigment microparticles covered with a chitin layer - Google Patents

Mineral pigment microparticles covered with a chitin layer

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Publication number
EP0885265A1
EP0885265A1 EP97947106A EP97947106A EP0885265A1 EP 0885265 A1 EP0885265 A1 EP 0885265A1 EP 97947106 A EP97947106 A EP 97947106A EP 97947106 A EP97947106 A EP 97947106A EP 0885265 A1 EP0885265 A1 EP 0885265A1
Authority
EP
European Patent Office
Prior art keywords
microparticles
chitin
chitosan
coated
pigments
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.)
Withdrawn
Application number
EP97947106A
Other languages
German (de)
French (fr)
Inventor
Bernard Grandmontagne
Bernard Brousse
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.)
Merck SA
Original Assignee
Merck SA
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 Merck SA filed Critical Merck SA
Publication of EP0885265A1 publication Critical patent/EP0885265A1/en
Withdrawn legal-status Critical Current

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Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01C—PLANTING; SOWING; FERTILISING
    • A01C1/00—Apparatus, or methods of use thereof, for testing or treating seed, roots, or the like, prior to sowing or planting
    • A01C1/06—Coating or dressing seed
    • 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
    • A61K8/11—Encapsulated compositions
    • 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
    • A61K8/73—Polysaccharides
    • A61K8/736—Chitin; Chitosan; Derivatives thereof
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61Q—SPECIFIC USE OF COSMETICS OR SIMILAR TOILETRY PREPARATIONS
    • A61Q1/00—Make-up preparations; Body powders; Preparations for removing make-up
    • A61Q1/02—Preparations containing skin colorants, e.g. pigments
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
    • B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
    • B01J13/02—Making microcapsules or microballoons
    • 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
    • C09C1/0015—Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings
    • 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
    • C09C1/0015—Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings
    • C09C1/0021—Pigments exhibiting interference colours, e.g. transparent platelets of appropriate thinness or flaky substrates, e.g. mica, bearing appropriate thin transparent coatings comprising a core coated with only one layer having a high or low refractive index
    • 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
    • C09C3/00—Treatment in general of inorganic materials, other than fibrous fillers, to enhance their pigmenting or filling properties
    • C09C3/10—Treatment with macromolecular organic compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D11/00—Inks
    • C09D11/02—Printing inks
    • C09D11/03—Printing inks characterised by features other than the chemical nature of the binder
    • C09D11/037—Printing inks characterised by features other than the chemical nature of the binder characterised by the pigment
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/60—Additives non-macromolecular
    • C09D7/61—Additives non-macromolecular inorganic
    • C09D7/62—Additives non-macromolecular inorganic modified by treatment with other compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
    • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
    • C09D7/40—Additives
    • C09D7/66—Additives characterised by particle size
    • C09D7/69—Particle size larger than 1000 nm
    • 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
    • A61K2800/41—Particular ingredients further characterized by their size
    • A61K2800/412—Microsized, i.e. having sizes between 0.1 and 100 microns
    • 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
    • A61K2800/42—Colour properties
    • A61K2800/43—Pigments; Dyes
    • 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
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/08—Ingredients agglomerated by treatment with a binding agent
    • 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
    • C09C2200/00—Compositional and structural details of pigments exhibiting interference colours
    • C09C2200/40—Interference pigments comprising an outermost surface coating
    • C09C2200/402—Organic protective coating
    • C09C2200/405—High molecular weight materials, e.g. polymers
    • 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
    • C09C2220/00—Methods of preparing the interference pigments
    • C09C2220/10—Wet methods, e.g. co-precipitation

Definitions

  • the present invention relates to new microparticles of mineral pigments coated with a layer of chitin or of chitin derivatives and a process for the preparation of microparticles of mineral pigments coated with a layer of chitin or of derivatives of chitin.
  • microparticles of coated mineral pigments obtained in particular by said process and the use of these microparticles of coated mineral pigments as a film-forming substance or for the granulation of various products.
  • It relates in particular to new aggregated or compacted forms obtained from these microparticles, with rapid disintegration and with high load capacity, in particular useful for conveying active substances, for example phytosanitary.
  • Mineral pigments are an important part of the dye industry. Directly derived from oxide chemistry, they provide color and are easy to access. Nevertheless, they sometimes suffer from formulation difficulties and are then replaced by organic pigments having other processing qualities. The deposition of an organic surface film could in some cases overcome the difficulty and be economically or technically a more attractive solution.
  • the coating of the pigments can be carried out by various techniques. For the vast majority of them, it involves depositing on the surface of a pigmentary particle, a polymer in the course of drying, condensation or polycondensation. This mode of action is used in particular to coat the pigments with polysaccharides.
  • Japanese document JP-A-63027501 describes nanoparticles of titanium oxide superfine powder embedded in a chitin or chitosan gel. It is a gel-like structure which does not lead to the formation of coated and individualized nanoparticles.
  • Japanese document JP-A-62223108 describes cosmetic pigments coated with a layer of chitosan. Such a document does not describe a process for the preparation of pigments coated with a layer of chitin.
  • Chitin is the structural polymer of arthropods, crustaceans and insects and is part of the membrane of certain fungi. It maintains the endoskeleton of the cephalopods. It is in the animal world the counterpart of what is cellulose in the vegetable kingdom.
  • Patent application EP-A-0 021 750 describes a process for the preparation of chitin by acetylation of deacetylated chitin in the presence of an organic acid anhydride and a suspending agent such as a sorbitan monoester.
  • Patent application EP-A-0 026 618 describes a material comprising a mixture of two or more etherified chitin derivatives obtained by the same acetylation process indicated for the two aforementioned documents.
  • the spherical materials obtained can be used in particular as ion exchange resins.
  • the transformation of chitosan into chitin is a reaction which requires the simultaneous presence of two solvents.
  • Water ensures the solvation of chitosan salts at a pH below 6.5.
  • the chitosan salts are in particular the organic acid salts such as acetic acid or oxalic acid, mineral acid salts such as hydrochloric acid, in sufficient concentration to obtain the chitosan in salified form.
  • the second solvent is a water-soluble organic derivative such as alcohol, tetrahydrofuran, dioxane in an amount sufficient to allow the dissolution of an organic anhydride of acetylated type and whose role is the acetylation of the amino groups of chitosan. Used in the presence of chitosan, this reaction results, if the anhydride is acetic, in chitin.
  • the method according to the invention therefore allows the coating of particles and not the solidification due to the formation of gel.
  • the inventors have observed that the new microparticles, which are new in themselves, lead to aggregated or compacted forms having remarkable properties with regard to their disintegration capacity in solution, their high load capacity and therefore their ability to transport particularly toxic substances such as phytosanitary products.
  • the invention relates to a process for the preparation of microparticles of mineral pigments coated with a layer of chitin or derivatives of chitin, characterized in that: a) microparticles of mineral pigments in suspension are brought into contact with a solution of salified chitosan or of salified chitosan derivatives so as to cause the deposition of salified chitosan or salified chitosan derivatives around the pigment microparticles, b) the pigment microparticles coated with chitosan or salified chitosan derivatives are then subjected to a reaction acetylation using organic acid anhydride.
  • Chitosan is a polymer of D-glucosamine with a ⁇ , 1-4 chain as shown in the single figure appended to the present description.
  • R represents at least one group chosen from the carboxyalkyl group of 2 to 4 carbon atoms, a hydroxyethyl group, a hydroxypropyl group, a dihydroxypropyl group or an alkyl group of 1 to 3 carbon atoms, x_ being a number between 0.1 and 1, y being equal to 1, 0 - x, a is a number between 0.1 and 1 and b being equal to 1, 0 - a where a salified form of these compounds.
  • Chitin or poly N-acetyl-D-glucosamine is a polysaccharide whose units are linked together by ⁇ -1, 4 glycosidic bridges. It is therefore distinguished from chitosan which is an N-deacetylated chitin. When the deacetylation is complete, a singular chitosan is obtained, the polyglucosamine.
  • Chitin is naturally deacetylated above 5% and more.
  • the term chitosan is reserved for derivatives which, having undergone deacetylation, become soluble in an acidic aqueous medium. This requires a degree of deacetylation at least greater than 65%. This rate will influence the physical properties of chitosan, solubility and viscosity, but also on its biochemical behavior.
  • the concentration of salified chitosan or salified chitosan derivatives in the solution is such that it is lower than the critical miscellar concentration.
  • this concentration which is necessarily low, depends on the agitation applied of the particles used, on their interaction with chitosan or chitosan derivatives, and on the concentration of the particles themselves.
  • the concentration of particles in the suspension as well as the concentration of salified chitosan or salified chitosan derivatives in the solution must be such that a deposit of chitosan or chitosan derivatives is produced by adsorption on the surface of the particles. particles unlike the formation of a gel which leads to non-individualized particles.
  • the particle size of the mineral pigment particles is micrometric generally between 1 and 200 ⁇ m, generally 1 to 100 ⁇ m, preferably greater than 5 ⁇ m, advantageously 5 to 60 ⁇ m although these limits do not limit the scope of the present invention.
  • the concentration of pigments in suspension is generally between 0.4 and 40 g / l.
  • mineral pigments mention will preferably be made of titanium mica or metal oxides, in particular pearlescent pigments of the Iriodine®, Florapearl® 10 and 12 type and pigments of the Iriodione® range.
  • the salified forms of chitosan or derivatives of chitosan there may be mentioned in particular the organic acid salts such as acetic acid or oxalic acid and the mineral acid salts such as hydrochloric acid.
  • organic acid salts such as acetic acid or oxalic acid
  • mineral acid salts such as hydrochloric acid.
  • chitosan acetate or the acetates of chitosan derivatives Preferably, mention is made of chitosan acetate or the acetates of chitosan derivatives.
  • the microparticles of mineral pigments are suspended in a hydroalcoholic solution.
  • the suspension is maintained by stirring.
  • the water: alcohol mixture can vary within wide proportions such that the water: alcohol ratio is between 0.25 and 4 or even 20/80 and 80/20.
  • the alcohol may be a saturated or unsaturated mono or polyalcohol, although it is desirable that the alcohol chosen is among the least reactive with respect to the organic anhydride in order to avoid any parasitic reaction.
  • secondary alcohols of the isopropanol or isobutanol type are chosen.
  • the suspension is first carried out with agitation of pigmentary particles in the hydroalcoholic phase, leaving the suspension in the state sufficient time to allow the boiling then the chitosan solution or salified chitosan derivatives are added thereto.
  • the pH of the solution of salified chitosan or derivatives of salified chitosan is generally between 2 and 6 depending on the salified form chosen. In the case of chitosan acetate or acetate of chitosan derivatives, the pH is generally between 4 and 4.5.
  • the concentration of chitosan or salified chitosan derivatives is between 0.005 and 0.5 g / l, advantageously between 0.01 and 0.1 g / l.
  • the solution is left under stirring for a sufficient time for adsorption or for the initial inking of the chitosan chains or chitosan derivatives on the surface of the pigments and in the case of pigments coated with titanium mica to the fixing of chitosan to titanium either by chelation, or by complexation.
  • the acetylation reaction is carried out by adding a solution of an organic acid anhydride in an alcohol.
  • the alcohol will preferably be a secondary alcohol such as isopropanol or isobutanol.
  • acetic anhydride is preferably chosen.
  • the concentration of organic acid anhydride, in particular acetic anhydride, is between 0.1 and 10 g / l, preferably between 0.5 and 5 g / l.
  • the quantity of the different reagents involved is given below, it being understood that this variant is given only for information and cannot in any way limit the method according to the invention. from to preferably
  • step a) is carried out in the presence of one or more compounds of organic interest such as an active molecule, which will allow a controlled release of this molecule (delay effect) when the microcapsules of mineral pigments obtained have been included in an appropriate medium.
  • active molecules mention may be made of pharmaceutical molecules, phytosanitary molecules, various saturated or unsaturated fatty acids, branched or not, such as octylcarboxylic acid.
  • these molecules are included in the chitin wall in small quantities so as not to interfere with the cohesion of the chitin film.
  • the invention also relates to new microparticles of mineral pigments characterized in that they are coated with a layer of chitin or derivatives of chitin, said layer possibly comprising one or more organic substances. Said coated microparticles are capable of being obtained by the method according to the invention.
  • coated microparticles have a particle size which of course depends on the particle size of the microparticles of the suspended mineral pigments.
  • coated microparticles according to the invention have surface film-forming properties. Therefore, the particles can form on the one hand dry films without providing viscosity to the processing solution.
  • the pigments can serve as a support skeleton for any formulation and allow it to be molded in the most diverse forms (granulation).
  • microparticles according to the invention therefore have the advantage of being able to be used in an extremely wide manner, in particular as a film-forming substance or for the granulation of products such as toxic products or bacteria.
  • the chitin layer comprises organic molecules, for example pharmaceutical, phytosanitary, cosmetic, etc.
  • the film-forming applications the following are cited: the coating of seeds, the coating of pebbles or tablets, for example tablets made effervescent, the use of microparticles in various printing ink formulations, in particular in the OFFSET process, in heliography or flexography.
  • microparticles As another film-forming application, mention is made of the use of these microparticles in paint formulations, in particular vinyl, acrylic, but also glycerophthalic.
  • the addition of such microparticles leads to film deposits with increased covering effect.
  • One of the particularly remarkable and unexpected characteristics of the present invention therefore lies in the fact that these coated microparticles make it possible to obtain new compacted or aggregated forms with rapid disintegration.
  • These compacted forms have a density much less than 1, in particular of the order of about 0.2 and can be in the form of rollers. They can contain a significant charge of active substance, in particular phytosanitary substances, such as imidachloprid.
  • the compacts can be obtained from pigments coated with chitin or these derivatives as already described.
  • the coating can be from 0.1 to 10% of chitin but preferably from 0.3 to 3%. The characteristics of the compacts obtained for these concentrations are similar and described in the following table.
  • a compacting technique consists in hydrating the microparticles of coated pigments with an amount of water less than the amount necessary for their resuspension in liquid. This amount is of the order of twice the weight of the microparticles of dry coated pigments. This system during drying aggregates without significant variations in volume. If other compounds are added to the aqueous phase, these are trapped during drying in the structure of the three-dimensional network of pearlescent pigments.
  • microparticles of mineral pigments according to the invention can also be used in the granulation of various products in aggregated or compacted form: the toxic products mixed with the microparticles according to the invention, after drying, form a pebble which limits the toxic effect of powdery treatment product.
  • This roller can then be used by simple mixing with water or it disintegrates without viscosing the medium.
  • the granulation of bacteria in microparticles according to the invention is also an easy solution to the difficulties which are generally encountered in the use of bacterial systems in biotechnological applications. We know indeed the difficulties of conservation of the strains in their transport and in their implementation.
  • microparticles according to the invention in which the chitin layer comprises one or more active substances can be released in a controlled manner.
  • the release factors are generally the humidity of the medium, the pH, the biodegradation of the system.
  • Other uses can also be envisaged such as the compacting of dyes, pigments or even perfumes.
  • the pleasant touch of the microparticles according to the invention allows their use in the dry formulation of the cosmetic industries (foundation).
  • the mixture is stirred for two hours for maximum adsorption of the chitosan on the pigments.
  • Example 2 Coating of Iriodine® 111 pearlescent pigments (particle size 1 to 15 ⁇ m)
  • Example 1 The operating conditions of Example 1 are reproduced and lead to the corresponding pigments.
  • a corn coating solution is produced by mixing 30 parts by weight of pigments from Example 1 previously coated with 1% chitin, 60 parts of conventional plant protection products and 90 parts of water to ensure wetting.
  • This solution commonly called porridge is stirred in the presence of corn or sprayed on it at the rate of 2 kg per 100 kg of corn.
  • the absorption of water by corn seeds causes the deposition of porridge which is deposited on the surface of the seed.
  • the film-forming maintenance of the formula is ensured by the coated pigments.
  • a part of coated pigments, hydrated beforehand, at 20% is sprinkled on 100 parts of a composition having the form of pebbles or tablets made effervescent in water by their emission of CO 2 .
  • the coated pigments are deposited to form a protective film on the surface of the tablets.
  • a preparation with 30 parts of pigments in a paint formulation leads in vinyl solvent, acrylic but also in glycerophatic medium to film deposits with increased covering effect.
  • the compacting technique consists in hydrating the coated pigments with an amount of water less than the amount necessary for their resuspension in liquid. This amount is of the order of twice the weight of the microparticles of dry coated pigments. This system during drying aggregates without significant variations in volume. If other compounds are added to the aqueous phase, these are trapped during drying in the structure of the three-dimensional network of pearlescent pigments.
  • coated florapearl 12® are mixed with 50 of phytosanitary product.
  • the dried whole forms a pebble which limits the powdery toxic effect of the treatment product.
  • This roller can then be used by simple mixing with water where it disintegrates without viscosing the medium.
  • Florapearl 12® is Iriodine®, micatitane reference Iriodine® 120, called Florapearl® for its application in seeds.
  • Rhizobium Bacteria A culture of Rhizobium is carried out beforehand. It is directly mixed in equal proportion with coated pigments previously sterilized by irradiation. After drying by an appropriate method, in molds, the rollers obtained are kept in a sterile environment and then tested for their ability to cause nodulations after 1, 2, 6, 9, 12 months and successfully compared with controls fixed on various other media.
  • a culture of Azospirillium and a culture of Speudomonas could be preserved by the same methods to promote biological control. Their application is made in granules at the direct periphery of the treated plants.
  • the pigment microparticles can be coated with a more or less high content of chitin.
  • a number of parameters will depend on this quantity.
  • an active molecule comprising binding sites sensitive to hydrogen bonds such as most conventional organic molecules is trapped in the nascent chitin or in the granules in formation, their release in time can be mastered.
  • the release factors will then be the humidity of the medium, the pH, the biodegradation of the system. This technique has been used on various saturated or unsaturated fatty acids, branched or not.
  • octylcarboxylic acid trapped at 1% in a pebble 5 cm in diameter and 1 cm thick and kept under running water, completely releases (loss of spectrographic signal) in three weeks.
  • Compaction can be used to maintain dyes, pigments or even perfumes. Its pleasant touch allows it to be used in the dry formulation of the cosmetic industries (foundation, etc.).
  • the attached single figure is a microscopic photograph of a titanium oxide mica pigment coated with chitin (length of the pigment approximately 50 ⁇ r ⁇ ).

Abstract

The invention concerns mineral pigment microparticles, characterised in that they are covered with a chitin or chitin derivative layer optionally containing one or several organic substances. The invention also concerns the compacted forms of these microparticles, with fast splitting, optionally filled with an active, in particular phytosanitary, substance. The invention finally concerns a method for preparing mineral pigment microparticles covered with a chitin or chitin derivative layer characterised in that a) mineral pigment microparticles in suspense are contacted with a solution of salified chitosan or chitosan derivatives so as to cause the coacervation of the chitosan or the chitosan derivatives around the pigment microparticles, b) the covered microparticles are then subjected to an acetylation reaction.

Description

MICROPARTICULES DE PIGMENTS MINERAUX ENROBEES D'UNE COUCHE DE CHITINEMICROPARTICLES OF MINERAL PIGMENTS COATED WITH A CHAIN LAYER
La présente invention concerne de nouvelles microparticules de pigments minéraux enrobées d'une couche de chitine ou de dérivés de chitine et un procédé de préparation de microparticules de pigments minéraux enrobées d'une couche de chitine ou de dérivés de chitine.The present invention relates to new microparticles of mineral pigments coated with a layer of chitin or of chitin derivatives and a process for the preparation of microparticles of mineral pigments coated with a layer of chitin or of derivatives of chitin.
Elle concerne également les microparticules de pigments minéraux enrobées obtenues notamment par ledit procédé et l'utilisation de ces microparticules de pigments minéraux enrobées comme substance filmogène ou pour la granulation de produits variés.It also relates to the microparticles of coated mineral pigments obtained in particular by said process and the use of these microparticles of coated mineral pigments as a film-forming substance or for the granulation of various products.
Elle concerne en particulier de nouvelles formes agrégées ou compactées obtenues à partir de ces microparticules, à délitement rapide et à capacité de charge élevée, notamment utiles pour véhiculer des substances actives, par exemple phytosanitaires.It relates in particular to new aggregated or compacted forms obtained from these microparticles, with rapid disintegration and with high load capacity, in particular useful for conveying active substances, for example phytosanitary.
Les pigments minéraux sont une part importante de l'industrie des colorants. Directement issus de la chimie des oxydes, ils apportent la couleur et sont d'un accès économique aisé. Néanmoins, ils souffrent parfois de difficultés de formulation et sont alors supplantés par des pigments organiques présentant d'autres qualités de mise en oeuvre. Le dépôt d'une pellicule organique de surface pourrait dans certains cas, pallier la difficulté et être économiquement ou techniquement, une solution plus attractive.Mineral pigments are an important part of the dye industry. Directly derived from oxide chemistry, they provide color and are easy to access. Nevertheless, they sometimes suffer from formulation difficulties and are then replaced by organic pigments having other processing qualities. The deposition of an organic surface film could in some cases overcome the difficulty and be economically or technically a more attractive solution.
L'enrobage des pigments peut être réalisé par diverses techniques. Pour la grande majorité d'entre-elles, il s'agit de déposer à la surface d'une particule pigmentaire, un polymère en cours de séchage, de condensation ou de polycondensation. Ce mode d'action est utilisé en particulier pour enrober les pigments par des polysaccharides.The coating of the pigments can be carried out by various techniques. For the vast majority of them, it involves depositing on the surface of a pigmentary particle, a polymer in the course of drying, condensation or polycondensation. This mode of action is used in particular to coat the pigments with polysaccharides.
De nombreux travaux ont d'ores et déjà été réalisés sur l'enrobage par les polysaccharides. Des techniques de condensations ioniques ou de réticulation de chaînes permettent en particulier un dépôt de polymère organique sur une surface minérale. Néanmoins, si une vision macroscopique permet de parler d'enrobage lorsqu'une condensation se fait en présence de pigments, une étude microscopique laisse souvent entrevoir un amas de particules agrégées par le polymère loin d'être un véritable film recouvrant la surface de particules individualisées.Numerous studies have already been carried out on the coating with polysaccharides. Techniques of ionic condensations or of crosslinking of chains allow in particular a deposit of organic polymer on a mineral surface. However, if a macroscopic vision makes it possible to speak of coating when a condensation takes place in the presence of pigments, a microscopic study often suggests a cluster of particles aggregated by the polymer far from being a real film covering the surface of individual particles .
On a notamment observé que, lorsque de tels procédés sont appliqués à l'enrobage de particules pigmentaires par de la chitine, la réacétylation conduisait à la formation d'un gel dans lequel des particules pigmentaires étaient noyées et non à des particules individualisées enrobées de chitine.In particular, it has been observed that, when such methods are applied to the coating of pigment particles with chitin, the reacetylation leads to the formation of a gel in which the pigment particles are embedded and not to individual particles coated with chitin .
Le document japonais JP-A-63027501 décrit des nanoparticules de poudre superfine d'oxyde de titane noyées dans un gel de chitine ou de chitosane. Il s'agit d'une structure de type gel qui ne conduit pas à la formation de nanoparticules enrobées et individualisées. Le document japonais JP-A-62223108 décrit des pigments cosmétiques enrobés d'une couche de chitosane. Un tel document ne décrit pas un procédé de préparation de pigments enrobés d'une couche de chitine.Japanese document JP-A-63027501 describes nanoparticles of titanium oxide superfine powder embedded in a chitin or chitosan gel. It is a gel-like structure which does not lead to the formation of coated and individualized nanoparticles. Japanese document JP-A-62223108 describes cosmetic pigments coated with a layer of chitosan. Such a document does not describe a process for the preparation of pigments coated with a layer of chitin.
La chitine est le polymère de structure des arthropodes, crustacés et insectes et fait partie de la membrane de certains champignons. Elle assure la tenue de l'endosquelette des céphalopodes. Elle est au monde animal le pendant de ce qu'est la cellulose au règne végétal.Chitin is the structural polymer of arthropods, crustaceans and insects and is part of the membrane of certain fungi. It maintains the endoskeleton of the cephalopods. It is in the animal world the counterpart of what is cellulose in the vegetable kingdom.
Sa particularité réside dans son inertie chimique. Peu réactive, insoluble dans la plupart des solvants organiques connus, elle ne peut, non plus, être thermoformée. Ce n'est qu'en la transformant en chitosane qu'il devient possible de la mettre en oeuvre.Its particularity lies in its chemical inertness. Not very reactive, insoluble in most known organic solvents, it cannot be thermoformed either. It is only by transforming it into chitosan that it becomes possible to use it.
Pour moduler la chitine, il est nécessaire de procéder en deux étapes. La première consiste à transformer la chitine en chitosane puis la seconde à retransformer le chitosane en chitine. Il est ainsi décrit dans la demande de brevet EP-A-0 013 181 , page 2, une préparation de chitine par N-acétylation de chitosane avec de l'anhydride acétique dans une solution de pyridine ou une solution d'acide perchlorique. Des dérivés de chitine ont également été préparés. La demande de brevet EP-A-0 013 181 décrit la préparation de N-acétyl carboxyalkylchitine par acétylation de carboxyalkylchitine déacétylée avec un anhydride d'un acide organique. D'autres dérivés de chitine sont également mentionnés tels que les hydroxyalkylchitines. Le matériau obtenu peut être mis sous la forme de particules sphériques utilisables comme résines échangeuses d'ions.To modulate chitin, it is necessary to proceed in two stages. The first consists in transforming chitin into chitosan then the second in transforming chitosan into chitin. It is thus described in patent application EP-A-0 013 181, page 2, a preparation of chitin by N-acetylation of chitosan with acetic anhydride in a solution of pyridine or a solution of perchloric acid. Chitin derivatives have also been prepared. Patent application EP-A-0 013 181 describes the preparation of N-acetyl carboxyalkylchitine by acetylation of deacetylated carboxyalkylchitine with an anhydride of an organic acid. Other chitin derivatives are also mentioned such as hydroxyalkylchitines. The material obtained can be in the form of spherical particles which can be used as ion exchange resins.
La demande de brevet EP-A-0 021 750 décrit un procédé de préparation de chitine par acétylation de chitine déacétylée en présence d'un anhydride d'acide organique et d'un agent de suspension tel qu'un monoester de sorbitan.Patent application EP-A-0 021 750 describes a process for the preparation of chitin by acetylation of deacetylated chitin in the presence of an organic acid anhydride and a suspending agent such as a sorbitan monoester.
La demande de brevet EP-A-0 026 618 décrit un matériau comprenant un mélange de deux ou plus dérivés de chitine éthérifiés obtenus par le même procédé d'acétylation indiqué pour les deux documents précités. Les matériaux sphériques obtenus peuvent être notamment utilisés comme résines échangeuses d'ions.Patent application EP-A-0 026 618 describes a material comprising a mixture of two or more etherified chitin derivatives obtained by the same acetylation process indicated for the two aforementioned documents. The spherical materials obtained can be used in particular as ion exchange resins.
De manière générale, la transformation de chitosane en chitine est une réaction qui nécessite la présence simultanée de deux solvants. L'eau assure la solvatation des sels de chitosane à pH inférieur à 6,5. Les sels de chitosane sont notamment les sels d'acide organique tels que l'acide acétique ou l'acide oxalique, des sels d'acide minéraux tels que l'acide chlorhydrique, en concentration suffisante pour obtenir le chitosane sous forme salifiée. Le second solvant est un dérivé organique hydrosoluble tel que l'alcool, le tétrahydrofuranne, le dioxane en quantité suffisante pour permettre la mise en solution d'un anhydride organique de type acétylé et dont le rôle est l'acétylation des groupements aminés du chitosane. Utilisée en présence de chitosane, cette réaction aboutit, si l'anhydride est acétique, à la chitine.In general, the transformation of chitosan into chitin is a reaction which requires the simultaneous presence of two solvents. Water ensures the solvation of chitosan salts at a pH below 6.5. The chitosan salts are in particular the organic acid salts such as acetic acid or oxalic acid, mineral acid salts such as hydrochloric acid, in sufficient concentration to obtain the chitosan in salified form. The second solvent is a water-soluble organic derivative such as alcohol, tetrahydrofuran, dioxane in an amount sufficient to allow the dissolution of an organic anhydride of acetylated type and whose role is the acetylation of the amino groups of chitosan. Used in the presence of chitosan, this reaction results, if the anhydride is acetic, in chitin.
Toutes ces techniques sont en général fort connues. On en trouvera notamment des exemples dans les documents mentionnés ci-dessus.All of these techniques are generally well known. Examples can be found in the documents mentioned above.
De manière surprenante, les inventeurs ont observé que dans des conditions particulières, il était possible d'obtenir l'enrobage de particules pigmentaires par du chitosane, tout en laissant ces particules sous forme individualisée puis par réacétylation, d'obtenir des microparticules pigmentaires enrobées de chitine.Surprisingly, the inventors have observed that under particular conditions, it was possible to obtain the coating of pigment particles with chitosan, while leaving these particles in the form individualized then by reacetylation, to obtain pigmentary microparticles coated with chitin.
Le procédé selon l'invention permet donc l'enrobage de particules et non pas la prise en masse due à la formation de gel. De manière surprenante encore, les inventeurs ont observé que les nouvelles microparticules, qui sont nouvelles en soi, conduisaient à des formes agrégées ou compactées présentant des propriétés remarquables en ce qui concerne leur capacité de délitement en solution, leur capacité de charge élevée et donc leur aptitude à véhiculer des substances notamment toxiques comme les produits phytosanitaires.The method according to the invention therefore allows the coating of particles and not the solidification due to the formation of gel. Again surprisingly, the inventors have observed that the new microparticles, which are new in themselves, lead to aggregated or compacted forms having remarkable properties with regard to their disintegration capacity in solution, their high load capacity and therefore their ability to transport particularly toxic substances such as phytosanitary products.
D'autres objets et avantages de la présente invention seront décrits au cours de l'exposé qui suit :Other objects and advantages of the present invention will be described during the following description:
En premier lieu, l'invention concerne un procédé de préparation de microparticules de pigments minéraux enrobées d'une couche de chitine ou dérivés de chitine, caractérisé en ce que : a) des microparticules de pigments minéraux en suspension sont mises en contact avec une solution de chitosane salifié ou de dérivés de chitosane salifiés de façon à provoquer le dépôt du chitosane salifié ou des dérivés de chitosane salifiés autour des microparticules de pigments, b) les microparticules de pigments enrobées de chitosane ou dérivés de chitosane salifiés sont ensuite soumises à une réaction d'acétylation au moyen d'anhydride d'acide organique.Firstly, the invention relates to a process for the preparation of microparticles of mineral pigments coated with a layer of chitin or derivatives of chitin, characterized in that: a) microparticles of mineral pigments in suspension are brought into contact with a solution of salified chitosan or of salified chitosan derivatives so as to cause the deposition of salified chitosan or salified chitosan derivatives around the pigment microparticles, b) the pigment microparticles coated with chitosan or salified chitosan derivatives are then subjected to a reaction acetylation using organic acid anhydride.
Le chitosane est un polymère de D-glucosamine à enchaînement β,1-4 tel qu'il est représenté à la figure unique annexée à la présente description.Chitosan is a polymer of D-glucosamine with a β, 1-4 chain as shown in the single figure appended to the present description.
Parmi les dérivés de chitosane convenant, on cite notamment les dérivés O-éthérifié ou O-estérifié du type correspondant à la formule I ci- dessous :Among the suitable chitosan derivatives, there may be mentioned in particular the O-etherified or O-esterified derivatives of the type corresponding to formula I below:
[C6H8θ3.(NH2)x.(NHCOCH3)y.(OR)a.(OH)b]n dans laquelle :[C 6 H 8 θ3. (NH 2 ) x . (NHCOCH 3 ) y. (OR) a . (OH) b] n in which:
R représente au moins un groupe choisi parmi le groupe carboxyalkyle de 2 à 4 atomes de carbone, un groupe hydroxyéthyle, un groupe hyroxypropyle, un groupe dihydroxypropyle ou un groupe alkyle de 1 à 3 atomes de carbone, x_étant un nombre compris entre 0,1 et 1 , y étant égal à 1 ,0 - x, a est un nombre compris entre 0,1 et 1 et b étant égal à 1 ,0 - a où une forme salifiée de ces composés.R represents at least one group chosen from the carboxyalkyl group of 2 to 4 carbon atoms, a hydroxyethyl group, a hydroxypropyl group, a dihydroxypropyl group or an alkyl group of 1 to 3 carbon atoms, x_ being a number between 0.1 and 1, y being equal to 1, 0 - x, a is a number between 0.1 and 1 and b being equal to 1, 0 - a where a salified form of these compounds.
La chitine ou poly N-acétyl-D-glucosamine est un polysaccharide dont les unités sont liées entre elles par des ponts β-1 ,4 glycosidiques. Elle se distingue donc du chitosane qui est une chitine N- désacétylée. Lorsque la desacetylation est totale, on obtient un chitosane singulier, le polyglucosamine.Chitin or poly N-acetyl-D-glucosamine is a polysaccharide whose units are linked together by β-1, 4 glycosidic bridges. It is therefore distinguished from chitosan which is an N-deacetylated chitin. When the deacetylation is complete, a singular chitosan is obtained, the polyglucosamine.
La chitine est naturellement désacétylée au-dessus de 5% et plus. Le terme de chitosane est réservé aux dérivés qui, ayant subi une desacetylation, deviennent solubles en milieu aqueux acide. Il faut pour ce faire un degré de desacetylation au moins supérieur à 65%. Ce taux influera sur les propriétés physiques du chitosane, solubilité et viscosité, mais également sur son comportement biochimique.Chitin is naturally deacetylated above 5% and more. The term chitosan is reserved for derivatives which, having undergone deacetylation, become soluble in an acidic aqueous medium. This requires a degree of deacetylation at least greater than 65%. This rate will influence the physical properties of chitosan, solubility and viscosity, but also on its biochemical behavior.
La concentration de chitosane salifié ou de dérivés de chitosane salifiés dans la solution est telle qu'elle est inférieure à la concentration miscellaire critique.The concentration of salified chitosan or salified chitosan derivatives in the solution is such that it is lower than the critical miscellar concentration.
La valeur de cette concentration, nécessairement faible, dépend de l'agitation appliquée des particules utilisées, de leur interaction avec le chitosane ou dérivés de chitosane, et de la concentration des particules elles-mêmes.The value of this concentration, which is necessarily low, depends on the agitation applied of the particles used, on their interaction with chitosan or chitosan derivatives, and on the concentration of the particles themselves.
En tout état de cause, la concentration de particules dans la suspension ainsi que la concentration de chitosane salifié ou dérivés de chitosane salifiés dans la solution doit être telle qu'il se produit un dépôt de chitosane ou dérivés de chitosane par adsorption à la surface des particules à la différence de la formation d'un gel qui conduit à des particules non individualisées.In any event, the concentration of particles in the suspension as well as the concentration of salified chitosan or salified chitosan derivatives in the solution must be such that a deposit of chitosan or chitosan derivatives is produced by adsorption on the surface of the particles. particles unlike the formation of a gel which leads to non-individualized particles.
La granulométrie des particules de pigments minéraux est micrométrique généralement comprise entre 1 et 200 μm, généralement 1 à 100 μm, de préférence supérieure à 5 μm, avantageusement 5 à 60 μm bien que ces bornes ne limitent pas la portée de la présente invention. La concentration des pigments en suspension est généralement comprise entre 0,4 et 40 g/l. Ces microparticules se distinguent donc fondamentalement des nanoparticules décrites dans le brevet japonais JP-A-63027501.The particle size of the mineral pigment particles is micrometric generally between 1 and 200 μm, generally 1 to 100 μm, preferably greater than 5 μm, advantageously 5 to 60 μm although these limits do not limit the scope of the present invention. The concentration of pigments in suspension is generally between 0.4 and 40 g / l. These microparticles are therefore fundamentally different from the nanoparticles described in Japanese patent JP-A-63027501.
Parmi les pigments minéraux on citera de préférence, le mica titane ou les oxydes métalliques notamment les pigments nacrés du type Iriodine®, Florapearl® 10 et 12 et les pigments de la gamme Iriodione®. Parmi les formes salifiées de chitosane ou dérivés de chitosane, on cite notamment les sels d'acide organique tels que l'acide acétique ou l'acide oxalique et les sels d'acide minéraux tels que l'acide chlorhydrique. De préférence, on cite l'acétate de chitosane ou les acétates de dérivés de chitosane. L'invention est maintenant décrite selon des variantes préférées qui sont soit prises en combinaison partiellement ou totalement entre elles, soit prises individuellement en liaison avec la définition générale de l'invention indiquée ci-dessus.Among the mineral pigments, mention will preferably be made of titanium mica or metal oxides, in particular pearlescent pigments of the Iriodine®, Florapearl® 10 and 12 type and pigments of the Iriodione® range. Among the salified forms of chitosan or derivatives of chitosan, there may be mentioned in particular the organic acid salts such as acetic acid or oxalic acid and the mineral acid salts such as hydrochloric acid. Preferably, mention is made of chitosan acetate or the acetates of chitosan derivatives. The invention is now described according to preferred variants which are either taken in combination partially or completely between them, or taken individually in conjunction with the general definition of the invention indicated above.
- Les microparticules de pigments minéraux sont mises en suspension dans une solution hydroalcoolique. La suspension est maintenue par agitation. Le mélange eau:alcool peut varier dans de larges proportions telles que le rapport eau:alcool soit compris entre 0,25 et 4 ou encore 20/80 et 80/20.- The microparticles of mineral pigments are suspended in a hydroalcoholic solution. The suspension is maintained by stirring. The water: alcohol mixture can vary within wide proportions such that the water: alcohol ratio is between 0.25 and 4 or even 20/80 and 80/20.
L'alcool peut être un mono ou polyalcool saturé ou insaturé bien qu'il soit souhaitable que l'alcool choisi soit parmi les moins réactifs vis-à-vis de l'anhydride organique afin d'éviter toute réaction parasite.The alcohol may be a saturated or unsaturated mono or polyalcohol, although it is desirable that the alcohol chosen is among the least reactive with respect to the organic anhydride in order to avoid any parasitic reaction.
Il devra également de préférence être volatil pour faciliter son élimination subséquente.It should also preferably be volatile to facilitate its subsequent elimination.
De préférence, on choisit les alcools secondaires du type isopropanol ou isobutanol.Preferably, secondary alcohols of the isopropanol or isobutanol type are chosen.
De préférence, on réalise en premier lieu la suspension sous agitation de particules pigmentaires dans la phase hydroalcoolique en laissant la suspension en l'état un temps suffisant pour permettre le débullage puis on y rajoute la solution de chitosane ou dérivés de chitosane salifiés.Preferably, the suspension is first carried out with agitation of pigmentary particles in the hydroalcoholic phase, leaving the suspension in the state sufficient time to allow the boiling then the chitosan solution or salified chitosan derivatives are added thereto.
Le pH de la solution de chitosane salifié ou dérivés de chitosane salifiés est généralement compris entre 2 et 6 selon la forme salifiée choisie. Dans le cas de l'acétate de chitosane ou acétate de dérivés de chitosane, le pH est généralement entre 4 et 4,5.The pH of the solution of salified chitosan or derivatives of salified chitosan is generally between 2 and 6 depending on the salified form chosen. In the case of chitosan acetate or acetate of chitosan derivatives, the pH is generally between 4 and 4.5.
De préférence, la concentration de chitosane ou dérivés de chitosane salifiés est comprise entre 0,005 et 0,5 g/1, avantageusement entre 0,01 et 0,1 g/l. La solution est laissée sous agitation un temps suffisant à l'adsorptioπ ou à l'encrage initial des chaînes de chitosane ou dérivés de chitosane à la surface des pigments et dans le cas de pigments enrobés de mica titane à la fixation de chitosane au titane soit par chelation, soit par complexation. La réaction d'acétylation est effectuée par ajout d'une solution d'un anhydride d'acide organique dans un alcool.Preferably, the concentration of chitosan or salified chitosan derivatives is between 0.005 and 0.5 g / l, advantageously between 0.01 and 0.1 g / l. The solution is left under stirring for a sufficient time for adsorption or for the initial inking of the chitosan chains or chitosan derivatives on the surface of the pigments and in the case of pigments coated with titanium mica to the fixing of chitosan to titanium either by chelation, or by complexation. The acetylation reaction is carried out by adding a solution of an organic acid anhydride in an alcohol.
Comme précédemment, l'alcool sera de préférence un alcool secondaire tel que l'isopropanol ou l'isobutanol.As before, the alcohol will preferably be a secondary alcohol such as isopropanol or isobutanol.
Parmi les anhydrides d'acide organique on choisit de préférence l'anhydride acétique.Among the organic acid anhydrides, acetic anhydride is preferably chosen.
La concentration d'anhydride d'acide organique notamment d'anhydride acétique est comprise entre 0,1 et 10 g/l, de préférence entre 0,5 et 5 g/l.The concentration of organic acid anhydride, in particular acetic anhydride, is between 0.1 and 10 g / l, preferably between 0.5 and 5 g / l.
Selon une variante préférée, on donne ci-après la quantité des différents réactifs mis en jeu, étant entendu que cette variante n'est donnée qu'à titre indicatif et ne saurait en aucune manière limiter le procédé selon l'invention. de à de préférenceAccording to a preferred variant, the quantity of the different reagents involved is given below, it being understood that this variant is given only for information and cannot in any way limit the method according to the invention. from to preferably
Eau 20 80 50 g Alcool (isopropanol) 80 20 50 gWater 20 80 50 g Alcohol (isopropanol) 80 20 50 g
Acétate de chitosane 0,005 0,5 0,04 gChitosan acetate 0.005 0.5 0.04 g
Pigments 0,4 40 4 gPigments 0.4 40 4 g
Anhydride acétique 0,1 10 1 g L'invention concerne également un procédé de préparation tel que décrit ci-dessus, caractérisé en ce que l'étape a) est effectuée en présence d'un ou plusieurs composés d'intérêt organiques tels qu'une molécule active, ce qui permettra une libération contrôlée de cette molécule (effet retard) lorsque les microcapsules de pigments minéraux obtenues auront été incluses dans un milieu approprié.Acetic anhydride 0.1 10 1 g The invention also relates to a preparation process as described above, characterized in that step a) is carried out in the presence of one or more compounds of organic interest such as an active molecule, which will allow a controlled release of this molecule (delay effect) when the microcapsules of mineral pigments obtained have been included in an appropriate medium.
Parmi les molécules actives, on peut citer les molécules pharmaceutiques, les molécules phytosanitaires, divers acides gras saturés ou insaturés ramifiés ou non tels que l'acide octylcarboxylique. De préférence, ces molécules sont incluses dans la paroi de chitine en faible quantité afin de ne pas interférer avec la cohésion du film de chitine.Among the active molecules, mention may be made of pharmaceutical molecules, phytosanitary molecules, various saturated or unsaturated fatty acids, branched or not, such as octylcarboxylic acid. Preferably, these molecules are included in the chitin wall in small quantities so as not to interfere with the cohesion of the chitin film.
L'invention concerne également de nouvelles microparticules de pigments minéraux caractérisées en ce qu'elles sont enrobées d'une couche de chitine ou dérivés de chitine, ladite couche comprenant éventuellement une ou plusieurs substances organiques. Lesdites microparticules enrobées sont susceptibles d'être obtenues par le procédé selon l'invention.The invention also relates to new microparticles of mineral pigments characterized in that they are coated with a layer of chitin or derivatives of chitin, said layer possibly comprising one or more organic substances. Said coated microparticles are capable of being obtained by the method according to the invention.
Ces microparticules enrobées présentent une granulométrie qui dépend bien entendu de la granulométrie des microparticules des pigments minéraux mises en suspension.These coated microparticles have a particle size which of course depends on the particle size of the microparticles of the suspended mineral pigments.
Les microparticules enrobées selon l'invention présentent des propriétés filmogènes de surface. De ce fait, les particules peuvent former d'une part des films à sec sans apporter de caractère viscosant à la solution de mise en oeuvre. D'autre part, les pigments peuvent servir de squelette de maintien à toute formulation et permettre son moulage dans les formes les plus diverses (granulation).The coated microparticles according to the invention have surface film-forming properties. Therefore, the particles can form on the one hand dry films without providing viscosity to the processing solution. On the other hand, the pigments can serve as a support skeleton for any formulation and allow it to be molded in the most diverse forms (granulation).
Les microparticules selon l'invention présentent donc l'intérêt de pouvoir être utilisées d'une façon extrêmement large, notamment en tant que substance filmogène ou pour la granulation de produits tels que les produits toxiques ou les bactéries.The microparticles according to the invention therefore have the advantage of being able to be used in an extremely wide manner, in particular as a film-forming substance or for the granulation of products such as toxic products or bacteria.
Elles peuvent également être utilisées à titre de vecteur pour effet retard lorsque la couche de chitine comprend des molécules organiques par exemple pharmaceutiques, phytosanitaires, cosmétiques, etc. Parmi les applications filmogène, on cite : l'enrobage de semences, l'enrobage de galets ou de comprimés, par exemple des comprimés rendus effervescents, l'utilisation des microparticules dans diverses formulations d'encre d'imprimerie, notamment en procédé OFFSET, en héliographie ou en flexographie.They can also be used as a vector for delay effect when the chitin layer comprises organic molecules, for example pharmaceutical, phytosanitary, cosmetic, etc. Among the film-forming applications, the following are cited: the coating of seeds, the coating of pebbles or tablets, for example tablets made effervescent, the use of microparticles in various printing ink formulations, in particular in the OFFSET process, in heliography or flexography.
Comme autre application filmogène, on cite l'utilisation de ces microparticules dans les formulations de peintures, notamment vinyliques, acryliques, mais également glycérophtaliques. L'ajout de telles microparticules conduit à des dépôts de film à effet couvrant accru. L'une des caractéristiques particulièrement remarquables et inattendues de la présente invention réside donc dans le fait que ces microparticules enrobées permettent l'obtention de nouvelles formes compactées ou agrégées à délitement rapide. Ces formes compactées présentent une densité très inférieure à 1 , notamment de l'ordre de 0,2 environ et peuvent se présenter sous forme de galets. Elles peuvent contenir une charge importante en substance active notamment des substances phytosanitaires, comme l'imidachlopride.As another film-forming application, mention is made of the use of these microparticles in paint formulations, in particular vinyl, acrylic, but also glycerophthalic. The addition of such microparticles leads to film deposits with increased covering effect. One of the particularly remarkable and unexpected characteristics of the present invention therefore lies in the fact that these coated microparticles make it possible to obtain new compacted or aggregated forms with rapid disintegration. These compacted forms have a density much less than 1, in particular of the order of about 0.2 and can be in the form of rollers. They can contain a significant charge of active substance, in particular phytosanitary substances, such as imidachloprid.
Le matériau décrit sous le terme de « compact » est issu de la concression de pigments enrobés de chitine, uniquement liées entre eux par liaisons hydrogénées. Ces liaisons ou pontages se font entre les films de chitine recouvrant et enrobant les surfaces des pigments lamellaires mica titane.The material described under the term of “compact” comes from the compression of pigments coated with chitin, only linked together by hydrogenated bonds. These bonds or bridges are made between the chitin films covering and coating the surfaces of the titanium mica lamellar pigments.
Cette structure lamellaire confère au matériau un comportement spongieux non élastique, à maille aérées dont les interstices forment des cavités d'un volume total voisin de 90 % du matériau et qui sont aptes à être comblées par toutes autres molécules ou formulation de molécules inclusent lors du processus de formation. Les compacts peuvent être obtenus à partir de pigments enrobés de chitine ou de ces dérivés tels que déjà décrits. L'enrobage peut être de 0,1 à 10 % de chitine mais préférentiellement de 0,3 à 3 %. Les caractéristiques des compacts obtenus pour ces concentrations sont voisines et décrites dans le tableau suivant. This lamellar structure gives the material a non-elastic, spongy, airy mesh behavior, the interstices of which form cavities with a total volume close to 90% of the material and which are capable of being filled with any other molecules or formulation of molecules included during the training process. The compacts can be obtained from pigments coated with chitin or these derivatives as already described. The coating can be from 0.1 to 10% of chitin but preferably from 0.3 to 3%. The characteristics of the compacts obtained for these concentrations are similar and described in the following table.
Ces microparticules peuvent donc être utilisées dans le compactage. Une technique de compactage consiste à hydrater les microparticules de pigments enrobées par une quantité d'eau inférieure à la quantité nécessaire à leur remise en suspension liquide. Cette quantité est de l'ordre de deux fois le poids des microparticules de pigments enrobés secs. Ce système lors du séchage s'agrège sans variations importantes de volume. Si l'on apporte d'autres composés dans la phase aqueuse, ceux-ci sont emprisonnés au séchage dans la structure du réseau tridimensionnel des pigments nacrés.These microparticles can therefore be used in compaction. A compacting technique consists in hydrating the microparticles of coated pigments with an amount of water less than the amount necessary for their resuspension in liquid. This amount is of the order of twice the weight of the microparticles of dry coated pigments. This system during drying aggregates without significant variations in volume. If other compounds are added to the aqueous phase, these are trapped during drying in the structure of the three-dimensional network of pearlescent pigments.
Les microparticules de pigments minéraux selon l'invention peuvent également être utilisées dans la granulation de différents produits sous forme agrégée ou compactée : les produits toxiques mélangés avec les microparticules selon l'invention, après séchage, forment un galet qui limite l'effet toxique du produit de traitement pulvérulent. Ce galet est ensuite utilisable par simple mélange à l'eau ou il se délite sans viscoser le milieu.The microparticles of mineral pigments according to the invention can also be used in the granulation of various products in aggregated or compacted form: the toxic products mixed with the microparticles according to the invention, after drying, form a pebble which limits the toxic effect of powdery treatment product. This roller can then be used by simple mixing with water or it disintegrates without viscosing the medium.
La granulation de bactéries dans des microparticules selon l'invention est également une solution aisée aux difficultés qui sont généralement rencontrées dans l'utilisation de systèmes bactériens dans les applications biotechnologiques. On connaît en effet les difficultés de conservation des souches dans leur transport et dans leur mise en oeuvre.The granulation of bacteria in microparticles according to the invention is also an easy solution to the difficulties which are generally encountered in the use of bacterial systems in biotechnological applications. We know indeed the difficulties of conservation of the strains in their transport and in their implementation.
Les microparticules selon l'invention dont la couche de chitine comprend une ou plusieurs substances actives peuvent être libérées de façon contrôlée. Les facteurs de libération sont généralement l'humidité du milieu, le pH, la biodégradation du système. D'autres utilisations peuvent également être envisagées telles que le compactage des colorants, des pigments ou encore des parfums.The microparticles according to the invention in which the chitin layer comprises one or more active substances can be released in a controlled manner. The release factors are generally the humidity of the medium, the pH, the biodegradation of the system. Other uses can also be envisaged such as the compacting of dyes, pigments or even perfumes.
Notamment le toucher agréable des microparticules selon l'invention permet leur usage dans la formulation à sec des industries cosmétiques (fond de teint).In particular, the pleasant touch of the microparticles according to the invention allows their use in the dry formulation of the cosmetic industries (foundation).
Les exemples ci-dessous illustrent l'invention à titre non limitatif. Exemple 1 Enrobage de pigments nacrés Iriodine® 221The examples below illustrate the invention without implied limitation. EXAMPLE 1 Coating of Iriodine® 221 Pearlescent Pigments
• Préparation initiale Dans un réacteur de 30 litres, on verse successivement :• Initial preparation In a 30 liter reactor, successively:
1 kg de pigments Iriodine® 221 de granulométrie comprise entre 5 et 25 μm1 kg of Iriodine® 221 pigments with a particle size between 5 and 25 μm
8 litres d'isopropanol 12 litres d'eau Le mélange est agité durant deux heures afin de débuller les solutions.8 liters of isopropanol 12 liters of water The mixture is stirred for two hours in order to boil the solutions.
• Phase de fixation du chitosane• Chitosan fixing phase
Sur la solution précédente en agitation, on verse : une solution préalablement filtrée de 5 litres d'eau contenant 30 g de chitosane (0,6 %, 0,18 moles) et 15 g d'acide acétique.On the previous solution with stirring, pour: a previously filtered solution of 5 liters of water containing 30 g of chitosan (0.6%, 0.18 moles) and 15 g of acetic acid.
Le mélange est agité durant deux heures pour une adsorption maximale du chitosane sur les pigments.The mixture is stirred for two hours for maximum adsorption of the chitosan on the pigments.
• Phase de réacétylation• Reacetylation phase
Sur la solution précédente en agitation, on verse : 500 ml d'une solution fraîchement préparée mais homogène, de propylène glycol (monopropylène glycol) contenant 100 g (une mole) d'anhydride acétique. Dans ces conditions, l'acétylation est effectuée pour des températures comprises entre 15 et 25°C, les pigments enrobés dephasent avec perte de flux dans les 5 à 45 min qui suivent le rajout de la solution de réacétylation. L'agitation est maintenue durant 2 heures, puis, après décantation et egouttage par toute méthode appropriée, les pigments sont séchés et conditionnés.On the previous solution with stirring, pour: 500 ml of a freshly prepared but homogeneous solution of propylene glycol (monopropylene glycol) containing 100 g (one mole) of acetic anhydride. Under these conditions, the acetylation is carried out for temperatures between 15 and 25 ° C., the coated pigments phase shift with loss of flux within 5 to 45 min following the addition of the reacetylation solution. Stirring is continued for 2 hours, then, after decanting and draining by any suitable method, the pigments are dried and conditioned.
Exemple 2 Enrobage de pigments nacrés Iriodine® 111 (granulométrie 1 à 15 μm)Example 2 Coating of Iriodine® 111 pearlescent pigments (particle size 1 to 15 μm)
Les conditions opératoires de l'exemple 1 sont reproduites et conduisent aux pigments correspondants. Exemple d'application A - Applications filmogènes • Enrobage de semencesThe operating conditions of Example 1 are reproduced and lead to the corresponding pigments. Application example A - Film-forming applications • Seed coating
Une solution de pelliculage de maïs est réalisée par mélange de 30 parties en poids de pigments de l'exemple 1 préalablement enrobés par 1 % de chitine, 60 parties de produits phytosanitaires classiques et 90 parties d'eau afin d'assurer le mouillage. Cette solution communément appelée bouillie est agitée en présence de maïs ou pulvérisée sur celui-ci à raison de 2 kg par 100 kg de maïs. L'absorption de l'eau par les graines de maïs provoque le dépôt de la bouillie qui se dépose à la surface de la graine. Le maintien filmogène de la formule est assurée par les pigments enrobés.A corn coating solution is produced by mixing 30 parts by weight of pigments from Example 1 previously coated with 1% chitin, 60 parts of conventional plant protection products and 90 parts of water to ensure wetting. This solution commonly called porridge is stirred in the presence of corn or sprayed on it at the rate of 2 kg per 100 kg of corn. The absorption of water by corn seeds causes the deposition of porridge which is deposited on the surface of the seed. The film-forming maintenance of the formula is ensured by the coated pigments.
• Galets de bains• Bath pebbles
Une part de pigments enrobés, préalablement hydratés, à 20 % est saupoudrée sur 100 parties d'une composition ayant la forme de galets ou de comprimés rendus effervescents dans l'eau par leur émission de CO2. Les pigments enrobés se déposent pour former à la surface des comprimés un film protecteur.A part of coated pigments, hydrated beforehand, at 20% is sprinkled on 100 parts of a composition having the form of pebbles or tablets made effervescent in water by their emission of CO 2 . The coated pigments are deposited to form a protective film on the surface of the tablets.
• Encre d'imprimerie• Printing ink
Une composition de 10 à 60 parties pour 100 g de pigments enrobés, de préférence 30 parties, est ajoutée dans diverses formulations d'encre d'imprimerie. Ces formules sont utilisables en procédés OFFSET, en héliographie et en flexographie. • PeintureA composition of 10 to 60 parts per 100 g of coated pigments, preferably 30 parts, is added in various formulations of printing ink. These formulas can be used in OFFSET processes, heliography and flexography. • Painting
Une préparation à 30 parties de pigments dans une formulation de peinture conduit en solvant vinylique, acrylique mais également en milieu glycérophaté à des dépôts de film à effet couvrant accru.A preparation with 30 parts of pigments in a paint formulation leads in vinyl solvent, acrylic but also in glycerophatic medium to film deposits with increased covering effect.
• Compactage• Compaction
La technique de compactage consiste à hydrater les pigments enrobés par une quantité d'eau inférieure à la quantité nécessaire à leur remise en suspension liquide. Cette quantité est de l'ordre de deux fois le poids des microparticules de pigments enrobés secs. Ce système lors du séchage s'agrège sans variations importantes de volume. Si l'on apporte d'autres composés dans la phase aqueuse, ceux-ci sont emprisonnés au séchage dans la structure du réseau tridimensionnel des pigments nacrés.The compacting technique consists in hydrating the coated pigments with an amount of water less than the amount necessary for their resuspension in liquid. This amount is of the order of twice the weight of the microparticles of dry coated pigments. This system during drying aggregates without significant variations in volume. If other compounds are added to the aqueous phase, these are trapped during drying in the structure of the three-dimensional network of pearlescent pigments.
B - GranulationB - Granulation
Produits toxiquesToxic products
50 g de florapearl 12® enrobés sont mélangés à 50 de produit phytosanitaire. Le tout séché forme un galet qui limite l'effet toxique pulvérulent du produit de traitement. Ce galet est ensuite utilisable par simple mélange à l'eau où il se délite sans viscoser le milieu.50 g of coated florapearl 12® are mixed with 50 of phytosanitary product. The dried whole forms a pebble which limits the powdery toxic effect of the treatment product. This roller can then be used by simple mixing with water where it disintegrates without viscosing the medium.
Le Florapearl 12® est l'Iriodine®, micatitane référence Iriodine® 120, baptisé Florapearl® pour son application dans les semences.Florapearl 12® is Iriodine®, micatitane reference Iriodine® 120, called Florapearl® for its application in seeds.
Bactéries Une culture de Rhizobium est préalablement réalisée. Elle est directement mélangée en égale proportion à des pigments enrobés préalablement stérilisés par irradiation. Après séchage par méthode appropriée, dans des moules, les galets obtenus sont conservés en environnement stérile puis testés pour leur aptitude à provoquer des nodulations au bout de 1 , 2, 6, 9, 12 mois et comparés avec succès à des témoins fixés sur divers autres supports. Une culture d'Azospirillium et une culture de Speudomonas ont pu être conservées par les mêmes méthodes pour favoriser la lutte biologique. Leur application est faite en granulés au pourtour direct des plants traités.Bacteria A culture of Rhizobium is carried out beforehand. It is directly mixed in equal proportion with coated pigments previously sterilized by irradiation. After drying by an appropriate method, in molds, the rollers obtained are kept in a sterile environment and then tested for their ability to cause nodulations after 1, 2, 6, 9, 12 months and successfully compared with controls fixed on various other media. A culture of Azospirillium and a culture of Speudomonas could be preserved by the same methods to promote biological control. Their application is made in granules at the direct periphery of the treated plants.
Vecteur pour effet retard et fixationVector for delay and fixation effect
Les microparticules de pigments peuvent être enrobées par une teneur plus ou moins élevée en chitine. De cette quantité va dépendre un certain nombre de paramètres. En particulier, si lors de l'enrobage ou lors du compactage on emprisonne dans la chitine naissante ou dans les granulés en formation, une molécule active comportant des sites de fixation sensibles aux liaisons hydrogène tels que la plupart des molécules organiques classiques, leur libération dans le temps peut être maîtrisée. Les facteurs de libération seront alors l'humidité du milieu, le pH, la biodégradation du système. Cette technique a été utilisée sur divers acides gras saturés ou insaturés ramifiés ou non. Entre autres exemples, l'acide octylcarboxylique piégé à 1 % dans un galet de 5 cm de diamètre sur 1 cm d'épaisseur et maintenu sous eau courante, relargue totalement (perte de signal spectrographique) en trois semaines. D'autres exemples peuvent être apportés. Le compactage peut servir à maintenir des colorants, des pigments ou encore des parfums. Son toucher agréable permet son usage dans la formulation à sec des industries cosmétiques (fond de teint, etc .).The pigment microparticles can be coated with a more or less high content of chitin. A number of parameters will depend on this quantity. In particular, if during coating or during compaction, an active molecule comprising binding sites sensitive to hydrogen bonds such as most conventional organic molecules is trapped in the nascent chitin or in the granules in formation, their release in time can be mastered. The release factors will then be the humidity of the medium, the pH, the biodegradation of the system. This technique has been used on various saturated or unsaturated fatty acids, branched or not. Among other examples, octylcarboxylic acid trapped at 1% in a pebble 5 cm in diameter and 1 cm thick and kept under running water, completely releases (loss of spectrographic signal) in three weeks. Other examples can be given. Compaction can be used to maintain dyes, pigments or even perfumes. Its pleasant touch allows it to be used in the dry formulation of the cosmetic industries (foundation, etc.).
La figure unique annexée est une photographie de microscopie optique d'un pigment mica oxyde de titane enrobé de chitine (longueur du pigment environ 50 μrη). The attached single figure is a microscopic photograph of a titanium oxide mica pigment coated with chitin (length of the pigment approximately 50 μrη).

Claims

REVENDICATIONS 1. Microparticules de pigments minéraux, caractérisées en ce qu'elles sont enrobées d'une couche de chitine ou dérivés de chitine comprenant éventuellement une ou plusieurs substances organiques.  CLAIMS 1. Microparticles of mineral pigments, characterized in that they are coated with a layer of chitin or derivatives of chitin possibly comprising one or more organic substances.
2. Microparticules de pigments minéraux selon la revendication 1 , caractérisées en ce que lesdites microparticules de pigments minéraux non enrobées présentent une granulométrie moyenne comprise entre 1 et 200 μm, de préférence supérieure à 5 μm2. Microparticles of mineral pigments according to claim 1, characterized in that said microparticles of uncoated mineral pigments have an average particle size between 1 and 200 μm, preferably greater than 5 μm
3. Microparticules de pigments minéraux selon la revendication 1 , caractérisées en ce que lesdites microparticules de pigments minéraux non enrobées sont choisies dans le groupe constitué par les oxydes métalliques et le mica-titane3. Microparticles of mineral pigments according to claim 1, characterized in that said microparticles of uncoated mineral pigments are chosen from the group consisting of metal oxides and mica-titanium
4. Forme agrégée ou compactée de microparticules selon l'une des revendications 1 à 3, à délitement rapide, éventuellement chargée en substance active.4. Aggregate or compacted form of microparticles according to one of claims 1 to 3, rapidly disintegrating, possibly loaded with active substance.
5. Forme agrégée ou compactée de microparticules selon la revendication 4, chargée en substance active phytosanitaire.5. Aggregate or compacted form of microparticles according to claim 4, loaded with phytosanitary active substance.
6. Procédé de préparation de microparticules de pigments minéraux enrobées d'une couche de chitine ou de dérivés de chitine selon l'une des revendications 1 à 3, caractérisé en ce que: a) des microparticules de pigments minéraux en suspension sont mises en contact avec une solution de chitosane ou dérivés de chitosane salifiés de façon à provoquer la coacervation du chitosane ou dérivés de chitosane autour des microparticules de pigments, b) les microparticules enrobées sont ensuite soumises à une réaction d'acétylation au moyen d'anhydride d'acide organique.6. Process for the preparation of microparticles of mineral pigments coated with a layer of chitin or of chitin derivatives according to one of claims 1 to 3, characterized in that: a) microparticles of mineral pigments in suspension are brought into contact with a solution of chitosan or chitosan derivatives salified so as to cause the coacervation of chitosan or chitosan derivatives around the pigment microparticles, b) the coated microparticles are then subjected to an acetylation reaction using acid anhydride organic.
7. Microparticules de pigments minéraux, caractérisées en ce qu'elles sont enrobées d'une couche de chitine ou dérivés de chitine comprenant éventuellement une ou plusieurs substances organiques et en ce qu'elles sont susceptibles d'être obtenues par le procédé selon la revendication 6.7. Microparticles of mineral pigments, characterized in that they are coated with a layer of chitin or chitin derivatives optionally comprising one or more organic substances and in that they are capable of being obtained by the process according to claim 6.
8. Utilisation des microparticules selon l'une des revendications 1 à 3 ou la revendication 7 comme substance filmogène. 8. Use of the microparticles according to one of claims 1 to 3 or claim 7 as a film-forming substance.
9. Utilisation selon la revendication 8, caractérisée en ce que les microparticules sont utilisées pour l'enrobage des semences, des galets de bains, dans les encres d'imprimerie, les peintures, le compactage.9. Use according to claim 8, characterized in that the microparticles are used for coating seeds, bath rollers, in printing inks, paints, compacting.
10. Utilisation des microparticules selon l'une des revendications 1 à 3 ou la revendication 7, pour la granulation de produits toxiques, des bactéries. 10. Use of the microparticles according to one of claims 1 to 3 or claim 7, for the granulation of toxic products, bacteria.
EP97947106A 1996-11-21 1997-11-20 Mineral pigment microparticles covered with a chitin layer Withdrawn EP0885265A1 (en)

Applications Claiming Priority (3)

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FR9614216 1996-11-21
FR9614216A FR2755972B1 (en) 1996-11-21 1996-11-21 PROCESS FOR THE PREPARATION OF MICROPARTICLES OF MINERAL PIGMENTS COATED WITH A CHAIN LAYER, MICROPARTICLES OBTAINED AND USE OF SUCH MICROPARTICLES
PCT/FR1997/002096 WO1998022540A1 (en) 1996-11-21 1997-11-20 Mineral pigment microparticles covered with a chitin layer

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DE19962348A1 (en) * 1999-12-23 2001-07-05 Henkel Kgaa Pigmented chitosan capsules
DE19962350A1 (en) * 1999-12-23 2001-06-28 Henkel Kgaa Colored chitosan capsules containing an aqueous lipid emulsion, useful in compositions for body and hair care and cleansing, have a wall comprising a chitosan-dye complex
DE10140246A1 (en) 2001-08-09 2003-03-06 Forsch Pigmente Und Lacke E V Process for treating surfaces of substrates
DE10140247A1 (en) * 2001-08-09 2003-03-06 Forsch Pigmente Und Lacke E V Process for coating substrate surfaces
US20070207927A1 (en) * 2006-03-01 2007-09-06 Rosa Fred C Polymer based seed coating
EP3653674A1 (en) * 2018-11-15 2020-05-20 Commissariat à l'Énergie Atomique et aux Énergies Alternatives Process for manufacturing omniphobic cosmetic pigments

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JPS62223108A (en) * 1986-03-25 1987-10-01 Daito Kasei Kogyo Kk Cosmetic pigment coated with chitosan and production thereof
JPS6327501A (en) * 1986-07-22 1988-02-05 Fuji Boseki Kk Chitin or chitosan minute particle containing ultrafine powder of inorganic substance
JP2524287B2 (en) * 1992-07-23 1996-08-14 富士紡績株式会社 Method for regenerating microorganism-immobilized carrier

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