WO2015140764A1 - Particles of melamine-urea-formaldehyde (muf) containing a polymer with a tg less than 75 °c. - Google Patents

Particles of melamine-urea-formaldehyde (muf) containing a polymer with a tg less than 75 °c. Download PDF

Info

Publication number
WO2015140764A1
WO2015140764A1 PCT/IB2015/052049 IB2015052049W WO2015140764A1 WO 2015140764 A1 WO2015140764 A1 WO 2015140764A1 IB 2015052049 W IB2015052049 W IB 2015052049W WO 2015140764 A1 WO2015140764 A1 WO 2015140764A1
Authority
WO
WIPO (PCT)
Prior art keywords
polymer
particles
particle
core
melamine
Prior art date
Application number
PCT/IB2015/052049
Other languages
French (fr)
Inventor
Aurélien AUGER
Jonathan SKRZYPSKI
Original Assignee
Commissariat A L'energie Atomique Et Aux Energies Alternatives
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 Commissariat A L'energie Atomique Et Aux Energies Alternatives filed Critical Commissariat A L'energie Atomique Et Aux Energies Alternatives
Publication of WO2015140764A1 publication Critical patent/WO2015140764A1/en

Links

Classifications

    • 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
    • B01J13/06—Making microcapsules or microballoons by phase separation
    • B01J13/14—Polymerisation; cross-linking
    • B01J13/18—In situ polymerisation with all reactants being present in the same phase
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B1/00—Dyes with anthracene nucleus not condensed with any other ring
    • C09B1/16—Amino-anthraquinones
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B11/00—Diaryl- or thriarylmethane dyes
    • C09B11/04—Diaryl- or thriarylmethane dyes derived from triarylmethanes, i.e. central C-atom is substituted by amino, cyano, alkyl
    • C09B11/06—Hydroxy derivatives of triarylmethanes in which at least one OH group is bound to an aryl nucleus and their ethers or esters
    • C09B11/08—Phthaleins; Phenolphthaleins; Fluorescein
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B11/00—Diaryl- or thriarylmethane dyes
    • C09B11/04—Diaryl- or thriarylmethane dyes derived from triarylmethanes, i.e. central C-atom is substituted by amino, cyano, alkyl
    • C09B11/10—Amino derivatives of triarylmethanes
    • C09B11/24—Phthaleins containing amino groups ; Phthalanes; Fluoranes; Phthalides; Rhodamine dyes; Phthaleins having heterocyclic aryl rings; Lactone or lactame forms of triarylmethane dyes
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B29/00—Monoazo dyes prepared by diazotising and coupling
    • C09B29/06—Monoazo dyes prepared by diazotising and coupling from coupling components containing amino as the only directing group
    • C09B29/08—Amino benzenes
    • C09B29/0805—Amino benzenes free of acid groups
    • C09B29/0807—Amino benzenes free of acid groups characterised by the amino group
    • C09B29/0809—Amino benzenes free of acid groups characterised by the amino group substituted amino group
    • C09B29/0811—Amino benzenes free of acid groups characterised by the amino group substituted amino group further substituted alkylamino, alkenylamino, alkynylamino, cycloalkylamino aralkylamino or arylamino
    • C09B29/0813—Amino benzenes free of acid groups characterised by the amino group substituted amino group further substituted alkylamino, alkenylamino, alkynylamino, cycloalkylamino aralkylamino or arylamino substituted by OH, O-C(=X)-R, O-C(=X)-X-R, O-R (X being O,S,NR; R being hydrocarbonyl)
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09B—ORGANIC DYES OR CLOSELY-RELATED COMPOUNDS FOR PRODUCING DYES, e.g. PIGMENTS; MORDANTS; LAKES
    • C09B67/00—Influencing 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
    • C09B67/0097—Dye preparations of special physical nature; Tablets, films, extrusion, microcapsules, sheets, pads, bags with dyes

Definitions

  • the present invention relates to the field of heart-shell type particles used to convey at least one molecule of interest, in particular a marking material.
  • Marking is an important tool in the context of trademark protection, product traceability and the fight against counterfeiting, for example for the paper, perfume, pharmacy or spirits industries.
  • marking materials are coloring molecules, luminescent and / or conductive molecules. This ideally unfalsifiable marking is very often visually characterizable at a given wavelength.
  • optical markers such as fluorescent molecules, for example, which are invisible to the naked eye but which, on the other hand, reveal themselves in response to UV exposure.
  • these molecules are immobilized at the level of a support in a form associated with an ancillary material which has a vehicle function for them and allows them to be immobilized in a permanent manner at the level of the support. This material also makes it possible to protect them during storage and makes them compatible with use in a wide variety of media.
  • this ancillary material carrying the marker may be introduced into an ink, paint or varnish which is then deposited on the surface of the support to be treated.
  • the document US Pat. No. 6,863,923 describes a printing paste based on a pre-condensate based on polyorganosiloxanes obtained by a sol-gel process and constituting a matrix in which is included at least one coloring, luminescent, conductive element. and / or catalytic.
  • This paste may be applied to a support in the form or pattern desired and densified by heat treatment, at a temperature below the glass transition temperature of the matrix thus formed.
  • the densification temperature to be applied in this process is of the order of 4000 ° C., which constitutes a serious limitation from the point of view of the useful molecules of interest, for example of usable chromophores.
  • hydrophilic polymers that can be used as inks for security and anti-fraud applications, and in which fluoresor proteins of proteorhodopsin are integrated.
  • the manufacture and preservation of these inks require low temperatures, of the order of 4 ° C, hardly compatible with industrial applications.
  • the present invention aims precisely to meet these needs.
  • the subject of the present invention is particles having a core formed wholly or partly of at least one polymer having a glass transition temperature below 75 ° C., encapsulated in a shell formed from minus a melamine-urea-formaldehyde polymer.
  • the inventors have indeed found that the core-shell architecture particles in accordance with the invention are particularly advantageous for conveying in their core molecules of interest, in particular a marking material and in particular a optical marker.
  • an optical marker is a molecule which, under the action of a stimulus, for example a change in pH, a change in temperature, or a UV or IR spectral exposure, generates a new chromatic effect, for example a color change or a luminescent effect, of a definite duration.
  • This optical marker may especially be chosen from organic or inorganic coloring agents, phosphors, fluorophores, thermochromic and photochromic.
  • the subject of the invention is also a method for preparing particles according to the invention comprising at least the steps consisting in:
  • the method according to the invention has the advantage of being easy to implement, and makes it possible to obtain particles of well-defined and homogeneous size.
  • the method advantageously allows the growth of MUF forming the shell around said polymer having a glass transition temperature of less than 75 ° C.
  • the organic phase contains at least one polymer having a glass transition temperature of less than 50 ° C.
  • the heat treatment of step (iv) consists of heating at a temperature of between 28 ° C. and 100 ° C., preferably between 50 ° C. and 99 ° C.
  • the method further comprises a dialysis step (vi).
  • the invention also relates to a method for charging a molecule of interest in the heart of a particle according to the invention, characterized in that it comprises the impregnation of said particle in a supercritical C0 2 medium containing one or more molecules (s). ) of interest.
  • the particles have a core-shell structure in which the melamine-urea-formaldehyde (MUF) shell contains at least one polymer having a glass transition temperature of less than 75 ° C, preferably less than 50 ° C.
  • MAF melamine-urea-formaldehyde
  • the particles according to the invention are water-dispersible.
  • the particles according to the invention may be of nano or micrometric size and / or advantageously have an average size of between 50 nm and 200 ⁇ .
  • the present invention relates to a particle having a core formed wholly or partly of at least one polymer having a glass transition temperature below 75 ° C, encapsulated in a shell formed of at least one melamine polymer -urea-formaldehyde, said particle having an average size of between 50 nm and 200 ⁇ .
  • the average particle size is between 1 ⁇ and 20 ⁇ .
  • the particle size is preferably between 50 nm and 200 nm.
  • This size can be determined by scanning electron microscopy.
  • the size of the factors of the invention may in particular be adjusted by the parameters chosen for the polymerization. A prolonged duration of the polymerization will result in increasing the size of the particles.
  • the particles according to the invention are non-porous.
  • the polymer having a glass transition temperature below 75 ° C. and the MUF are combined in a polymer / MUF weight ratio varying from 1% to 10%.
  • Melamine-urea-formaldehyde is a thermosetting polymer belonging to the family of aminoplasts, polymers that are widely used and widely used in many fields such as in the wood industry as adhesives, in the manufacture of materials electric or kitchen utensils as coating including food grade, in the manufacture of varnish, paint ...
  • the melamine-urea-formaldehyde polymer is formed by a polymerization or condensation reaction between melamine (M), urea (U) and formaldehyde (F), around heart of interest.
  • M melamine
  • U urea
  • F formaldehyde
  • the units (M), (U) and (F) are used in proportions by weight equal to 2.5 / 1 / 8.5.
  • the mechanical properties of the particle are in particular proportional to the proportion of formaldehyde.
  • the MUF particles can in particular be obtained according to the method described by Liu, X. et al (Liu, X, et al., Macromolecular Materials and Engineering, 2009, 294, 389-395).
  • the particle bark may also include silica or organo-silica.
  • silica or organo-silica Their presence in the reaction medium during the polymerization of the monomeric entities dedicated to form the MUF will lead to their incorporation into the bark.
  • the presence of these ancillary materials is particularly advantageous for conferring, if necessary, surface functionalities ancillary to the particles according to the invention via specific coupling agents, such as, for example, trimethoxysilane.
  • the polymer forming all or part of the core of the particles preferably has a glass transition temperature between 30 ° C and 75 ° C, preferably between 30 ° C and 50 ° C.
  • glass transition temperature means the change of state of the polymer or of the polymerized material, under the action of the temperature, causing significant variations in its mechanical properties.
  • Tg glass transition temperature
  • the polymer is said to be vitreous (solid state) and exhibits the behavior of an elastic solid body.
  • the polymer exhibits a behavior of plastic solid (viscoelastic state), following the weakening of intermolecular bonds (Van der Waals force ).
  • the polymers that are suitable according to the invention also prove to be advantageously compatible with an impregnation process in a supercritical medium and more particularly in a supercritical C0 2 medium.
  • the polymer forming the core of the particles according to the present invention may advantageously be chosen from polyethylene glycols, polyvinylpyrrolidones, polyethylmethacrylates, derivatives of polyvinyl alcohols, polystyrenes, latices, polyethylenes, polypropylenes and their mixtures. .
  • the polymer forming the core of the particles is chosen from polyethylene glycol, polyoxyethylene stearate, poly (vinylidene co-vinyl chloride), polyvinylpyrrolidone, poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate), poly ( maleic anhydride-act-1-octadecene), polyvinyl chloride and polyvinyl alcohol derivatives.
  • it is a polyethylene glycol, in particular of molecular weight ranging from 400 gmol 1 to 40000 gmol -1 and in particular about 6000 gmol 4 .
  • Process for preparing the particles is a polyethylene glycol, in particular of molecular weight ranging from 400 gmol 1 to 40000 gmol -1 and in particular about 6000 gmol 4 .
  • the present invention further provides a method of preparing particles comprising the steps of:
  • the present invention further provides a method of preparing particles comprising the following steps:
  • the process according to the invention firstly requires an organic phase containing the polymer (s) having a glass transition temperature below 75 ° C to be encapsulated.
  • organic solvent or mixture of organic solvents is therefore advantageously chosen with regard to the nature of the polymer having a glass transition temperature below 75 ° C., to be treated according to the invention. Moreover, it is also chosen in view of its lack of solubility in an aqueous medium to precisely obtain a corresponding emulsion when it comes into contact with the aqueous phase.
  • the solvent may or may not be volatile and is preferably chosen from dichloromethane, cyclohexane, toluene or heptane.
  • the organic phase may comprise from 1% to 20% by weight of polymer (s) having a glass transition temperature of less than 75 ° C relative to its total weight.
  • the process according to the invention also requires the provision of an aqueous phase.
  • This aqueous phase contains at least melamine (M), urea (U), and formaldehyde (F), as defined above.
  • the aqueous phase may comprise water and optionally further contain a water-soluble polymer.
  • water-soluble polymer in the context of the present invention a liquid compound at room temperature and miscible with water (miscibility in water greater than 50% by weight at 25 ° C and at atmospheric pressure).
  • the water-soluble polymers that can be used in the compositions according to the invention may or may not be volatile.
  • polyvinyl alcohol PVA
  • polyoxazoline polyvinylpyrrolidone
  • PVP polyvinylpyrrolidone
  • gelatin cellulose and hydroxyalkyl cellulose
  • chitosans chitin
  • polyvinyl alcohol makes it possible to obtain particles of micrometric size, because of its ability to stabilize larger particles.
  • the MUF and the polymer (s) having a glass transition temperature below 75 ° C are contacted in controlled amounts so that the particles have a polymeric weight ratio (s). ) / MUF ranging from 1% to 10%.
  • the emulsion is formed in the presence of at least one surfactant.
  • the (s) surfactant (s) is (are) present (s) initially in the aqueous phase.
  • the surfactants that are suitable for the invention may be chosen from any of the classes of surfactants (anionic, cationic, nonionic or amphoteric). More specifically, they may be chosen from surfactants conventionally used in the processes for emulsification of the organic phase under consideration. Thus, to obtain emulsions of organic phase type in water, surfactants having a hydrophilic / lipophilic balance (HLB) greater than 14 are chosen.
  • HLB hydrophilic / lipophilic balance
  • the surfactants that may be used according to the invention are advantageously non-amphoteric and may be more particularly chosen from anionic, cationic and nonionic surfactants.
  • the surfactant (s) are solubilized beforehand in the aqueous phase.
  • the surfactants are used in the process according to the invention in a reduced amount and preferably between 0.1% and 10% by weight, expressed relative to the weight of the aqueous phase.
  • the surfactant is for example selected from sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide, such as the poloxamers sold under the names Pluronic by BASF, and surfactants sold under the designations IGEPAL ® and Triton ® X.
  • SDS sodium dodecyl sulfate
  • cetyltrimethyl ammonium bromide such as the poloxamers sold under the names Pluronic by BASF
  • surfactants sold under the designations IGEPAL ® and Triton ® X surfactants sold under the designations IGEPAL ® and Triton ® X.
  • the surfactant used is sodium dodecyl sulphate (SDS).
  • the two phases, organic and aqueous, are brought together under conditions conducive to the production of a stable emulsion at room temperature, with stirring.
  • the stirring is maintained at a slow rate when adding the polymer (s) having a glass transition temperature below 75 ° C and then increased to obtain a vigorous stirring and produce stable emulsion.
  • the solution containing the polymer (s) having a glass transition temperature below 75 ° C. is introduced slowly into the mixture containing the melamine-formaldehyde prepolymer and the urea, in order to promote the growth. of the MUF forming the shell around the polymer (s).
  • the stirring is maintained at 300 rpm and then increased to 500 rpm to obtain the stable emulsion.
  • This stirring generally mechanical, is prolonged by a sufficient time to obtain the expected emulsion.
  • stirring is maintained for 10 minutes.
  • an emulsion formed of droplets of organic phase dispersed in an aqueous phase, is obtained.
  • the method according to the invention then comprises a step of heating the emulsion, with stirring, for a time sufficient to transform the droplets of ⁇ emulsion in the form of particles.
  • the units M, U, and F polymerize to form the MUF which is organized around the heart of interest to form the expected particles.
  • the heating considered in the process according to the invention can be carried out at a temperature ranging from 28 ° C. to 100 ° C., preferably ranging from 50 ° C. to 99 ° C.
  • the emulsion obtained is heated at 86 ° C. for 180 minutes with continuous stirring at 500 rpm with the addition of 10 ml of water. every 60 minutes to compensate for the amount of water evaporated during heat treatment.
  • the method according to the invention further comprises a step of isolating the particles obtained in the previous step. They can in particular be isolated by tangential or frontal filtration of the liquid medium containing it. The particles of smaller sizes can in particular be isolated by ultrafiltration.
  • the particles are preferably dialyzed for several days.
  • a particular interest of the particles according to the invention is their compatibility with a mode of impregnation of the polymer forming their core in a supercritical CO 2 medium.
  • a process for impregnating a polymer with a supercritical solvent indeed offers the significant advantage of being free from organic solvents, used for traditional impregnation methods and which are likely to pose toxicity problems more or less large scale.
  • the core-shell architecture particles according to the invention lend themselves to this charging phenomenon by impregnation in a supercritical C0 2 medium.
  • Supercritical CO 2 is particularly interesting for adsorption impregnation with regard to its high diffusivity, its high density, and its low viscosity.
  • the material forming the bark of the particles does not prevent impregnation of the polymer, forming the core of the particles, with a molecule of interest in a supercritical CO 2 medium.
  • another object of the present invention relates to a method useful for charging at least one molecule of interest in the heart of a particle according to the invention comprising impregnating said particle in a supercritical CO 2 medium containing one or more molecules ( s) of interest. More specifically, the present invention also provides a process useful for preparing a particle according to the invention loaded into at least one molecule of interest, comprising at least the steps of:
  • said medium C0 2 containing said molecule can be brought into contact with at least one particle according to the invention under a pressure of between 200 bar and 350 bar, preferably between 250 bar and 300 bar.
  • said medium C0 2 containing said molecule is brought into contact with at least one particle according to the invention at a temperature between 70 ° C and 90 ° C, preferably equal to 80 ° C, more particularly for a period of between 45 minutes and 75 minutes, preferably equal to 60 minutes.
  • placing said CO 2 medium containing said molecule with at least one particle according to the invention is carried out in the presence of a co-solvent, for example tetrahydrofuran (THF).
  • a co-solvent for example tetrahydrofuran (THF).
  • the particles considered according to the invention can be further loaded in their core with at least one molecule of interest.
  • These molecules of interest may be any compound having an affinity with the polymer having a glass transition temperature below 75 ° C forming their core.
  • the particles according to the invention are particularly advantageous for transporting hydrophobic molecules.
  • a molecule of interest may be a marking material and preferably an optical marker.
  • the invention therefore also relates to the use of a particle according to the invention and loaded in its core with at least one marking material, as a marking tool.
  • the particles according to the invention have the advantage of not harming the reactivity of the molecule of interest that they carry in their heart. In the case of an optical marker, the latter remains characterizable although located in the heart of said particle.
  • optical markers may especially be chosen from organic or inorganic coloring agents, phosphors or fluorophores, thermochromes, fluorophores, or photochromes.
  • organic or inorganic coloring agents there may be mentioned in particular:
  • azo dyes for example N-ethyl-N- (2-hydroxyethyl) -4- (4-nitrophenylazo) aniline as sold under the name Disperse Red 1 by Sigma Aldrich, Disperse Red 19 dye marketed by Sigma Aldrich, 4- (4-nitrophenylazo) aniline as sold under the name Disperse Orange 3 by Sigma Aldrich, 2- [4- (2-chloro-4-nitrophenylazo) -N-ethylphenylamino] ethanol as sold under the name Disperse Red 13 by the company Sigma Aldrich, and the Sudan Red 7B dye as marketed by Sigma Aldrich;
  • triazine dyes for example 4,4 ', 4' '- s - triazine - 2,4,6 - triyl - tribenzoic acid;
  • anthraquinone dyes for example sodium 1-amino-9,10-dihydro-9,10-dioxo-4- (2,4,6-trimethylanilino) anthracene-2-sulphonate, as marketed by the company
  • sulphidic dyes for example the cyclic anhydride of 2-sulphobenzoic acid, or phenol red, for example, sold by the company Sigma Aldrich; and
  • carbonyl dyes for example 1,4-bis (pentylamino) anthraquinone, as sold under the name Oil Blue N by Sigma Aldrich.
  • phosphor or fluorophore conceivable according to the invention, there may be mentioned rhodamine-B-isothiocyanate (RBITC); fluorescein isothiocyanate (FITC); fluorescein; rhodamine; eosin; pyranine; aminoG; Texas red; the bodipy; cyanine; nanocrystals of ZnO, ZnS, CdSe, InGaP, InP, Si, Ge, GaAs, GaP, GaAsP; the rare earth ion doped sulfide, phosphate or vanadate oxide matrices, such as Y 2 0 3 : Eu, Y 2 O 2 S: Eu, BaMgAl 3 O 17 : Eu, GdB0 3 : Eu, YGdB0
  • thermochromic compound (s) it may be chosen from diacetylenic compounds, crystal violet lactone or vanadium dioxide V0 2 .
  • photochromic compounds there may be mentioned benzopyrans, naphthopyrans, spirobenzopyrans, spironaphthopyrans, spirobenzoxazines, spironaphthoxazines, fulgides and fulgimides.
  • the present invention also relates to a support material comprising a particle as defined above, and loaded in its core with at least one molecule of interest.
  • it may be an ink or a varnish.
  • the particles according to the invention are then preferably loaded at their core into at least one marking material and more particularly optical.
  • FIG. 1 represents MUF capsules incorporating PEG, by scanning electron microscopy, the capsules having a size of between 100 nm and 2 ⁇ ;
  • FIG. 2 represents MUF capsules incorporating PEG and loaded by an optical labeling molecule after supercritical CO 2 impregnation. The particles are intact and have retained the same dimensions as before the incorporation of the optical marking molecule.
  • PEG polyethylene glycol
  • a solution S3 is also prepared from 7.62 g of melamine and 14 g of formaldehyde (37% by weight solution) in 140 ml of distilled water and then heated at 70 ° C for 25 minutes to obtain a pre-solution. Melanin-formaldehyde polymer MF.
  • the IF solution 60 mL of polyvinylalcohol solution (PVA) (6.3 wt% solution), and 60 mL of sodium dodecyl sulfate (SDS) solution (0.5 wt% solution) are added to the solution S3 with stirring at 300 rpm.
  • the 60 mL of PEG solution (solution S2) is slowly added to the above mixture, the stirring speed being increased to 500 rpm.
  • This stirring step is continued for 10 minutes at room temperature to form a stable emulsion, and then the solution is heated to 86 ° C to allow growth of the shell polymer around the PEG.
  • reaction is maintained for 180 minutes with continuous stirring with the addition of 10 mL of distilled water every 60 minutes to replace the amount of water evaporated.
  • the particles are then dialyzed for 3 days.
  • the particles obtained are characterized by scanning electron microscopy. They have a size between 100 nm and 2 ⁇ .
  • the particles are then stained with supercritical CO 2 and then again characterized by scanning electron microscopy. After coloring, we notice that the particles are intact and have the same dimensions as before the coloration ( Figures 1 and 2).

Abstract

The invention relates to a particle possessing a core formed entirely or partially from at least one polymer having a glass transition temperature less than 75 °C, encapsulated in a shell formed from at least one polymer of melamine-urea-formaldehyde. The invention further relates to the implementation of such particles to convey a marker material. Finally, the invention relates to the application of the particles thus loaded, in particular for the purposes of traceability and/or authentication of a support incorporating same.

Description

Particules de mélamine-urée-formaldéhvde (MUF) contenant un polymère possédant une Tg inférieure à 75 °C.  Melamine-urea-formaldehyde (MUF) particles containing a polymer having a Tg of less than 75 ° C.
La présente invention concerne le domaine des particules de type cœur- coquille, utilisées pour véhiculer au moins une molécule d'intérêt, notamment un matériau de marquage. The present invention relates to the field of heart-shell type particles used to convey at least one molecule of interest, in particular a marking material.
Le marquage est un outil important dans le cadre de la protection des marques, de la traçabilité des produits et de la lutte contre la contrefaçon, par exemple pour les industries papetières, de la parfumerie, de la pharmacie ou des spiritueux. Marking is an important tool in the context of trademark protection, product traceability and the fight against counterfeiting, for example for the paper, perfume, pharmacy or spirits industries.
Pour authentifier de manière fiable et rapide, un produit et par ce biais, apprécier si un produit donné est ou non une contrefaçon, il est le plus souvent procédé à un marquage distinctif et invisible des produits authentiques. Les matériaux de marquage les plus usités sont des molécules colorantes, des molécules luminescentes et/ou conductrices. Ce marquage idéalement infalsifiable est très souvent caractérisable visuellement à une longueur d'onde donnée. Il est souvent privilégié l'utilisation de marqueurs dits optiques comme les molécules fluorescentes par exemple qui sont invisibles à l'œil nu mais se révèlent en revanche, en réponse à une exposition UV. D'une manière générale, ces molécules, sont immobilisées au niveau d'un support sous une forme associée à un matériau annexe qui possède à leur égard une fonction de véhicule et permet leur immobilisation de manière pérenne au niveau du support. Ce matériau permet en outre de les protéger lors de leur stockage et les rend compatibles avec un usage dans une grande diversité de supports. Par exemple, ce matériau annexe, véhiculant le marqueur, peut être introduit dans une encre, une peinture ou un vernis qui est ensuite déposé en surface du support à traiter.  To authenticate reliably and quickly, a product and through this, to assess whether a given product is or not a counterfeit, it is most often carried out a distinctive and invisible marking of genuine products. The most commonly used marking materials are coloring molecules, luminescent and / or conductive molecules. This ideally unfalsifiable marking is very often visually characterizable at a given wavelength. It is often preferred to use so-called optical markers such as fluorescent molecules, for example, which are invisible to the naked eye but which, on the other hand, reveal themselves in response to UV exposure. In general, these molecules are immobilized at the level of a support in a form associated with an ancillary material which has a vehicle function for them and allows them to be immobilized in a permanent manner at the level of the support. This material also makes it possible to protect them during storage and makes them compatible with use in a wide variety of media. For example, this ancillary material carrying the marker may be introduced into an ink, paint or varnish which is then deposited on the surface of the support to be treated.
Toutefois, le caractère hydrophobe marqué de ces molécules de marquage voire leur fragilité, limitent significativement les modes de conditionnement envisageables pour les véhiculer.  However, the marked hydrophobic character of these marking molecules, or even their fragility, significantly limit the conditioning modes that can be envisaged for conveying them.
Ainsi, le document US 6,863,923 décrit une pâte d'impression basée sur un pré-condensat à base de polyorganosiloxanes obtenus par un procédé sol-gel et constituant une matrice dans laquelle est inclue au moins un élément colorant, luminescent, conducteur et/ou catalytique. Cette pâte peut être appliquée sur un support selon la forme ou le motif désiré et densifié par traitement thermique, à une température inférieure à la température de transition vitreuse de la matrice ainsi formée. Néanmoins, la température de densification à appliquer dans ce procédé est de l'ordre de 4000 °C, ce qui constitue une limitation sérieuse du point de vue des molécules d'intérêts utilisables, par exemple de chromophores utilisables. Thus, the document US Pat. No. 6,863,923 describes a printing paste based on a pre-condensate based on polyorganosiloxanes obtained by a sol-gel process and constituting a matrix in which is included at least one coloring, luminescent, conductive element. and / or catalytic. This paste may be applied to a support in the form or pattern desired and densified by heat treatment, at a temperature below the glass transition temperature of the matrix thus formed. Nevertheless, the densification temperature to be applied in this process is of the order of 4000 ° C., which constitutes a serious limitation from the point of view of the useful molecules of interest, for example of usable chromophores.
Pour sa part, le document WO 2004/048451 , propose des polymères hydrophiles, utilisables comme encres pour des applications de sécurité et de lutte contre la fraude, et dans lesquels sont intégrées des protéines fluorescentes de protéorhodopsine. Toutefois, la fabrication et la conservation de ces encres nécessitent de basses températures, de l'ordre de 4 °C, difficilement compatibles avec des applications industrielles.  For its part, the document WO 2004/048451 proposes hydrophilic polymers that can be used as inks for security and anti-fraud applications, and in which fluoresor proteins of proteorhodopsin are integrated. However, the manufacture and preservation of these inks require low temperatures, of the order of 4 ° C, hardly compatible with industrial applications.
En conséquence, il demeure un besoin d'une technologie utile pour véhiculer des molécules d'intérêt et les immobiliser au niveau d'un support, et qui soit dénuée des limitations précitées.  Consequently, there remains a need for a useful technology for conveying molecules of interest and immobilizing them at the level of a support, and which is devoid of the aforementioned limitations.
Plus précisément, il existe un besoin d'un matériau apte à être chargé en actif, notamment de marquage, selon une technologie de mise en œuvre aisée et non limitative.  More specifically, there is a need for a material capable of being loaded with active material, in particular marking, according to an easy and non-limiting implementation technology.
Il demeure également un besoin d'un matériau utile à titre de véhicule à l'égard d'une molécule d'intérêt et dont l'immobilisation au niveau du support traité ne requiert pas de conditions opératoires spécifiques à chaque support.  There is also a need for a useful material as a vehicle with respect to a molecule of interest and whose immobilization at the level of the support treated does not require operating conditions specific to each support.
La présente invention vise précisément à répondre à ces besoins.  The present invention aims precisely to meet these needs.
Ainsi, selon un de ses aspects, la présente invention a pour objet des particules possédant un cœur formé en tout ou partie d'au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, encapsulé dans une coquille formée d'au moins un polymère de mélamine-urée-formaldéhyde.  Thus, according to one of its aspects, the subject of the present invention is particles having a core formed wholly or partly of at least one polymer having a glass transition temperature below 75 ° C., encapsulated in a shell formed from minus a melamine-urea-formaldehyde polymer.
Contre toute attente, les inventeurs ont en effet constaté que les particules d'architecture cœur-coquille conformes à l'invention s'avèrent tout particulièrement avantageuses pour véhiculer en leur cœur des molécules d'intérêt, notamment un matériau de marquage et en particulier un marqueur optique.  Unexpectedly, the inventors have indeed found that the core-shell architecture particles in accordance with the invention are particularly advantageous for conveying in their core molecules of interest, in particular a marking material and in particular a optical marker.
Au sens de l'invention, un marqueur optique est une molécule qui sous l'action d'un stimuli, par exemple un changement de pH, un changement de température, ou une exposition spectrale UV ou IR, génère un nouvel effet chromatique, par exemple un changement de couleur ou un effet luminescent, d'une durée déterminée. For the purposes of the invention, an optical marker is a molecule which, under the action of a stimulus, for example a change in pH, a change in temperature, or a UV or IR spectral exposure, generates a new chromatic effect, for example a color change or a luminescent effect, of a definite duration.
Ce marqueur optique peut notamment être choisi parmi les agents de coloration organique ou inorganique, luminophores, fluorophores, thermochromes, et photochromes.  This optical marker may especially be chosen from organic or inorganic coloring agents, phosphors, fluorophores, thermochromic and photochromic.
L'invention a également pour objet un procédé de préparation de particules selon l'invention comprenant au moins les étapes consistant à :  The subject of the invention is also a method for preparing particles according to the invention comprising at least the steps consisting in:
(i) disposer d'une phase organique contenant au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, à l'état de soluté,  (i) having an organic phase containing at least one polymer having a glass transition temperature below 75 ° C, in the solute state,
(ii) disposer d'une phase aqueuse contenant au moins les entités monomériques mélamine, urée, et formaldéhyde, destinées à former le polymère mélamine-urée- formaldéhyde (MUF),  (ii) having an aqueous phase containing at least the melamine, urea, and formaldehyde monomeric entities for forming the melamine-urea-formaldehyde (MUF) polymer,
(iii) mettre en présence la phase organique et la phase aqueuse dans des conditions propices à la formation d'une émulsion de type phase organique dans phase aqueuse,  (iii) bringing the organic phase and the aqueous phase into contact under conditions conducive to the formation of an emulsion of organic phase type in aqueous phase,
(iv) réaliser un traitement thermique de l'émulsion pour activer et/ou stimuler la polymérisation des entités monomériques et former ainsi lesdites particules à écorce polymérique MUF et dont le cœur contient le polymère possédant une température de transition vitreuse inférieure à 75 °C, et  (iv) thermally treating the emulsion to activate and / or stimulate the polymerization of the monomeric entities and thereby form said MUF polymeric bark particles and whose core contains the polymer having a glass transition temperature below 75 ° C, and
(v) isoler lesdites particules.  (v) isolating said particles.
Le procédé selon l'invention a pour avantage d'être de mise en œuvre aisée, et permet l'obtention de particules de taille bien définie et homogène.  The method according to the invention has the advantage of being easy to implement, and makes it possible to obtain particles of well-defined and homogeneous size.
En outre, le procédé permet avantageusement la croissance du MUF formant la coquille autour dudit polymère possédant une température de transition vitreuse inférieure à 75 °C.  In addition, the method advantageously allows the growth of MUF forming the shell around said polymer having a glass transition temperature of less than 75 ° C.
De préférence, en étape (i), la phase organique contient au moins un polymère possédant une température de transition vitreuse inférieure à 50 °C.  Preferably, in step (i), the organic phase contains at least one polymer having a glass transition temperature of less than 50 ° C.
Selon un mode particulier de l'invention, le traitement thermique de l'étape (iv) consiste en un chauffage à une température comprise entre 28 °C et 100 °C, de préférence comprise entre 50 °C et 99 °C.  According to a particular embodiment of the invention, the heat treatment of step (iv) consists of heating at a temperature of between 28 ° C. and 100 ° C., preferably between 50 ° C. and 99 ° C.
Selon un mode préféré de l'invention, le procédé comprend en outre une étape (vi) de dialyse. L'invention vise également un procédé pour charger une molécule d'intérêt au cœur d'une particule selon l'invention, caractérisé en ce qu'il comprend l'imprégnation de ladite particule en milieu C02 supercritique contenant une ou plusieurs molécule(s) d'intérêt. According to a preferred embodiment of the invention, the method further comprises a dialysis step (vi). The invention also relates to a method for charging a molecule of interest in the heart of a particle according to the invention, characterized in that it comprises the impregnation of said particle in a supercritical C0 2 medium containing one or more molecules (s). ) of interest.
Dans la suite du texte, les expressions « compris entre ... et ... », « allant de ... à ... » et « variant de ... à ... » sont équivalentes et entendent signifier que les bornes sont incluses, sauf mention contraire.  In the remainder of the text, the expressions "between ... and ...", "ranging from ... to ..." and "varying from ... to ..." are equivalent and mean to mean that terminals are included unless otherwise stated.
Sauf indication contraire, l'expression « comportant/comprenant un(e) » doit être comprise comme « comportant/comprenant au moins un(e) ».  Unless otherwise indicated, the expression "comprising / including a" shall be understood as "comprising / including at least one".
Particules particles
Les particules possèdent une structure cœur-coquille dans laquelle la coquille, en mélamine-urée-formaldéhyde (MUF), renferme au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, de préférence inférieure à 50 °C.  The particles have a core-shell structure in which the melamine-urea-formaldehyde (MUF) shell contains at least one polymer having a glass transition temperature of less than 75 ° C, preferably less than 50 ° C.
De préférence, les particules selon l'invention sont hydrodispersibles. Preferably, the particles according to the invention are water-dispersible.
Les particules selon l'invention peuvent être de taille nano ou micrométrique et/ou avantageusement posséder une taille moyenne comprise entre 50 nm et 200 μιη. The particles according to the invention may be of nano or micrometric size and / or advantageously have an average size of between 50 nm and 200 μιη.
Ainsi, en particulier, la présente invention concerne une particule possédant un cœur formé en tout ou partie d'au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, encapsulé dans une coquille formée d'au moins un polymère de mélamine-urée-formaldéhyde, ladite particule possédant une taille moyenne comprise entre 50 nm et 200 μιη.  Thus, in particular, the present invention relates to a particle having a core formed wholly or partly of at least one polymer having a glass transition temperature below 75 ° C, encapsulated in a shell formed of at least one melamine polymer -urea-formaldehyde, said particle having an average size of between 50 nm and 200 μιη.
Préférentiellement, la taille moyenne des particules est comprise entre 1 μηι et 20 μιη. A l'échelle du nanomètre, la taille des particules est préférentiellement comprise entre 50 nm et 200 nm.  Preferably, the average particle size is between 1 μηι and 20 μιη. At the nanometer scale, the particle size is preferably between 50 nm and 200 nm.
Cette taille peut être déterminée par microscopie électronique à balayage.  This size can be determined by scanning electron microscopy.
La taille des facteurs de l'invention peut être notamment ajustée par les paramètres retenus pour la polymérisation. Une durée prolongée de la polymérisation aura pour conséquence d'accroître la taille des particules.  The size of the factors of the invention may in particular be adjusted by the parameters chosen for the polymerization. A prolonged duration of the polymerization will result in increasing the size of the particles.
D'une manière générale, les particules selon l'invention sont non poreuses. Avantageusement, le polymère possédant une température de transition vitreuse inférieure à 75 °C et le MUF sont associés dans un rapport pondéral polymère/MUF variant de 1 % à 10 %. Le polymère mélamme-urée- formaldéhyde (MUF) In general, the particles according to the invention are non-porous. Advantageously, the polymer having a glass transition temperature below 75 ° C. and the MUF are combined in a polymer / MUF weight ratio varying from 1% to 10%. The melamine-urea-formaldehyde (MUF) polymer
Le mélamine-urée-formaldéhyde (MUF) est un polymère thermodurcissable appartenant à la famille des aminoplastes, polymères très répandus et très utilisés dans de nombreux domaines comme par exemple dans l'industrie du bois en tant qu'adhésifs, dans la fabrication de matériel électrique ou d'ustensiles de cuisine en tant que revêtement notamment de qualité alimentaire, dans la fabrication de vernis, de peinture...  Melamine-urea-formaldehyde (MUF) is a thermosetting polymer belonging to the family of aminoplasts, polymers that are widely used and widely used in many fields such as in the wood industry as adhesives, in the manufacture of materials electric or kitchen utensils as coating including food grade, in the manufacture of varnish, paint ...
Un tel matériau est avantageux à plusieurs titres :  Such a material is advantageous in several ways:
- il n'est pas coloré ce qui permet de l'utiliser comme matériau de surface,  it is not colored, which makes it possible to use it as a surface material,
- il possède une dureté et une rigidité très importantes ainsi qu'une très grande résistance à l'abrasion,  it has a very high hardness and rigidity as well as a very high resistance to abrasion,
- il possède une très bonne résistance thermique et chimique,  - it has a very good thermal and chemical resistance,
- il possède une très bonne tenue à la lumière.  - it has a very good resistance to light.
Selon le procédé de l'invention, le polymère mélamine-urée-formaldéhyde est formé par une réaction de polymérisation, ou encore dite de condensation, entre la mélamine (M), l'urée (U) et le formaldéhyde (F), autour du cœur d'intérêt. Cette synthèse, notamment illustrée en exemple 1 ci-après, relève clairement des compétences de l'homme de l'art.  According to the process of the invention, the melamine-urea-formaldehyde polymer is formed by a polymerization or condensation reaction between melamine (M), urea (U) and formaldehyde (F), around heart of interest. This synthesis, particularly illustrated in example 1 below, clearly falls within the skills of those skilled in the art.
Avantageusement, les unités (M), (U) et (F) sont mis en œuvre dans des proportions pondérales égales à 2,5 / 1 / 8,5. Les propriétés mécaniques de la particule sont notamment proportionnelles à la proportion en formaldéhyde.  Advantageously, the units (M), (U) and (F) are used in proportions by weight equal to 2.5 / 1 / 8.5. The mechanical properties of the particle are in particular proportional to the proportion of formaldehyde.
Les particules de MUF peuvent notamment être obtenues selon le procédé décrit par Liu, X. et al (Liu, X, et al. Macromolecular Materials and Engineering, 2009, 294, 389-395).  The MUF particles can in particular be obtained according to the method described by Liu, X. et al (Liu, X, et al., Macromolecular Materials and Engineering, 2009, 294, 389-395).
Selon un mode de réalisation particulier, l'écorce des particules peut également inclure de la silice ou de l'organo silice. Leur présence dans le milieu réactionnel lors de la polymérisation des entités monomériques dédiées à former le MUF, va conduire à leur incorporation dans l'écorce. La présence de ces matériaux annexes est notamment avantageuse pour conférer, si nécessaire, des fonctionnalités de surfaces annexes aux particules selon l'invention via des agents de couplage spécifiques, tels que par exemple le triméthoxysilane. Polymère possédant une température de transition vitreuse inférieure à 75 °CAccording to a particular embodiment, the particle bark may also include silica or organo-silica. Their presence in the reaction medium during the polymerization of the monomeric entities dedicated to form the MUF will lead to their incorporation into the bark. The presence of these ancillary materials is particularly advantageous for conferring, if necessary, surface functionalities ancillary to the particles according to the invention via specific coupling agents, such as, for example, trimethoxysilane. Polymer having a glass transition temperature below 75 ° C
Le polymère formant en tout ou partie le cœur des particules possède de préférence une température de transition vitreuse comprise entre 30 °C et 75 °C, de préférence comprise entre 30 °C et 50 °C. The polymer forming all or part of the core of the particles preferably has a glass transition temperature between 30 ° C and 75 ° C, preferably between 30 ° C and 50 ° C.
Dans le cadre de la présente invention, on entend par « température de transition vitreuse » ou « Tg », le changement d'état du polymère ou du matériau polymérisé, sous l'action de la température, entraînant des variations importantes de ses propriétés mécaniques. En dessous de cette température, le polymère est dit vitreux (état solide) et présente le comportement d'un corps solide élastique. Au dessus de cette température, le polymère présente un comportement de solide plastique (état viscoélastique), suite à l'affaiblissement de liaisons intermoléculaires (force de Van der Waals...).  In the context of the present invention, the term "glass transition temperature" or "Tg" means the change of state of the polymer or of the polymerized material, under the action of the temperature, causing significant variations in its mechanical properties. . Below this temperature, the polymer is said to be vitreous (solid state) and exhibits the behavior of an elastic solid body. Above this temperature, the polymer exhibits a behavior of plastic solid (viscoelastic state), following the weakening of intermolecular bonds (Van der Waals force ...).
Les polymères convenant selon l'invention s'avèrent en outre avantageusement compatibles avec un procédé d'imprégnation en milieu supercritique et plus particulièrement en milieu C02 supercritique. The polymers that are suitable according to the invention also prove to be advantageously compatible with an impregnation process in a supercritical medium and more particularly in a supercritical C0 2 medium.
Ainsi, le polymère formant le cœur des particules, selon la présente invention peut être avantageusement choisi parmi les polyéthylènes glycol, les polyvinylpyrrolidones, les polyéthylméthacrylates, les dérivés d'alcools polyvinyliques, les polystyrènes, les latex, les polyéthylènes, les polypropylènes et leurs mélanges.  Thus, the polymer forming the core of the particles according to the present invention may advantageously be chosen from polyethylene glycols, polyvinylpyrrolidones, polyethylmethacrylates, derivatives of polyvinyl alcohols, polystyrenes, latices, polyethylenes, polypropylenes and their mixtures. .
En particulier, le polymère formant le cœur des particules est choisi parmi les polyéthylène glycol, polyoxyethylene stéarate, chlorure de poly(vinylidene co-vinyl), polyvinylpyrrolidone, poly(vinyl butyral-co-vinyl alcool-co-vinyl acétate), poly(maleic anhydride-act-l-octadecene), chlorure de poly(vinyl) et les dérivés d'alcool polyvinylique.  In particular, the polymer forming the core of the particles is chosen from polyethylene glycol, polyoxyethylene stearate, poly (vinylidene co-vinyl chloride), polyvinylpyrrolidone, poly (vinyl butyral-co-vinyl alcohol-co-vinyl acetate), poly ( maleic anhydride-act-1-octadecene), polyvinyl chloride and polyvinyl alcohol derivatives.
De préférence, il s'agit d'un polyéthylène glycol, notamment de poids moléculaire variant de 400 g.mof1 à 40000 g.mol"1 et notamment d'environ 6000 g.mol4. Procédé de préparation des particules Preferably, it is a polyethylene glycol, in particular of molecular weight ranging from 400 gmol 1 to 40000 gmol -1 and in particular about 6000 gmol 4 . Process for preparing the particles
La présente invention vise en outre un procédé de préparation de particules comprenant les étapes suivantes :  The present invention further provides a method of preparing particles comprising the steps of:
(i) disposer d'une phase organique, notamment non miscible à l'eau, contenant au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, notamment à l'état de soluté,  (i) having an organic phase, in particular immiscible with water, containing at least one polymer having a glass transition temperature below 75 ° C., especially in the solute state,
(ii) disposer d'une phase aqueuse contenant au moins les entités monomériques mélamine, urée, et formaldéhyde, destinées à former le polymère mélamine-urée- formaldéhyde (MUF),  (ii) having an aqueous phase containing at least the melamine, urea, and formaldehyde monomeric entities for forming the melamine-urea-formaldehyde (MUF) polymer,
(iii) mettre en présence la phase organique et la phase aqueuse dans des conditions propices à la formation d'une émulsion de type phase organique dans phase aqueuse,  (iii) bringing the organic phase and the aqueous phase into contact under conditions conducive to the formation of an emulsion of organic phase type in aqueous phase,
(iv) réaliser un traitement thermique de l'émulsion pour activer et/ou stimuler la polymérisation des entités monomériques et former ainsi lesdites particules à écorce polymérique MUF et dont le cœur contient le polymère possédant une température de transition vitreuse inférieure à 75 °C, et  (iv) thermally treating the emulsion to activate and / or stimulate the polymerization of the monomeric entities and thereby form said MUF polymeric bark particles and whose core contains the polymer having a glass transition temperature below 75 ° C, and
(v) isoler lesdites particules.  (v) isolating said particles.
En particulier, la présente invention vise en outre un procédé de préparation de particules comprenant les étapes suivantes :  In particular, the present invention further provides a method of preparing particles comprising the following steps:
(i) disposer d'une phase organique, notamment non miscible à l'eau, contenant au moins un polyéthylène glycol, notamment à l'état de soluté,  (i) having an organic phase, in particular immiscible with water, containing at least one polyethylene glycol, especially in the solute state,
(ii) disposer d'une phase aqueuse contenant au moins les entités monomériques mélamine, urée, et formaldéhyde, destinées à former le polymère mélamine-urée- formaldéhyde (MUF),  (ii) having an aqueous phase containing at least the melamine, urea, and formaldehyde monomeric entities for forming the melamine-urea-formaldehyde (MUF) polymer,
(iii) mettre en présence la phase organique et la phase aqueuse dans des conditions propices à la formation d'une émulsion de type phase organique dans phase aqueuse,  (iii) bringing the organic phase and the aqueous phase into contact under conditions conducive to the formation of an emulsion of organic phase type in aqueous phase,
(iv) réaliser un traitement thermique de l'émulsion pour activer et/ou stimuler la polymérisation des entités monomériques et former ainsi lesdites particules à écorce polymérique MUF et dont le cœur contient le polyéthylène glycol, et  (iv) effecting a heat treatment of the emulsion to activate and / or stimulate the polymerization of the monomeric entities and thereby form said particles with polymeric MUF bark and whose core contains polyethylene glycol, and
(v) isoler lesdites particules. Phase organique (v) isolating said particles. Organic phase
Le procédé selon l'invention nécessite tout d'abord de disposer d'une phase organique contenant le ou les polymère(s) possédant une température de transition vitreuse inférieure à 75 °C à encapsuler.  The process according to the invention firstly requires an organic phase containing the polymer (s) having a glass transition temperature below 75 ° C to be encapsulated.
Le choix du solvant organique ou mélange de solvants organiques est donc avantageusement choisi au regard de la nature du polymère possédant une température de transition vitreuse inférieure à 75 °C, à traiter selon l'invention. Par ailleurs, il est également choisi au regard de son défaut de solubilité en milieu aqueux pour précisément obtenir une émulsion correspondante lors de sa mise en contact avec la phase aqueuse.  The choice of the organic solvent or mixture of organic solvents is therefore advantageously chosen with regard to the nature of the polymer having a glass transition temperature below 75 ° C., to be treated according to the invention. Moreover, it is also chosen in view of its lack of solubility in an aqueous medium to precisely obtain a corresponding emulsion when it comes into contact with the aqueous phase.
Ce choix relève des compétences de l'homme de l'art.  This choice is within the skill of those skilled in the art.
Le solvant peut être volatil ou non et est de préférence choisi parmi le dichlorométhane, le cyclohexane, le toluène, ou l'heptane.  The solvent may or may not be volatile and is preferably chosen from dichloromethane, cyclohexane, toluene or heptane.
La phase organique peut comprendre de 1 % à 20 % en poids de polymère(s) possédant une température de transition vitreuse inférieure à 75 °C par rapport à son poids total.  The organic phase may comprise from 1% to 20% by weight of polymer (s) having a glass transition temperature of less than 75 ° C relative to its total weight.
Phase aqueuse Aqueous phase
Le procédé selon l'invention nécessite également de disposer d'une phase aqueuse.  The process according to the invention also requires the provision of an aqueous phase.
Cette phase aqueuse contient au moins la mélamine (M), l'urée (U), et le formaldéhyde (F), tels que définis précédemment.  This aqueous phase contains at least melamine (M), urea (U), and formaldehyde (F), as defined above.
La phase aqueuse peut comprendre de l'eau et le cas échéant contenir en outre un polymère hydrosoluble.  The aqueous phase may comprise water and optionally further contain a water-soluble polymer.
Par « polymère hydrosoluble », on désigne dans le cadre de la présente invention un composé liquide à température ambiante et miscible à l'eau (miscibilité dans l'eau supérieure à 50 % en poids à 25 °C et sous pression atmosphérique).  By "water-soluble polymer" is meant in the context of the present invention a liquid compound at room temperature and miscible with water (miscibility in water greater than 50% by weight at 25 ° C and at atmospheric pressure).
Les polymères hydrosolubles utilisables dans les compositions selon l'invention peuvent ou non être volatils.  The water-soluble polymers that can be used in the compositions according to the invention may or may not be volatile.
Parmi les polymères hydrosolubles pouvant être utilisés dans les compositions conformes à l'invention, on peut notamment citer l'alcool polyvinylique (PVA), la polyoxazoline, la polyvinylpyrrolidone (PVP), la gélatine, la cellulose et l'hydroxyalkyl cellulose, les chitosans, et les chitines. L'alcool polyvinylique permet notamment d'obtenir des particules de taille micrométrique, du fait de sa capacité à stabiliser les particules de plus grosses tailles. Among the water-soluble polymers that can be used in the compositions in accordance with the invention, mention may be made especially of polyvinyl alcohol (PVA), polyoxazoline, polyvinylpyrrolidone (PVP), gelatin, cellulose and hydroxyalkyl cellulose, chitosans , and chitin. In particular, polyvinyl alcohol makes it possible to obtain particles of micrometric size, because of its ability to stabilize larger particles.
Comme il ressort de ce qui précède, le MUF et le(s) polymère(s) possédant une température de transition vitreuse inférieure à 75 °C sont mis en présence dans des quantités ajustées de sorte que les particules possèdent un rapport pondéral polymère(s)/MUF variant de 1 % à 10 %.  As is apparent from the foregoing, the MUF and the polymer (s) having a glass transition temperature below 75 ° C are contacted in controlled amounts so that the particles have a polymeric weight ratio (s). ) / MUF ranging from 1% to 10%.
Tensioactif surfactant
Selon une variante préférée de l'invention, Pémulsion est formée en présence d'au moins un tensioactif.  According to a preferred variant of the invention, the emulsion is formed in the presence of at least one surfactant.
Avantageusement, le(s) tensioactif(s) est(sont) présent(s) initialement dans la phase aqueuse.  Advantageously, the (s) surfactant (s) is (are) present (s) initially in the aqueous phase.
Les tensioactifs convenant à l'invention peuvent être choisis parmi toutes les catégories de tensioactifs (anioniques, cationiques, non ioniques ou amphotères). Plus précisément, ils peuvent être choisis parmi les tensioactifs conventionnellement mis en œuvre dans les procédés d'émulsifi cation de la phase organique considérée. C'est ainsi que pour obtenir des émulsions de type phase organique dans eau, on choisit des agents tensioactifs possédant une balance hydrophile/lipophile (HLB) supérieure à 14.  The surfactants that are suitable for the invention may be chosen from any of the classes of surfactants (anionic, cationic, nonionic or amphoteric). More specifically, they may be chosen from surfactants conventionally used in the processes for emulsification of the organic phase under consideration. Thus, to obtain emulsions of organic phase type in water, surfactants having a hydrophilic / lipophilic balance (HLB) greater than 14 are chosen.
Les agents tensioactifs utilisables selon l'invention sont avantageusement non amphotères et peuvent être plus particulièrement choisis parmi les agents tensioactifs anioniques, cationiques et non ioniques.  The surfactants that may be used according to the invention are advantageously non-amphoteric and may be more particularly chosen from anionic, cationic and nonionic surfactants.
Avantageusement, on solubilise préalablement le ou les agents tensioactifs dans la phase aqueuse. Les agents tensioactifs sont mis en œuvre dans le procédé selon l'invention à une quantité réduite et de préférence variant entre 0,1 % et 10 % en poids, exprimé par rapport au poids de la phase aqueuse.  Advantageously, the surfactant (s) are solubilized beforehand in the aqueous phase. The surfactants are used in the process according to the invention in a reduced amount and preferably between 0.1% and 10% by weight, expressed relative to the weight of the aqueous phase.
Le tensioactif est par exemple choisi parmi le dodécyle sulfate de sodium (SDS), le bromure de cétyltriméthylammonium, les poloxamères tels que commercialisés sous les appellations Pluronic par la société BASF, et les tensioactifs commercialisés sous les appellations IGEPAL® et Tritons® X. The surfactant is for example selected from sodium dodecyl sulfate (SDS), cetyltrimethyl ammonium bromide, such as the poloxamers sold under the names Pluronic by BASF, and surfactants sold under the designations IGEPAL ® and Triton ® X.
Selon un mode préféré de l'invention, le tensioactif utilisé est le dodécyle sulfate de sodium (SDS). Emulsion According to a preferred embodiment of the invention, the surfactant used is sodium dodecyl sulphate (SDS). Emulsion
Les deux phases, organique et aqueuse, sont mises en présence dans des conditions propices à la réalisation d'une émulsion stable, à température ambiante, sous agitation.  The two phases, organic and aqueous, are brought together under conditions conducive to the production of a stable emulsion at room temperature, with stirring.
L'agitation est maintenue à vitesse lente lors de l'ajout du(des) polymère(s) possédant une température de transition vitreuse inférieure à 75 °C puis augmentée pour obtenir une agitation vigoureuse et produire émulsion stable.  The stirring is maintained at a slow rate when adding the polymer (s) having a glass transition temperature below 75 ° C and then increased to obtain a vigorous stirring and produce stable emulsion.
De manière avantageuse, la solution contenant le(s) polymère(s) possédant une température de transition vitreuse inférieure à 75 °C est introduite lentement dans le mélange contenant le pré-polymère mélamine-formaldéhyde et l'urée, afin de favoriser la croissance du MUF formant la coquille autour du ou des polymères.  Advantageously, the solution containing the polymer (s) having a glass transition temperature below 75 ° C. is introduced slowly into the mixture containing the melamine-formaldehyde prepolymer and the urea, in order to promote the growth. of the MUF forming the shell around the polymer (s).
Avantageusement, l'agitation est maintenue à 300 rpm puis augmentée à 500 rpm pour obtenir Pémulsion stable.  Advantageously, the stirring is maintained at 300 rpm and then increased to 500 rpm to obtain the stable emulsion.
Cette agitation, généralement mécanique, est prolongée d'un délai suffisant pour obtenir P émulsion attendue.  This stirring, generally mechanical, is prolonged by a sufficient time to obtain the expected emulsion.
Selon un mode particulier de réalisation, l'agitation est maintenue pendant 10 minutes.  According to a particular embodiment, stirring is maintained for 10 minutes.
A l'issue de cette étape, une émulsion, formée de gouttelettes de phase organique dispersées dans une phase aqueuse, est obtenue.  At the end of this step, an emulsion, formed of droplets of organic phase dispersed in an aqueous phase, is obtained.
Il est à la portée de l'homme de l'art d'ajuster la taille des gouttelettes en modulant la nature du solvant organique, du ou des tensioactif(s) retenu(s), et du polymère hydrosoluble, mais également en modulant la vitesse d'agitation utilisée. Le procédé selon l'invention comprend ensuite une étape de chauffage de l'émulsion, sous agitation, pendant un délai suffisant pour transformer les gouttelettes de Γ émulsion à l'état de particules. Les unités M, U, et F polymérisent pour former le MUF qui s'organise autour du cœur d'intérêt pour former les particules attendues.  It is within the abilities of those skilled in the art to adjust the size of the droplets by modulating the nature of the organic solvent, the surfactant (s) retained (s), and the water-soluble polymer, but also by modulating the stirring speed used. The method according to the invention then comprises a step of heating the emulsion, with stirring, for a time sufficient to transform the droplets of Γ emulsion in the form of particles. The units M, U, and F polymerize to form the MUF which is organized around the heart of interest to form the expected particles.
Le chauffage considéré dans le procédé selon l'invention peut être réalisé à une température variant de 28 °C à 100 °C, de préférence variant de 50 °C à 99 °C.  The heating considered in the process according to the invention can be carried out at a temperature ranging from 28 ° C. to 100 ° C., preferably ranging from 50 ° C. to 99 ° C.
Selon un mode de réalisation particulier, l'émulsion obtenue est chauffée à 86 °C pendant 180 minutes sous agitation continue à 500 rpm avec ajout de 10 mL d'eau toutes les 60 minutes afin de compenser la quantité d'eau évaporée lors du traitement thermique. According to a particular embodiment, the emulsion obtained is heated at 86 ° C. for 180 minutes with continuous stirring at 500 rpm with the addition of 10 ml of water. every 60 minutes to compensate for the amount of water evaporated during heat treatment.
Le procédé selon l'invention comprend en outre une étape consistant à isoler les particules obtenues à l'étape précédente. Elles peuvent notamment être isolées par filtration tangentielle ou frontale du milieu liquide le contenant. Les particules de plus petites tailles peuvent notamment être isolées par ultrafiltration.  The method according to the invention further comprises a step of isolating the particles obtained in the previous step. They can in particular be isolated by tangential or frontal filtration of the liquid medium containing it. The particles of smaller sizes can in particular be isolated by ultrafiltration.
Ces particules subissent avantageusement une centrifugation en milieu alcoolique.  These particles advantageously undergo centrifugation in an alcoholic medium.
Enfin, les particules sont de préférence dialysées pendant plusieurs jours.  Finally, the particles are preferably dialyzed for several days.
Application des particules selon l'invention à titre de véhicule pour au moins une molécule d'intérêt Application of the particles according to the invention as a vehicle for at least one molecule of interest
Comme précisé précédemment, un intérêt particulier des particules selon l'invention est leur compatibilité avec un mode d'imprégnation du polymère formant leur cœur en un milieu C02 supercritique. As stated above, a particular interest of the particles according to the invention is their compatibility with a mode of impregnation of the polymer forming their core in a supercritical CO 2 medium.
Un procédé d'imprégnation d'un polymère par un solvant supercritique offre en effet l'avantage significatif de s'affranchir des solvants organiques, utilisés pour les méthodes traditionnelles d'imprégnation et qui sont susceptibles de poser des problèmes de toxicité à plus ou moins grande échelle.  A process for impregnating a polymer with a supercritical solvent indeed offers the significant advantage of being free from organic solvents, used for traditional impregnation methods and which are likely to pose toxicity problems more or less large scale.
Les inventeurs ont ainsi constaté que les particules à architecture cœur-coquille selon l'invention se prêtent à ce phénomène de charge par imprégnation en milieu C02 supercritique. Le C02 supercritique est particulièrement intéressant pour l'imprégnation par adsorption au regard de son importante diffusivité, de sa densité élevée, et de sa faible viscosité. The inventors have thus found that the core-shell architecture particles according to the invention lend themselves to this charging phenomenon by impregnation in a supercritical C0 2 medium. Supercritical CO 2 is particularly interesting for adsorption impregnation with regard to its high diffusivity, its high density, and its low viscosity.
Contre toute attente, le matériau formant l'écorce des particules ne fait pas obstacle à l'imprégnation du polymère, formant le cœur des particules, par une molécule d'intérêt en milieu C02 supercritique. Unexpectedly, the material forming the bark of the particles does not prevent impregnation of the polymer, forming the core of the particles, with a molecule of interest in a supercritical CO 2 medium.
Ainsi, un autre objet de la présente invention concerne un procédé utile pour charger au moins une molécule d'intérêt au cœur d'une particule selon l'invention comprenant l'imprégnation de ladite particule en milieu C02 supercritique contenant une ou plusieurs molécule(s) d'intérêt. Plus précisément, la présente invention vise également un procédé utile pour préparer une particule selon l'invention chargée en au moins une molécule d'intérêt, comprenant au moins les étapes consistant à : Thus, another object of the present invention relates to a method useful for charging at least one molecule of interest in the heart of a particle according to the invention comprising impregnating said particle in a supercritical CO 2 medium containing one or more molecules ( s) of interest. More specifically, the present invention also provides a process useful for preparing a particle according to the invention loaded into at least one molecule of interest, comprising at least the steps of:
- disposer de ladite molécule d'intérêt en milieu C02 supercritique, to dispose of said molecule of interest in a supercritical C0 2 medium,
- mettre en présence ledit milieu C02 contenant ladite molécule avec au moins une particule selon l'invention dans des conditions propices à l'imprégnation du polymère formant le cœur de ladite particule avec ladite molécule, et placing said C0 2 medium containing said molecule with at least one particle according to the invention in conditions conducive to the impregnation of the polymer forming the core of said particle with said molecule, and
- récupérer les particules chargées en molécule d'intérêt.  - recover the charged particles in molecule of interest.
Par exemple, ledit milieu C02 contenant ladite molécule peut être mis en présence avec au moins une particule selon l'invention sous une pression comprise entre 200 bar et 350 bar, de préférence comprise entre 250 bar et 300 bar. For example, said medium C0 2 containing said molecule can be brought into contact with at least one particle according to the invention under a pressure of between 200 bar and 350 bar, preferably between 250 bar and 300 bar.
Selon un mode de réalisation particulier, ledit milieu C02 contenant ladite molécule est mis en présence avec au moins une particule selon l'invention à une température comprise entre 70 °C et 90 °C, de préférence égale à 80 °C, plus particulièrement pendant une durée comprise entre 45 minutes et 75 minutes, de préférence égale à 60 minutes. According to a particular embodiment, said medium C0 2 containing said molecule is brought into contact with at least one particle according to the invention at a temperature between 70 ° C and 90 ° C, preferably equal to 80 ° C, more particularly for a period of between 45 minutes and 75 minutes, preferably equal to 60 minutes.
Selon encore un mode de réalisation particulier, la mise en présence dudit milieu C02 contenant ladite molécule avec au moins une particule selon l'invention est effectuée en présence d'un co-solvant, par exemple du tétrahydrofurane (THF). According to another particular embodiment, placing said CO 2 medium containing said molecule with at least one particle according to the invention is carried out in the presence of a co-solvent, for example tetrahydrofuran (THF).
Molécule d'intérêt Molecule of interest
Les particules considérées selon l'invention peuvent être en outre chargées en leur cœur avec au moins une molécule d'intérêt.  The particles considered according to the invention can be further loaded in their core with at least one molecule of interest.
Ces molécules d'intérêt peuvent être tout composé possédant une affinité avec le polymère possédant une température de transition vitreuse inférieure à 75 °C formant leur cœur.  These molecules of interest may be any compound having an affinity with the polymer having a glass transition temperature below 75 ° C forming their core.
A ce titre, les particules selon l'invention sont tout particulièrement avantageuses pour véhiculer des molécules à caractère hydrophobe.  In this respect, the particles according to the invention are particularly advantageous for transporting hydrophobic molecules.
Au regard du domaine d'application plus particulièrement considéré selon l'invention, à savoir celui du marquage, les particules selon l'invention s'avèrent tout particulièrement intéressantes pour véhiculer une grande diversité de marqueurs, et notamment de marqueurs optiques. Ainsi, selon l'invention, une molécule d'intérêt peut être un matériau de marquage et de préférence un marqueur optique. In view of the field of application more particularly considered according to the invention, namely that of the marking, the particles according to the invention prove to be particularly interesting for conveying a great diversity of markers, and in particular of optical markers. Thus, according to the invention, a molecule of interest may be a marking material and preferably an optical marker.
Comme précisé ci-dessus, l'invention vise donc également l'utilisation d'une particule selon l'invention et chargée en son cœur avec au moins un matériau de marquage, comme outil de marquage.  As specified above, the invention therefore also relates to the use of a particle according to the invention and loaded in its core with at least one marking material, as a marking tool.
Les particules selon l'invention ont en effet pour avantage de ne pas porter préjudice à la réactivité de la molécule d'intérêt qu'elles véhiculent en leur cœur. Dans le cas d'un marqueur optique, ce dernier demeure caractérisable bien que localisé au cœur de ladite particule.  The particles according to the invention have the advantage of not harming the reactivity of the molecule of interest that they carry in their heart. In the case of an optical marker, the latter remains characterizable although located in the heart of said particle.
Ces marqueurs optiques peuvent notamment être choisis parmi les agents de colorations organiques ou inorganiques, les luminophores ou fluorophores, les thermochromes, les fluorophores, ou les photochromes.  These optical markers may especially be chosen from organic or inorganic coloring agents, phosphors or fluorophores, thermochromes, fluorophores, or photochromes.
Parmi les agents de colorations organiques ou inorganiques, on peut notamment citer :  Among the organic or inorganic coloring agents, there may be mentioned in particular:
- les colorants azoïques, par exemple le N-éthyl-N-(2-hydroxyéthyl)-4-(4- nitrophenylazo) aniline tel que commercialisé sous la dénomination Disperse Red 1 par la société Sigma Aldrich, le colorant Disperse Red 19 commercialisé par la société Sigma Aldrich, le 4-(4-Nitrophenylazo)aniline tel que commercialisé sous la dénomination Disperse Orange 3 par la société Sigma Aldrich, le 2-[4-(2-Chloro-4-nitrophenylazo)-N- ethylphenylamino]ethanol tel que commercialisé sous la dénomination Disperse Red 13 par la société Sigma Aldrich, et le colorant Sudan Red 7B tel que commercialisé par la société Sigma Aldrich ;  azo dyes, for example N-ethyl-N- (2-hydroxyethyl) -4- (4-nitrophenylazo) aniline as sold under the name Disperse Red 1 by Sigma Aldrich, Disperse Red 19 dye marketed by Sigma Aldrich, 4- (4-nitrophenylazo) aniline as sold under the name Disperse Orange 3 by Sigma Aldrich, 2- [4- (2-chloro-4-nitrophenylazo) -N-ethylphenylamino] ethanol as sold under the name Disperse Red 13 by the company Sigma Aldrich, and the Sudan Red 7B dye as marketed by Sigma Aldrich;
- les colorants triazine, par exemple l'acide 4,4',4''-s-Triazine-2,4,6-triyl-tribenzoïque ; triazine dyes, for example 4,4 ', 4' '- s - triazine - 2,4,6 - triyl - tribenzoic acid;
- les colorants anthraquinones, par exemple le l-amino-9,10-dihydro-9,10-dioxo-4-(2,4,6- trimethylanilino)anthracene-2-sulphonate de sodium tel que commercialisé par la sociétéanthraquinone dyes, for example sodium 1-amino-9,10-dihydro-9,10-dioxo-4- (2,4,6-trimethylanilino) anthracene-2-sulphonate, as marketed by the company
Sigma Aldrich sous la dénomination Acid Blue 129, le 1-aminoanthraquinone, l'Alizarin Red S par exemple commercialisé par la société Sigma Aldrich, ou encore le Foron Bleu commercialisé par la société Clariant ; Sigma Aldrich under the name Acid Blue 129, 1-aminoanthraquinone, Alizarin Red S for example marketed by Sigma Aldrich, or the Blue Foron marketed by Clariant;
- les colorants sulfurés, par exemple l'anhydride cyclique de l'acide 2-sulfobenzoïque, ou le rouge de phénol par exemple commercialisé par la société Sigma Aldrich ; et  sulphidic dyes, for example the cyclic anhydride of 2-sulphobenzoic acid, or phenol red, for example, sold by the company Sigma Aldrich; and
- les colorants carbonylés, par exemple le l,4-bis(pentylamino)anthraquinone tel que commercialisé sous la dénomination Oil Blue N par la société Sigma Aldrich. A titre de luminophore ou de fluorophore envisageables selon l'invention, on peut notamment citer la rhodamine-B-isothiocyanate (RBITC) ; la fluorescéine isothiocyanate (FITC) ; la fluorescéine ; la rhodamine ; l'éosine ; la pyranine ; l'aminoG ; le rouge Texas ; le bodipy ; la cyanine ; les nanocristaux de ZnO, ZnS, CdSe, InGaP, InP, Si, Ge, GaAs, GaP, GaAsP ; les matrices d'oxyde de sulfure, de phosphate ou de vanadate dopées par un ion de terre rare, telles que Y203:Eu, Y202S:Eu, BaMgAli6017:Eu, GdB03:Eu, YGdB03:Eu, YPV04:Eu, Gd203:Tb, Gd202S:Tb, Y3Al50i2:Tb, Y2Si05:Ce, LaP04:Tb,Ce ; les matrices de semi-conducteurs ou d'oxydes dopées par un métal de transition, telles que ZnS:Mn, ZnS:Au, ZnS:Al, ZnS:Ag, ZnO:Ag, ZnO:Cu, ZnO:Mn, Zn2Si04:Mn, Al203:Cr, Al203:Ti. carbonyl dyes, for example 1,4-bis (pentylamino) anthraquinone, as sold under the name Oil Blue N by Sigma Aldrich. As phosphor or fluorophore conceivable according to the invention, there may be mentioned rhodamine-B-isothiocyanate (RBITC); fluorescein isothiocyanate (FITC); fluorescein; rhodamine; eosin; pyranine; aminoG; Texas red; the bodipy; cyanine; nanocrystals of ZnO, ZnS, CdSe, InGaP, InP, Si, Ge, GaAs, GaP, GaAsP; the rare earth ion doped sulfide, phosphate or vanadate oxide matrices, such as Y 2 0 3 : Eu, Y 2 O 2 S: Eu, BaMgAl 3 O 17 : Eu, GdB0 3 : Eu, YGdB0 3 : Eu, YPVO 4 : Eu, Gd 2 O 3 : Tb, Gd 2 O 2 S: Tb, Y 3 Al 5 OI 2 : Tb, Y 2 SiO 5 : Ce, LaPO 4 : Tb, Ce; semiconductor matrices or transition metal-doped oxides, such as ZnS: Mn, ZnS: Au, ZnS: Al, ZnS: Ag, ZnO: Ag, ZnO: Cu, ZnO: Mn, Zn 2 SiO 4 : Mn, Al 2 O 3 : Cr, Al 2 O 3 : Ti.
Quant au(x) composé(s) thermochrome(s), il(s) peu(ven)t être choisi(s) parmi les composés diacétyléniques, la lactone cristal violet ou le dioxyde de vanadium V02. As for the thermochromic compound (s), it may be chosen from diacetylenic compounds, crystal violet lactone or vanadium dioxide V0 2 .
Parmi les photochromes, on peut notamment citer les benzopyrannes, les naphtopyrannes, les spirobenzopyrannes, les spironaphtopyrannes, les spirobenzoxazines, les spironaphtoxazines, les fulgides et les fulgimides.  Among the photochromic compounds, there may be mentioned benzopyrans, naphthopyrans, spirobenzopyrans, spironaphthopyrans, spirobenzoxazines, spironaphthoxazines, fulgides and fulgimides.
La présente invention concerne également un matériau support comprenant une particule telle que définie ci-dessus, et chargée en son cœur avec au moins une molécule d'intérêt. The present invention also relates to a support material comprising a particle as defined above, and loaded in its core with at least one molecule of interest.
Avantageusement, il peut s'agir d'une encre ou d'un vernis.  Advantageously, it may be an ink or a varnish.
Les particules selon l'invention sont alors de préférence chargées au niveau de leur cœur en au moins un matériau de marquage et plus particulièrement optique.  The particles according to the invention are then preferably loaded at their core into at least one marking material and more particularly optical.
D'autres caractéristiques, avantages et modes d'application des particules et du procédé de préparation selon l'invention, ressortiront mieux des exemples de réalisation de l'invention et de l'examen des figures annexées, présentés à titre illustratif et non limitatif du domaine de l'invention et sur lesquels : Other characteristics, advantages and modes of application of the particles and of the preparation method according to the invention will become more apparent from the exemplary embodiments of the invention and the examination of the attached figures, presented by way of illustration and not limitation of the field of the invention and in which:
- la figure 1 représente des capsules de MUF incorporant le PEG, par microscopie électronique à balayage, les capsules ayant une taille comprise entre 100 nm et 2 μπι ;  FIG. 1 represents MUF capsules incorporating PEG, by scanning electron microscopy, the capsules having a size of between 100 nm and 2 μπι;
- la figure 2 représente des capsules de MUF incorporant le PEG et chargées par une molécule de marquage optique après imprégnation au C02 supercritique. Les particules sont intactes et ont conservé les mêmes dimensions qu'avant l'incorporation de la molécule de marquage optique. FIG. 2 represents MUF capsules incorporating PEG and loaded by an optical labeling molecule after supercritical CO 2 impregnation. The particles are intact and have retained the same dimensions as before the incorporation of the optical marking molecule.
EXEMPLE Synthèse de particules MUF-PEG selon l'invention EXAMPLE Synthesis of MUF-PEG Particles According to the Invention
Une solution SI est préparée à partir de 1 ,2 g d'urée (M = 60,06 g.mol"1, Sigma Aldrich) dans 60 mL d'eau distillée à température ambiante, sous agitation (100 rpm), pendant 5 minutes. A solution SI is prepared from 1.2 g of urea (M = 60.06 gmol -1 , Sigma Aldrich) in 60 ml of distilled water at room temperature, with stirring (100 rpm), for 5 minutes. minutes.
Dans le même temps, une solution S2 est préparée à partir de 5 g de polyéthylène glycol (PEG) (M„ 6000, Sigma Aldrich) dans 60 mL de dichlorométhane (M = 84,93 g.mol"1, Sigma Aldrich). At the same time, a solution S2 is prepared from 5 g of polyethylene glycol (PEG) (Mg 6000, Sigma Aldrich) in 60 ml of dichloromethane (M = 84.93 gmol -1 , Sigma Aldrich).
Une solution S3 est également préparée à partir de 7,62 g de mélamine et 14 g de formaldéhyde (solution à 37 % en poids) dans 140 mL d'eau distillée, puis chauffée à 70 °C pendant 25 minutes pour obtenir un pré-polymère mélanine-formaldéhyde M-F.  A solution S3 is also prepared from 7.62 g of melamine and 14 g of formaldehyde (37% by weight solution) in 140 ml of distilled water and then heated at 70 ° C for 25 minutes to obtain a pre-solution. Melanin-formaldehyde polymer MF.
Dans un bêcher réactionnel, la solution SI, 60 mL de solution de polyvinylalcool (PVA) (solution à 6,3 % en poids), et 60 mL de solution de sodium dodécylsulfate (SDS) (solution à 0,5 % en poids) sont ajoutées à la solution S3 sous agitation à 300 rpm. Les 60 mL de solution de PEG (solution S2) sont ajoutées lentement au mélange précédent, la vitesse d'agitation étant augmentée à 500 rpm.  In a reaction beaker, the IF solution, 60 mL of polyvinylalcohol solution (PVA) (6.3 wt% solution), and 60 mL of sodium dodecyl sulfate (SDS) solution (0.5 wt% solution) are added to the solution S3 with stirring at 300 rpm. The 60 mL of PEG solution (solution S2) is slowly added to the above mixture, the stirring speed being increased to 500 rpm.
Cette étape d'agitation est prolongée 10 minutes, à température ambiante, afin de former une émulsion stable, puis la solution est chauffée à 86 °C afin de permettre la croissance du polymère formant une coquille autour du PEG.  This stirring step is continued for 10 minutes at room temperature to form a stable emulsion, and then the solution is heated to 86 ° C to allow growth of the shell polymer around the PEG.
La réaction est maintenue pendant 180 minutes sous agitation continue avec un ajout de 10 mL d'eau distillée toutes les 60 minutes pour remplacer la quantité d'eau évaporée.  The reaction is maintained for 180 minutes with continuous stirring with the addition of 10 mL of distilled water every 60 minutes to replace the amount of water evaporated.
Après 3 heures de réaction, les particules sont récupérées et lavées à l'éthanol à l'aide de centrifugations successives d'une durée de 10 minutes à 8000 rpm.  After 3 hours of reaction, the particles are recovered and washed with ethanol using successive centrifugations lasting 10 minutes at 8000 rpm.
Les particules sont ensuite dialysées pendant 3 jours.  The particles are then dialyzed for 3 days.
Les particules obtenues sont caractérisées en microscopie électronique à balayage. Elles présentent une taille comprise entre 100 nm et 2 μηι.  The particles obtained are characterized by scanning electron microscopy. They have a size between 100 nm and 2 μηι.
Les particules sont ensuite colorées au C02 supercritique puis de nouveau caractérisées en microscopie électronique à balayage. Après coloration, on remarque que les particules sont intactes et ont les mêmes dimensions qu'avant la coloration (Figures 1 et 2). The particles are then stained with supercritical CO 2 and then again characterized by scanning electron microscopy. After coloring, we notice that the particles are intact and have the same dimensions as before the coloration (Figures 1 and 2).

Claims

REVENDICATIONS
1. Particule possédant un cœur formé en tout ou partie d'au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, encapsulé dans une coquille formée d'au moins un polymère de mélamine-urée-formaldéhyde. A particle having a core formed in whole or in part of at least one polymer having a glass transition temperature of less than 75 ° C encapsulated in a shell of at least one melamine-urea-formaldehyde polymer.
2. Particule selon la revendication précédente, caractérisée en ce qu'elle est hydrodispersible.  2. Particle according to the preceding claim, characterized in that it is hydrodispersible.
3. Particule selon l'une quelconque des revendications précédentes, caractérisée en ce qu'elle possède une taille moyenne comprise entre 50 nm et 200 μπι, de préférence comprise entre 1 μηι et 20 μιη ou entre 50 nm et 200 nm.  3. Particle according to any one of the preceding claims, characterized in that it has a mean size of between 50 nm and 200 μπι, preferably between 1 μηι and 20 μιη or between 50 nm and 200 nm.
4. Particule selon l'une quelconque des revendications précédentes, caractérisée en ce que le rapport pondéral entre le polymère possédant une température de transition vitreuse inférieure à 75 °C et le polymère mélamine-urée-formaldéhyde varie de 1 % à 10 %.  4. Particle according to any one of the preceding claims, characterized in that the weight ratio between the polymer having a glass transition temperature of less than 75 ° C and the melamine-urea-formaldehyde polymer ranges from 1% to 10%.
5. Particule selon l'une quelconque des revendications précédentes, caractérisée en ce que le polymère formant en tout ou partie le cœur possède une température de transition vitreuse comprise entre 30 °C et 75 °C, de préférence comprise entre 30 °C et 50 °C.  5. Particle according to any one of the preceding claims, characterized in that the polymer forming all or part of the core has a glass transition temperature of between 30 ° C and 75 ° C, preferably between 30 ° C and 50 ° C. ° C.
6. Particule selon l'une quelconque des revendications précédentes, caractérisée en ce que le polymère formant en tout ou partie le cœur est choisi parmi les polyéthylènes glycol, les polyvinylpyrrolidones, les polyéthylméthacrylates, les dérivés d'alcools polyvinyliques, les polystyrènes, les latex, les polyéthylènes, les polypropylènes et leurs mélanges.  6. Particle according to any one of the preceding claims, characterized in that the polymer forming all or part of the core is selected from polyethylene glycol, polyvinylpyrrolidones, polyethylmethacrylates, derivatives of polyvinyl alcohols, polystyrenes, latexes polyethylenes, polypropylenes and mixtures thereof.
7. Particule selon l'une quelconque des revendications précédentes, caractérisée en ce que le polymère formant en tout ou partie le cœur est du polyéthylène glycol.  7. Particle according to any one of the preceding claims, characterized in that the polymer forming all or part of the core is polyethylene glycol.
8. Procédé de préparation de particules telles que définies selon l'une quelconque des revendications 1 à 7, caractérisé en ce qu'il comprend les étapes suivantes :  8. Process for the preparation of particles as defined according to any one of claims 1 to 7, characterized in that it comprises the following steps:
(i) disposer d'une phase organique contenant au moins un polymère possédant une température de transition vitreuse inférieure à 75 °C, à l'état de soluté, (ii) disposer d'une phase aqueuse contenant au moins les entités monomériques mélamine, urée, et formaldéhyde, destinées à former le polymère mélamine-urée- formaldéhyde (MUF), (i) having an organic phase containing at least one polymer having a glass transition temperature below 75 ° C, in the solute state, (ii) having an aqueous phase containing at least the melamine, urea, and formaldehyde monomeric entities for forming the melamine-urea-formaldehyde (MUF) polymer,
(iii) mettre en présence la phase organique et la phase aqueuse dans des conditions propices à la formation d'une émulsion de type phase organique dans phase aqueuse,  (iii) bringing the organic phase and the aqueous phase into contact under conditions conducive to the formation of an emulsion of organic phase type in aqueous phase,
(iv) réaliser un traitement thermique de l'émulsion pour activer et/ou stimuler la polymérisation des entités monomériques et former ainsi lesdites particules à écorce polymérique MUF et dont le cœur contient le polymère possédant une température de transition vitreuse inférieure à 75 °C, et  (iv) thermally treating the emulsion to activate and / or stimulate the polymerization of the monomeric entities and thereby form said MUF polymeric bark particles and whose core contains the polymer having a glass transition temperature below 75 ° C, and
(v) isoler lesdites particules.  (v) isolating said particles.
9. Procédé selon la revendication précédente, caractérisé en ce que le traitement thermique de l'étape (iv) consiste en un chauffage à une température comprise entre 28 °C et 100 °C, de préférence comprise entre 50 °C et 99 °C.  9. Method according to the preceding claim, characterized in that the heat treatment of step (iv) consists of heating at a temperature between 28 ° C and 100 ° C, preferably between 50 ° C and 99 ° C .
10. Procédé selon l'une quelconque des revendications 8 à 9, caractérisé en ce qu'il comprend en outre une étape (vi) de dialyse.  10. Method according to any one of claims 8 to 9, characterized in that it further comprises a step (vi) of dialysis.
11. Particule telle que définie selon l'une quelconque des revendications 1 à 7, caractérisée en ce qu'elle est en outre chargée en son cœur avec au moins une molécule d'intérêt.  11. Particle as defined in any one of claims 1 to 7, characterized in that it is further charged in its core with at least one molecule of interest.
12. Particule selon la revendication 11, caractérisée en ce que la molécule d'intérêt est un matériau de marquage et de préférence un marqueur optique.  12. Particle according to claim 11, characterized in that the molecule of interest is a marking material and preferably an optical marker.
13. Procédé pour charger une molécule d'intérêt au cœur d'une particule telle que définie selon l'une quelconque des revendications 1 à 7, caractérisé en ce qu'il comprend l'imprégnation de ladite particule en milieu C02 supercritique contenant une ou plusieurs molécule(s) d'intérêt. 13. Process for charging a molecule of interest in the core of a particle as defined in any one of claims 1 to 7, characterized in that it comprises impregnating said particle in a supercritical C0 2 medium containing a or more molecule (s) of interest.
14. Utilisation d'une particule selon la revendication 12 ou 13, comme outil de marquage.  14. Use of a particle according to claim 12 or 13 as a marking tool.
15. Matériau support comprenant au moins une particule selon la revendication 12 ou 13.  15. Support material comprising at least one particle according to claim 12 or 13.
16. Matériau selon la revendication 15, caractérisé en ce qu'il s'agit d'une encre ou d'un vernis.  16. Material according to claim 15, characterized in that it is an ink or a varnish.
PCT/IB2015/052049 2014-03-21 2015-03-20 Particles of melamine-urea-formaldehyde (muf) containing a polymer with a tg less than 75 °c. WO2015140764A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
FR1452381A FR3018701A1 (en) 2014-03-21 2014-03-21 MELAMINE-UREA-FORMALDEHYDE (MUF) PARTICLES CONTAINING A POLYMER HAVING A TG LESS THAN 75 ° C
FR1452381 2014-03-21

Publications (1)

Publication Number Publication Date
WO2015140764A1 true WO2015140764A1 (en) 2015-09-24

Family

ID=50877464

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2015/052049 WO2015140764A1 (en) 2014-03-21 2015-03-20 Particles of melamine-urea-formaldehyde (muf) containing a polymer with a tg less than 75 °c.

Country Status (2)

Country Link
FR (1) FR3018701A1 (en)
WO (1) WO2015140764A1 (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10537868B2 (en) 2015-07-02 2020-01-21 Givaudan S.A. Microcapsules
CN110918013A (en) * 2019-11-29 2020-03-27 武汉理工大学 Method for preparing microcapsules with random gradation

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3839064A (en) * 1972-09-21 1974-10-01 Champion Int Corp Inorganic pigment-loaded polymeric microcapsular system
KR910000711B1 (en) * 1988-07-06 1991-01-31 전주제지 주식회사 Preparation method of microcapsules
WO2002020683A2 (en) * 2000-09-06 2002-03-14 Appleton Papers Inc. In situ microencapsulated adhesive
WO2004048451A2 (en) 2002-11-26 2004-06-10 Genencor International, Inc. Optical information carrier comprising immobilized proteorhodopsin
US6863923B1 (en) 1999-09-29 2005-03-08 Institut Fuer Neue Materialien Gemeinnuetzige Gmbh Method and compositions for printing substrates
DE102007010109A1 (en) * 2007-02-28 2008-09-04 Henkel Ag & Co. Kgaa Particle forming carrier partially coated with a fine particulate active agent carrier matrix, useful e.g. in detergent composition and in a procedure for the fumigation of textiles
JP2009084527A (en) * 2007-10-03 2009-04-23 Mitsubishi Paper Mills Ltd Method for manufacturing heat accumulating microcapsule
US20100071882A1 (en) * 2008-09-25 2010-03-25 Eternal Chemical Co., Ltd. Natural microtubule encapsulated phase-change materials and preparation thereof
CN101724392A (en) * 2009-11-24 2010-06-09 张世智 Multiple reversible color change microcapsule anti-counterfeiting material and preparation method and application thereof
CN103231564A (en) * 2013-04-25 2013-08-07 天津工业大学 Preparation method of ultra-low-temperature protective material
KR20130103004A (en) * 2012-03-09 2013-09-23 금오공과대학교 산학협력단 Self-healing microcapsule, and method for preparing the same

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3839064A (en) * 1972-09-21 1974-10-01 Champion Int Corp Inorganic pigment-loaded polymeric microcapsular system
KR910000711B1 (en) * 1988-07-06 1991-01-31 전주제지 주식회사 Preparation method of microcapsules
US6863923B1 (en) 1999-09-29 2005-03-08 Institut Fuer Neue Materialien Gemeinnuetzige Gmbh Method and compositions for printing substrates
WO2002020683A2 (en) * 2000-09-06 2002-03-14 Appleton Papers Inc. In situ microencapsulated adhesive
WO2004048451A2 (en) 2002-11-26 2004-06-10 Genencor International, Inc. Optical information carrier comprising immobilized proteorhodopsin
DE102007010109A1 (en) * 2007-02-28 2008-09-04 Henkel Ag & Co. Kgaa Particle forming carrier partially coated with a fine particulate active agent carrier matrix, useful e.g. in detergent composition and in a procedure for the fumigation of textiles
JP2009084527A (en) * 2007-10-03 2009-04-23 Mitsubishi Paper Mills Ltd Method for manufacturing heat accumulating microcapsule
US20100071882A1 (en) * 2008-09-25 2010-03-25 Eternal Chemical Co., Ltd. Natural microtubule encapsulated phase-change materials and preparation thereof
CN101724392A (en) * 2009-11-24 2010-06-09 张世智 Multiple reversible color change microcapsule anti-counterfeiting material and preparation method and application thereof
KR20130103004A (en) * 2012-03-09 2013-09-23 금오공과대학교 산학협력단 Self-healing microcapsule, and method for preparing the same
CN103231564A (en) * 2013-04-25 2013-08-07 天津工业大学 Preparation method of ultra-low-temperature protective material

Non-Patent Citations (6)

* Cited by examiner, † Cited by third party
Title
DATABASE WPI Week 199232, Derwent World Patents Index; AN 1992-266040, XP002733235 *
DATABASE WPI Week 200930, Derwent World Patents Index; AN 2009-H35306, XP002733236 *
DATABASE WPI Week 201050, Derwent World Patents Index; AN 2010-H71720, XP002733234 *
DATABASE WPI Week 201425, Derwent World Patents Index; AN 2013-U22371, XP002733238 *
DATABASE WPI Week 201427, Derwent World Patents Index; AN 2013-Q02464, XP002733237 *
LIU, X, ET AL., MACROMOLECULAR MATERIALS AND ENGINEERING, vol. 294, 2009, pages 389 - 395

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10537868B2 (en) 2015-07-02 2020-01-21 Givaudan S.A. Microcapsules
CN110918013A (en) * 2019-11-29 2020-03-27 武汉理工大学 Method for preparing microcapsules with random gradation
CN110918013B (en) * 2019-11-29 2020-11-10 武汉理工大学 Method for preparing microcapsules with random gradation

Also Published As

Publication number Publication date
FR3018701A1 (en) 2015-09-25

Similar Documents

Publication Publication Date Title
WO2020229744A1 (en) Method for preparing biodegradable microcapsules and microcapsules obtained in this manner
EP2618927B1 (en) Process for manufacturing polysiloxane microcapsules that are functionalized and are not very porous.
EP2524011B1 (en) Method for coating with dispersions of active ingredients coated in a polymer layer
EP2762547B1 (en) Luminescent particles of carbon, method for preparing same and use thereof
WO2018100179A1 (en) Process for preparing microcapsules of controlled size comprising a photopolymerization step
FR2986324A1 (en) RESPECT INDICATOR OF A TEMPERATURE RANGE
JP2010539221A5 (en)
EP2883605A1 (en) Microcapsule-manufacturing process and microcapsules
US10821766B2 (en) Core-shell particle-based security pigment, and production method
EP3600642A1 (en) Method for preparing capsules with improved retention properties and capsules obtained therefrom
WO2015140764A1 (en) Particles of melamine-urea-formaldehyde (muf) containing a polymer with a tg less than 75 °c.
Kang et al. Strong response of multilayer polyelectrolyte films to cationic surfactants
FR2501059A1 (en) PROCESS FOR OBTAINING ISODIAMETRAL MICROCAPSULES WITH REGULATED DIAMETER
CA2876352C (en) Heat-stable particulate ink for inkjet use
WO2018172360A1 (en) Method for preparing capsules comprising at least one water-soluble or hydrophilic substance and capsules obtained therefrom
FR3116213A1 (en) METHOD FOR THE PREPARATION OF BIODEGRADABLE MICROCAPSULES AND USE OF THE MICROCAPSULES THUS OBTAINED
EP4010110A1 (en) Method for manufacturing microcapsules containing a lipophilic active ingredient, microcapsules prepared by said method and the use thereof
WO2015140749A1 (en) Particles of melamine-urea-formaldehyde (muf) containing an optical marker with adjustable chromatic effect
WO2018100196A1 (en) Method for preparing microcapsules and microparticles of controlled size
EP2391631B1 (en) Novel material with spin transition, and method for making same
EP0728786B1 (en) Composition useful for lacquers based on mixtures of emulsions and dispersions of polymers and coatings prepared therefrom
WO2019145416A1 (en) Hair coloring composition comprising microcapsules
BE741741A (en) Microencapsulation
BE829482R (en) PROCESS FOR PRODUCING MICROCAPSULES AND MICROCAPSULES THUS OBTAINED
WO2014170567A1 (en) Luminescent inorganic core/shell particle, production method and use

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 15715450

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 15715450

Country of ref document: EP

Kind code of ref document: A1