EP1660415A2 - Utilisation de particules a noyau et enveloppe - Google Patents

Utilisation de particules a noyau et enveloppe

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Publication number
EP1660415A2
EP1660415A2 EP04763795A EP04763795A EP1660415A2 EP 1660415 A2 EP1660415 A2 EP 1660415A2 EP 04763795 A EP04763795 A EP 04763795A EP 04763795 A EP04763795 A EP 04763795A EP 1660415 A2 EP1660415 A2 EP 1660415A2
Authority
EP
European Patent Office
Prior art keywords
core
poly
shell
shell particles
copolymers
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP04763795A
Other languages
German (de)
English (en)
Inventor
Holger Winkler
Rene Schneider
Goetz Peter Hellmann
Tilmann Eberhard Ruhl
Peter Spahn
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Merck Patent GmbH
Original Assignee
Merck Patent GmbH
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
Priority claimed from DE2003141198 external-priority patent/DE10341198A1/de
Priority claimed from DE2003157680 external-priority patent/DE10357680A1/de
Application filed by Merck Patent GmbH filed Critical Merck Patent GmbH
Publication of EP1660415A2 publication Critical patent/EP1660415A2/fr
Withdrawn legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B20/00—Use of materials as fillers for mortars, concrete or artificial stone according to more than one of groups C04B14/00 - C04B18/00 and characterised by shape or grain distribution; Treatment of materials according to more than one of the groups C04B14/00 - C04B18/00 specially adapted to enhance their filling properties in mortars, concrete or artificial stone; Expanding or defibrillating materials
    • C04B20/10—Coating or impregnating
    • C04B20/12—Multiple coating or impregnating
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B82—NANOTECHNOLOGY
    • B82Y—SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES
    • B82Y30/00—Nanotechnology for materials or surface science, e.g. nanocomposites
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B38/00—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof
    • C04B38/04—Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof by dissolving-out added substances
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
    • C08K9/00—Use of pretreated ingredients
    • C08K9/08—Ingredients agglomerated by treatment with a binding agent
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B2111/00—Mortars, concrete or artificial stone or mixtures to prepare them, characterised by specific function, property or use
    • C04B2111/00034—Physico-chemical characteristics of the mixtures
    • C04B2111/00129—Extrudable mixtures
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/24—Structurally defined web or sheet [e.g., overall dimension, etc.]
    • Y10T428/24355—Continuous and nonuniform or irregular surface on layer or component [e.g., roofing, etc.]

Definitions

  • the invention relates to the use of core-shell particles for the production of moldings with homogeneous, regularly arranged cavities, a process for the production of moldings with homogeneous, regularly arranged cavities and the corresponding moldings.
  • Shaped bodies with homogeneous, regularly arranged cavities in the sense of the present invention are materials which have three-dimensional photonic structures.
  • three-dimensional photonic structures i. a. Systems understood that have a regular, three-dimensional modulation of the dielectric constant (and therefore also the refractive index). If the periodic modulation length corresponds approximately to the wavelength of the (visible) light, the structure interacts with the light in the manner of a three-dimensional diffraction grating, which manifests itself in angle-dependent color phenomena.
  • An example of this is the naturally occurring gemstone opal, which consists of a densely packed ball packing made of silicon dioxide balls and cavities in between, which are filled with air or water.
  • Three-dimensional inverse structures can be created by template synthesis:
  • Capillary effects are filled with a gaseous or liquid precursor or a solution of a precursor.
  • SiO 2 spheres can be arranged in the densest packing, the hollow volumes are filled with solutions containing tetraethyl orthotitanate. After several tempering steps, are in an etching process
  • De La Rue et al. (De La Rue et al. Synth. Metals, 2001, 116, 469) describe the production of inverse, consisting of TiO opals according to the following method: A dispersion of 400 nm in size
  • Polystyrene balls are dried on a filter paper under an IR lamp.
  • the filter cake is suctioned off with ethanol, transferred to a glove box and infiltrated with tetraethyl orthotitanate using a water jet pump.
  • the calcination takes place in the tube furnace at 575 ° C. for 8 hours in an air stream, whereby titanium dioxide is formed from the ethoxide and the latex particles are burned out.
  • An inverse TiO 2 opal structure remains.
  • Martinelli et al. (M. Martinelli et al. Optical Mater. 2001, 17, 11) describe the production of inverse TiO 2 opals using 780 nm and 3190 nm large polystyrene balls.
  • a regular arrangement in the densest spherical packing is achieved by centrifuging the aqueous spherical dispersion at 700-1000 rpm for 24-48 hours and then decanting, followed by air drying.
  • the regularly arranged balls are moistened with ethanol on a filter on a Buchner funnel and then dropwise provided with an ethanolic solution of tetraethyl orthotitanate.
  • the sample is dried in a vacuum desiccator for 4 to 12 hours. This filling procedure is repeated 4 to 5 times.
  • the polystyrene balls are then burned out at 600 ° C - 800 ° C for 8 - 10 hours.
  • Stein et al. (A. Stein et al. Science, 1998, 281, 538) describe the synthesis of inverse TiO 2 opals from polystyrene spheres with a diameter of 470 nm as a template. These are made in a 28 hour process, subjected to centrifugation and air dried. Then the latices template are applied to a filter paper.
  • Ethanol is sucked into the latex template via a Büchner funnel, which is connected to a vacuum pump. Then tetraethyl orthotitanate is added dropwise with suction. After drying in a vacuum desiccator for 24 h, the latices are burned out at 575 ° C for 12 h in an air stream.
  • Vos et al. (WL Vos et al. Science, 1998, 281, 802) produce inverse TiO 2 opals by using polystyrene spheres with diameters of 180-1460 nm as templates.
  • a sedimentation technique is used to set the densest spherical packing of the spheres, which is supported by centrifugation for up to 48 h.
  • an ethanolic solution of tetra-n-propoxy orthotitanate is added to it in a glove box.
  • the infiltrated material is brought into the air to allow the precursor to react to form TiO 2 . This procedure is repeated eight times to ensure complete filling with TiO 2 .
  • the material is then calcined at 450 ° C.
  • Core-shell particles the shell of which forms a matrix and whose core is essentially solid and has an essentially monodisperse size distribution, are described in German patent application DE-A-10145450.
  • the use of such core-shell particles, the shell of which forms a matrix and whose core is essentially solid and has an essentially monodisperse size distribution as a template for the production of inverse opal structures and a method for the production of inverse opal-like structures using such core-shell particles is described in the older German patent application DE 10245848.0.
  • the moldings described with homogeneous, regularly arranged cavities i.e. inverse opal structure
  • a first object of the present invention is therefore the use of core-shell particles whose shell forms a matrix and whose core is essentially solid and has an essentially monodisperse size distribution and whose shell is connected to the core via an intermediate layer and whose shell is thermoplastic Has properties for the production of moldings with homogeneous, regularly arranged cavities.
  • thermoplastic properties are understood to mean that the corresponding materials have one Have flow transition area above room temperature.
  • those materials are meant here which are referred to as thermoplastics in accordance with DIN 7724, TI.2, the materials which have an energy-elastic behavior at room temperature - that is to say the thermoplastics in the narrower sense - being among the preferred materials.
  • Another object of the present invention is a method for producing moldings with homogeneous, regularly arranged cavities, characterized in that core-shell particles, the shell of which forms a matrix and whose core is essentially solid and has an essentially monodisperse size distribution and is connected to the core via an intermediate layer and the jacket of which has thermoplastic properties, is processed into shaped bodies, preferably films, using a mechanical force and elevated temperature, and the cores are subsequently removed.
  • the templates can be processed via melting processes.
  • the matrix m. preferably made of poly (styrene), thermoplastic poly (acrylate) derivatives, preferably poly (methyl methacrylate) or poly (cyciohexyl methacrylate), or thermoplastic copolymers of these polymers with other acrylates, such as preferably styrene-acrylonitrile copolymers, styrene-ethyl acrylate copolymers or Methyl methacrylate-ethyl acrylate) - n copolymers is built up.
  • “Built up” in the sense of the present invention means that the materials are contained in such a large amount that the material properties of the shaped bodies are dominated by these polymers.
  • the shaped bodies can also contain other constituents, in particular processing aids, in amounts of up to contain 50 wt .-%.
  • the core-shell particles In order to achieve the optical or photonic effect according to the invention, it is desirable for the core-shell particles to have an average particle diameter in the range from about 5 nm to about 2000 nm. It can be particularly preferred if the core-shell particles have an average particle diameter in the range from about 5 to 20 nm, preferably 5 to 10 nm. In this case the nuclei can be called "quantum dots"; they show the corresponding effects known from the literature. To achieve color effects in the visible light range, it is particularly advantageous if the core-shell particles have an average particle diameter in the range of approximately 50-800 nm.
  • Particles in the range from 100 to 600 nm and very particularly preferably in the range from 200 to 450 nm are particularly preferably used, since with particles in this order of magnitude (depending on the refractive index contrast which can be achieved in the photonic structure) the reflections of different wavelengths of visible light become clear distinguish from each other and so the opalescence, which is particularly important for optical effects in the visible range, occurs particularly distinctly in a wide variety of colors. In a variant of the present invention, however, it is also preferred to use multiples of this preferred particle size, which then lead to reflections corresponding to the higher orders and thus to a broad play of colors.
  • the cavities of the shaped bodies according to the invention then each have corresponding average diameters, which are approximately identical to the diameter of the cores. With preferred core-shell ratios of the particles, the cavity diameter thus corresponds to approximately 2/3 of the core-shell particle diameter. It is particularly preferred according to the invention if the mean diameter of the cavities is in the range from about 50 to 500 nm, preferably in the range from 100 to 500 nm and very particularly preferably in the range from 200 to 280 nm.
  • the intermediate layer is a layer of crosslinked or at least partially crosslinked polymers.
  • the interlayer can be crosslinked via free radicals, for example induced by UV radiation, or preferably via di- or oligofunctional monomers.
  • Preferred intermediate layers of this embodiment contain 0.01 to 100% by weight, particularly preferably 0.25 to 10 % By weight, di- or oligo-functional monomers.
  • Preferred di- or oligo-functional monomers are in particular isoprene and allyl methacrylate (ALMA).
  • AMA allyl methacrylate
  • Such an intermediate layer of crosslinked or at least partially crosslinked polymers preferably has a thickness in the range of
  • Refractive index of the layer chosen so that it corresponds either to the refractive index of the core or the refractive index of the cladding.
  • copolymers are used as the intermediate layer which, as described above, contain a crosslinkable monomer
  • the person skilled in the art will have no problem in selecting suitable copolymerizable monomers in a suitable manner.
  • corresponding copolymerizable monomers can be selected from a so-called Q-e scheme (cf. textbooks of macromolecular chemistry).
  • Monomers such as methyl methacrylate and methyl acrylate can preferably be polymerized with ALMA.
  • shell polymers are grafted directly onto the core via a corresponding functionalization of the core.
  • the surface functionalization of the core forms the intermediate layer according to the invention.
  • the type of surface functionalization depends mainly on the material of the core.
  • Silicon dioxide surfaces can, for example, advantageously be suitably modified with silanes which carry correspondingly reactive end groups, such as epoxy functions or free double bonds.
  • the monodisperse cores are dispersed in alcohols and modified with common organoalkoxysilanes.
  • the silanization of spherical oxide particles is also described in DE 43 16 814. Such silanization improves the dispersibility of inorganic
  • the shell of these core-shell particles consists of essentially uncrosslinked organic polymers which are preferably grafted onto the core via an at least partially crosslinked intermediate layer.
  • the core can consist of various materials. It is only essential in the sense of the present invention that the cores can be removed under conditions in which the wall material is stable. The selection of suitable core / cladding / interlayer wall material combinations does not pose any difficulties for the person skilled in the art.
  • the core of the core-shell particles consists of a material which either does not flow or becomes flowable at a temperature above the flow temperature of the shell material.
  • This can be achieved by using polymeric materials with a correspondingly high glass transition temperature (T g ), preferably crosslinked polymers, or by using inorganic core materials.
  • T g glass transition temperature
  • the suitable materials are described in detail below.
  • the cores are composed of an inorganic material, preferably a metal or semimetal or a metal chalcogenide or metal pnictide.
  • chalcogenides are compounds in which an element of the 16th group of the periodic table is the electronegative binding partner; as Pnictide those in which an element of the 15th group of the
  • Periodic table is the electronegative binding partner.
  • Cores consist of metal chalcogenides, preferably metal oxides, or metal pnictides, preferably nitrides or phosphides.
  • Counterions can occur as electropositive partners, such as the classic metals of the subgroups or the main group metals of the first and second main groups, but also all elements of the third main group, as well as silicon, germanium, tin, lead, phosphorus, arsenic, antimony and bismuth.
  • the preferred metal chalcogenides and metal pnictides include in particular silicon dioxide, aluminum oxide, gallium nitride, boron and aluminum nitride as well as silicon and phosphorus nitride.
  • monodisperse silicon dioxide cores are preferably used as the starting material for the production of the core-shell particles to be used according to the invention, which can be obtained, for example, by the process described in US Pat. No. 4,911,903.
  • the cores are produced by hydrolytic polycondensation of tetraalkoxysilanes in an aqueous-ammoniacal medium, whereby a sol of primary particles is first produced and then the SiO 2 particles obtained are brought to the desired particle size by continuous, controlled metering in of tetraalkoxysilane. This method can be used to produce monodisperse SiO 2 cores with average particle diameters between 0.05 and 10 ⁇ m with a standard deviation of 5%.
  • Monodisperse cores made of non-absorbent metal oxides such as TiO 2 , ZrO 2 , ZnO 2 , SnO 2 or Al 2 O 3 or metal oxide mixtures can also be used as the starting material. Their manufacture is described for example in EP 0 644 914. Furthermore, the method according to EP 0 216 278 for producing monodisperse SiO 2 cores is straightforward and easy same result transferable to other oxides. To a mixture of
  • Thermostats are set exactly to 30 to 40 ° C, with intensive mixing tetraethoxysilane, tetrabutoxytitanium, tetrapropoxy-zirconium or mixtures thereof are added in one pour and the mixture obtained is stirred intensively for a further 20 seconds, with a suspension of monodisperse cores in the Forms nanometer range. After a post-reaction time of 1 to 2 hours, the cores are removed in the usual way, e.g. by centrifugation, separated, washed and dried.
  • the core in the core-shell particles consists essentially of a material which can be degraded with UV radiation, preferably a UV-degradable organic polymer and particularly preferably poly (tert-butyl methacrylate), poly ( methyl methacrylate), poly (n-butyl methacrylate) or copolymers containing one of these polymers.
  • the wall of the molded body with homogeneous, regularly arranged cavities is formed from the polymers of the shell of the core-shell particles. 5
  • a mechanical strength of the core-shell particles Q is formed a "positive" opal structure as a template in a first step by application.
  • the mechanical action of force can, according to the invention, be such a force action that occurs in the usual processing steps of polymers.
  • the mechanical force is applied either: by uniaxial pressing or
  • the shaped bodies according to the invention are preferably films.
  • Films according to the invention can preferably also be produced by calendering, film blowing or flat film extrusion.
  • the various possibilities of processing polymers under the influence of mechanical forces are well known to the person skilled in the art and can be found, for example, in the standard textbook Adolf Franck, "Plastic Compendium”; Vogel-Verlag; 1996 are taken.
  • the processing of core-shell particles by the action of mechanical force, as is preferred here, is also described in detail in the international patent application WO 2003025035.
  • the temperature during production is at least 40 ° C, preferably at least 60 ° C above the glass point of the shell of the core-shell particles. It has been shown empirically that the
  • the flowable core-shell particles are cooled under the action of the mechanical force to a temperature at which the shell is no longer flowable.
  • the demolding takes place only after the mold with the molding contained therein has cooled.
  • molds with a large cooling channel cross section are used, since the cooling can then take place in a shorter time. It has been shown that the color effects according to the invention become significantly more intense as a result of the cooling in the mold. It is assumed that this uniform cooling process leads to a better arrangement of the core-shell particles with the lattice. It is particularly advantageous if the mold was heated before the injection process.
  • the moldings according to the invention can, if it is technically advantageous, contain auxiliaries and additives. They can be used to optimally set the application data or properties desired or required for application and processing.
  • auxiliaries and / or additives are antioxidants, UV stabilizers, biocides, plasticizers, film-forming aids, leveling agents, fillers, melting aids, adhesives, release agents, application aids, mold release agents, agents for viscosity modification, for. B. thickener.
  • the number n can vary within the chain and the various chain links can be built in in a statistical or block-wise distribution.
  • auxiliaries are ethylene glycol, propylene glycol, di-, tri- and tetraethylene glycol, di-, tri- and tetrapropylene glycol, polyethylene oxides, polypropylene oxide and ethylene oxide / propylene oxide mixed polymers with molecular weights of up to approx. 15000 and statistical or block-like distribution of the ethylene oxide and propylene oxide assemblies.
  • organic or inorganic solvents, dispersants or diluents are also available, for example the open time of the formulation, ie the time for their application to substrates standing time, extend waxes or hot melt adhesive as additives possible.
  • z. B derivatives of 2,4-dihydroxybenzophenone, derivatives of 2-cyan-3,3'-dephenyl acrylate, derivatives of 2,2 ', 4,4 , -tetrahydroxybenzophenone, derivatives of o-hydroxyphenyl-benzotriazole, salicylic acid esters, o-hydroxyphenyl -s-triazines or sterically hindered amines. These substances can also be used individually or as mixtures.
  • the total amount of auxiliaries and / or additives is up to 40% by weight, preferably up to 20% by weight, particularly preferably up to 5% by weight, of the weight of the moldings.
  • the cores can be removed in various ways. If the cores are made of suitable inorganic materials, they can be removed by etching. For example, silicon dioxide cores can preferably be removed with HF, in particular dilute HF solution. With this procedure, it can again be preferred if, before or after the removal of the cores, the jacket is crosslinked, as described above. In this case, the jacket and thus the matrix of the molded body are given thermosetting properties.
  • the cores in the core-shell particles are made of a UV-degradable material, preferably a UV-degradable organic polymer, the cores are removed by UV radiation. In this procedure, too, it can in turn be preferred if, before or after the removal of the cores, the jacket is crosslinked, as described above.
  • Impregnation can consist, for example, of storing liquid crystals, as described, for example, in Ozaki et al., Adv. Mater. 2002, 14, 514 and Sato et al., J. Am. Chem. Soc. 2002, 124, 10950.
  • the impregnation with such or other materials allows the optical, electrical, acoustic and mechanical properties to be influenced by external energy fields.
  • optical, electrical, acoustic and mechanical properties can be influenced by external energy fields.
  • Electro-optical devices based on liquid crystals are well known to the person skilled in the art and can be based on various effects. Such devices are, for example, cells with dynamic scattering, DAP cells (deformation of aligned phases), guest host cells, TN cells with twisted nematic ("twisted nematic")
  • STN cells super-twisted nematic
  • SBE cells
  • the most common display devices are based on the
  • the corresponding liquid crystal materials must have good chemical and thermal stability and good stability against electric fields and electromagnetic radiation. Furthermore, the liquid crystal materials should have low viscosity and in give the cells short response times, low threshold voltages and a high contrast.
  • Such matrix liquid crystal displays are known.
  • active elements i.e. transistors
  • non-linear elements for the individual switching of the individual pixels.
  • MOS Metal Oxide Semiconductor
  • TFT Thin film transistors
  • the TN effect is usually used as the electro-optical effect.
  • TFTs based on polycrystalline or amorphous silicon are being worked on with great intensity worldwide.
  • the TFT matrix is applied to the inside of one glass plate of the display, while the other glass plate carries the transparent counter electrode on the inside. Compared to the size of the pixel electrode, the TFT is very small and practically does not disturb the image.
  • This technology can also be expanded for fully color-compatible image representations, with a mosaic of red, green and blue filters being arranged in such a way that one filter element each is opposite a switchable image element.
  • the TFT displays usually work as TN cells with crossed polarizers in transmission and are illuminated from behind.
  • MLC displays of this type are particularly suitable for TV applications (for example pocket TVs) or for high-information displays for computer applications (laptops) and in automobile or aircraft construction.
  • TV applications for example pocket TVs
  • high-information displays for computer applications (laptops) and in automobile or aircraft construction.
  • the contrast of an MLC display deteriorates and the problem of "after image elimination” can occur.
  • the resistivity of the liquid crystal mixture generally decreases over the lifetime of an MLC display due to interaction with the inner surfaces of the display, a high (initial) resistance is very important in order to obtain acceptable service lives.
  • the moldings according to the invention can in principle be used in combination with suitable liquid crystal mixtures which are known to the person skilled in the art in electro-optical displays based on all the principles described, in particular for MFK, IPS, TN or STN displays.
  • the shaped bodies obtainable according to the invention with homogeneous, regularly arranged cavities are suitable on the one hand for the use described above as photonic material, preferably with the impregnation mentioned, but on the other hand also for the production of porous surfaces, membranes, separators, filters and porous supports. These materials can also be used, for example, as fluidized beds in fluidized bed reactors.
  • the shell of the core-shell particles according to the invention contains one or more polymers and / or copolymers or polymer precursors and, if appropriate, auxiliaries and additives, the composition of the shell being able to be selected such that it in non-swelling environment at room temperature is essentially dimensionally stable and tack-free.
  • Polymers that meet the specifications for a sheath material can also be found in the groups of polymers and copolymers of polymerizable unsaturated monomers, as well as the polycondensates and copolycondensates of monomers with at least two reactive groups, such as, for. B. the high molecular weight aliphatic, aliphatic / aromatic or fully aromatic polyesters and polyamides.
  • Some other examples may illustrate the wide range of polymers suitable for making the sheath.
  • sheath is to have a comparatively low refractive index
  • polymers such as polyacrylates, polymethacrylates, polybutadiene, polymethyl methacrylate, polyesters, polyamides and polyacrylonitrile are suitable, for example.
  • polymers with a preferably aromatic basic structure such as polystyrene, polystyrene copolymers such as. B. SAN, aromatic-aliphatic polyesters and polyamides, aromatic polysulfones and polyketones, and with a suitable choice of a high-index core material also polyacrylonitrile.
  • the weight ratio of core to shell is in the range from 5: 1 to 1:10, in particular in the range from 2: 1 to 1: 5 and particularly preferred is in the range 1, 5: 1 to 1: 2.
  • the core-shell particles which can be used according to the invention can be produced by various processes.
  • a preferred way of obtaining the particles is a process for the production of core-shell particles, by a) surface treatment of monodisperse cores, and b) application of the shell from organic polymers to the treated cores.
  • a crosslinked polymeric intermediate layer is applied to the cores, preferably by emulsion polymerization or by ATR polymerization, which preferably has reactive centers to which the jacket can be covalently attached.
  • ATR-Polymerization stands here for Atomic Transfer Radicalic Polymerization, as for example in K. Matyjaszewski, Practical Atom Transfer Radical Polymerization, Polym. Mater. Be. Closely. 2001, 84. Encapsulation of inorganic materials using ATRP is described, for example, in T.
  • Emulsion polymerizations are familiar to the person skilled in the art of polymer production and are described, for example, in the abovementioned. References described.
  • the liquid reaction medium in which the polymerizations or copolymerizations can be carried out consists of those used in polymerizations, in particular in processes of the emulsion
  • Aqueous media in particular water, are favorable as a liquid reaction medium for carrying out the process according to the invention.
  • polymerization initiators are suitable which either decompose thermally or photochemically, form radicals, and thus initiate the polymerization.
  • thermally activatable polymerization initiators preference is given to those which decompose between 20 and 180 ° C., in particular between 20 and 80 ° C.
  • Particularly preferred polymerization initiators are 5 peroxides, such as dibenzoyl peroxide, di-tert-butyl peroxide, peresters, percarbonates, perketals, hydroperoxides, but also inorganic peroxides, such as H 2 O 2 , salts of peroxosulfuric acid and peroxodisulfuric acid, azo compounds, boron compounds and 0 homolytically decomposing hydrocarbons ,
  • the initiators and / or photoinitiators which, depending on the requirements for the polymerized material, are used in amounts between 0.01 and 15% by weight, based on the polymerizable components, can be used individually or, in order to take advantage of advantageous synergistic effects, in combination 5 applied with each other.
  • Redox systems are also used Application, such as salts of peroxodisulfuric acid and peroxosulfuric acid in combination with low-valent sulfur compounds, in particular ammonium peroxodisulfate in combination with sodium dithi
  • Polyaddition products are obtained analogously by reaction with compounds which have at least two, preferably three reactive groups, such as, for. B. epoxy, cyanate, isocyanate, or isothiocyanate groups, with compounds that carry complementary reactive groups.
  • reactive groups such as, for. B. epoxy, cyanate, isocyanate, or isothiocyanate groups
  • isocyanates react with alcohols to form urethanes, with amines to form urea derivatives, while epoxides react with these complementaries to form hydroxyethers or hydroxyamines.
  • polyaddition reactions can advantageously also be carried out in an inert solvent or dispersant.
  • Dispersing aids are generally used to prepare the stable dispersions required for these polymerization-polycondensation or polyaddition processes.
  • Dispersing aids are preferably water-soluble, high molecular weight organic compounds with polar groups, such as polyvinyl pyrrolidone, copolymers of vinyl propionate or acetate and vinyl pyrrolidone, partially saponified copolymer list of an acrylic ester and acrylonitrile, polyvinyl alcohols with different residual acetate content, cellulose ethers, Gelatin, block copolymers, modified starch, low molecular weight, carbon and / or sulfonic acid group-containing polymers or mixtures of these substances are used.
  • polar groups such as polyvinyl pyrrolidone, copolymers of vinyl propionate or acetate and vinyl pyrrolidone, partially saponified copolymer list of an acrylic ester and acrylonitrile, polyvinyl alcohols with different residual acetate content, cellulose ethers, Gelatin, block copolymers, modified starch, low molecular weight, carbon and / or sulfonic
  • Particularly preferred protective colloids are polyvinyl alcohols with a residual acetate content of less than 35, in particular 5 to 39 mol% and / or vinylpyrrolidone-oleyl propionate copolymers with a vinyl ester content of less than 35, in particular 5 to 30% by weight.
  • Nonionic or ionic emulsifiers can be used.
  • Preferred emulsifiers are, where appropriate, ethoxylated or propoxylated, longer-chain alkanols or alkylphenols with different degrees of ethoxylation or propoxylation (eg adducts with 0 to 50 mol of alkylene oxide) or their neutralized, sulfated, sulfonated or phosphated derivatives.
  • Neutralized dialkylsulfosuccinic acid esters or alkyldiphenyloxide disulfonates are also particularly suitable.
  • Dispersions can be obtained.
  • the particle size can be set, for example, via the selection and amount of the initiators and other parameters, such as the reaction temperature.
  • the appropriate setting of these parameters does not pose any difficulties for the person skilled in the field of polymerization.
  • Monomers which lead to polymers with a high refractive index are generally those which either have aromatic partial structures or those which have heteroatoms with a high atomic number, such as, for example, B. halogen atoms, especially bromine or iodine atoms, sulfur or metal ions, that is, atoms or groupings of atoms which increase the polarizability of the polymers.
  • Polymers with a low refractive index are accordingly obtained from monomers or monomer mixtures which do not contain the mentioned partial structures and / or atoms with a high atomic number or only in a small proportion.
  • Phenyl methacrylate and benzyl (meth) acrylate.
  • the refractive index of polymers can also be increased by polymerizing mono- containing carboxylic acid groups erer and transfer of the "acidic" polymers thus obtained into the corresponding salts with metals of higher atomic weight, such as. B. preferably with K, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Co, Cr, Cu, Mn, Sn or Cd.
  • Refractive index of the polymers produced therefrom can be homopolymerized or copolymerized with one another. They can also be copolymerized with a certain proportion of monomers that make a lower contribution to the refractive index. Such copolymerizable monomers with a lower refractive index contribution are, for example, acrylates, methacrylates, vinyl ethers or vinyl esters with purely aliphatic radicals.
  • bifunctional or polyfunctional compounds which can be copolymerized with the monomers mentioned above or which can subsequently react with the polymers with crosslinking can also be used as crosslinking agents for producing crosslinked matrix materials.
  • Group 1 bisacrylates, bismethacrylates and bisvinyl ethers of aromatic or aliphatic di- or polyhydroxy compounds, in particular of butanediol (butanediol-di (meth) acrylate, butanediol-bis-vinyl ether), hexanediol (hexanediol-di (meth) acrylate, hexanediol-bis- vinyl ether), pentaerythritol, hydroquinone, bis-hydroxyphenylmethane, bis-hydroxyphenyl ether, bis-hydroxymethyl-benzene, bisphenol A or with ethylene oxide spacers, propylene oxide spacers, or mixed ethylene oxide-propylene oxide spacers.
  • butanediol butanediol-di (meth) acrylate, butanediol-bis-vinyl ether
  • hexanediol
  • crosslinkers in this group are e.g. B. di- or polyvinyl compounds, such as divinybenzene, or also methylene-bisacrylamide, triallyl cyanurate, divinylethylene urea, trimethylolpropane tri- (meth) acrylate, trimethylolpropane tricinyl ether, pentaerythritol tetra (meth) acrylate, pentaerythritol tetra vinyl ethers, and crosslinkers with two or more different reactive ends, such as.
  • Group 2 reactive crosslinking agents which have a crosslinking action, but mostly have a postcrosslinking action, e.g. B. with heating or drying, and which are copolymerized into the core or shell polymers as copolymers.
  • Examples include: N-methylol- (meth) acrylamide, acrylamidoglycolic acid, and their ethers and / or esters with C 1 to C 6 alcohols, diacetone acrylamide (DAAM), glycidyl methacrylate (GMA), methacryloyloxypropyltrimethoxysilane (MEMO), vinyl trimethoxysilane, m-isopropenyl benzyl isocyanate (TMI).
  • DAAM diacetone acrylamide
  • GMA glycidyl methacrylate
  • MEMO methacryloyloxypropyltrimethoxysilane
  • TMI m-isopropenyl benzyl isocyanate
  • Group 3 Carboxylic acid groups which have been incorporated into the polymer by copolymerization of unsaturated carboxylic acids are crosslinked like polyvalent metal ions. Acrylic acid, methacrylic acid, maleic anhydride, itaconic acid and fumaric acid are preferably used as unsaturated carboxylic acids for this purpose. Mg, Ca, Sr, Ba, Zn, Pb, Fe, Ni, Co, Cr, Cu, Mn, Sn, Cd are suitable as metal ions. Ca, Mg and Zn, Ti and Zr are particularly preferred. Monovalent metal ions, such as Na or K, are also suitable.
  • Group 4 Post-crosslinked additives. This is understood to mean additives which are functionalized to a degree or higher and which react irreversibly with the polymer (by addition or preferably condensation reactions) to form a network. Examples of this are compounds that are per
  • Molecule have at least two of the following reactive groups: epoxy, aziridine, isocyanate acid chloride, carbodiimide or carbonyl groups, further z.
  • post-crosslinkers with reactive groups such as, for. B. epoxy and isocyanate groups, complementary, reactive groups in the polymer to be crosslinked.
  • reactive groups such as, for. B. epoxy and isocyanate groups
  • isocyanates react with alcohols to form urethanes, with amines to form urea derivatives, while epoxides react with these complementary groups to form hydroxyethers or hydroxyamines.
  • Post-crosslinking is also understood to mean photochemical curing, an oxidative, or an air- or moisture-induced curing of the systems.
  • the monomers and crosslinking agents mentioned above can be combined with one another in a targeted manner and (co) polymerized, so that an optionally crosslinked (co) polymer is obtained with the desired refractive index and the required stability criteria and mechanical properties.
  • the coating of organic polymers is applied by grafting, preferably by emulsion polymerization or ATR polymerization. The methods and monomers described above can be used accordingly.
  • the SiO 2 cores are produced by hydrolysis and condensation of TEOS in a solution of water, ammonia and ethanol using a modified Stöber process.
  • First seed particles are produced, which are then enlarged in a step process.
  • 500 ml of ethanol and 25 ml of ammonia solution (25% by weight) are placed in a 2 round-bottom flask with a water bath, magnetic stirrer and pressure compensation. After the reaction temperature of 35 ° C has been reached, 19 ml of TEOS are quickly injected. After stirring for 2.5 h, the particles are enlarged by adding 4 ml of ammonia solution and injecting 15 mH TEOS. The reaction is stirred for a further 4 h.
  • the suspension formed contains 0.69 M NH 3 , 2 MH 2 O and 2.5% by weight SiO 2 .
  • the seed particles are gradually enlarged.
  • the suspension is diluted with ethanol and ammonia solution such that the concentration of SiO 2 was 0.5% by weight before each reaction step and 2.5% by weight after the reaction step.
  • the concentrations of ammonia and water are kept constant at 0.69 M NH 3 and 2 MH 2 O.
  • 265 ml of SiO 2 suspension are placed in a 2 l round-bottom flask with water bath, magnetic stirrer and pressure equalization and diluted with 165.5 ml of ethanol and 9.5 ml of ammonia solution (25% by weight). After the reaction temperature of 35 ° C has been reached, 13 ml of TEOS are quickly injected. The reaction is stirred for at least 4 h.
  • the next reaction step can be carried out directly afterwards or after cooling and storing the suspension for several days.
  • reaction solution is concentrated to 300 ml and transferred to a 1 liter round bottom flask. 0.06 g of SDS, dissolved in 120 g of water, are added and ethanol is distilled off again at 65.degree. The distilled liquid is replaced by water.
  • Example 1 The other samples from Example 1 are implemented analogously.
  • the emulsion polymerization is carried out in a double-walled, 250 ml glass reactor thermostatted to 75 ° C. with an inert gas feed, propeller stirrer and reflux condenser.
  • 110 g (contain 17 g SiO 2 ) SiO 2 suspension according to Example 2 are argon for 20 min
  • MMA, 0.6 g ALMA, 0.02 g SDS (0.33% by weight on monomer), 0.04 g KOH and 30 g water were metered in continuously over a period of 90 min.
  • the reactor contents are stirred for 20 minutes without further addition. Then 0.02 g of APS was added, dissolved in 3 g of water. After 10 minutes, a second monomer emulsion of 20 g of CHMA, 0.08 g SDS (0.4 wt .-% on monomer) and 40 g of water over a period of 200 min ⁇ 0 u kontinuieriich added. For almost complete reaction of the monomers, the mixture is then stirred for a further 120 min. The core-shell particles are then precipitated in 500 ml of ethanol, the precipitation is completed by adding 15 g of concentrated aqueous saline solution 5, the suspension with 500 ml of dist. Water is added, suction filtered and the polymer is dried at 50 ° C. in vacuo.
  • the dried, powdery polymers from Example 3 are granulated in an extruder (microextruder from DSM Research) at 200 ° C.
  • the granules are heated 5 in a hydraulic press (Collin 300 P) and pressed at a predetermined hydraulic pressure.
  • Flat metal sheets covered with PET film are used as the mold.
  • a typical press program for the production of films with a diameter of approximately 10 cm and a thickness of approximately 0.15 mm is: 0 weight 2 - 3 g polymer;
  • the films are covered with hydrofluoric acid (10% by weight) in open vessels and exposed to RT for one week. Evaporating hydrofluoric acid is replaced by fresh one. After rinsing with water and drying, the etched film pieces show clearly recognizable reflection colors. The examination of ultrathin sections (100 nm) of the films after the etching proves that the SiO 2 cores are detached from the films and that ordered porous films are formed while maintaining the order (FIGS. 1, 2). In the entire cross section of the film, pores are formed by dissolving SiO 2 cores, with almost all SiO 2 cores being removed in a region from the surface of the film to a depth of about 5 ⁇ m.
  • Monomer emulsion I from 9.6 g ALMA, 96 g TBMA, 0.45 g SDS, 0.1 g KOH and 130 g water was metered in continuously over a period of 180 min. The reactor contents are stirred for 30 minutes without further addition. Then 150 mg of sodium peroxodisulfate, dissolved in 5 g of water, are added. After stirring for 15 min, monomer emulsion II from 120 g of styrene, 0.4 g of SDS and 120 g of water is metered in continuously over a period of 200 min. For almost complete reaction of the monomers, the mixture is then stirred for a further 60 min. Dried samples of the latex show a green color.
  • Electron microscopic examination of latex deposits shows that the polymer particles have an irregular shape and an average particle size of approximately 210 nm.
  • the core-shell particles are then precipitated in 1 liter of ethanol, the precipitation is completed by adding 25 g of concentrated aqueous saline, the suspension with 1 liter of distilled water. Water is added, suction filtered and the polymer is dried at 50 ° C. in vacuo.
  • Diameter of about 10 cm and a thickness of about 0.2 mm is:
  • Example 8 Production of molded articles with homogeneous, regularly arranged cavities
  • the films from Example 7 are placed under a UV lamp (high-pressure HG steam lamp, power 300 watts, distance lamp - film: 20 cm) over a period of 24 hours. After UV exposure, the films show brilliant, iridescent color effects.
  • the cavities of the shaped body obtained according to Example 6a, 7 and 8 can be seen in FIG.
  • TEM image Transmission electron microscope image (TEM image) of ultra-thin sections (100 nm) of the cross section of etched films from example 5. A film cross section is shown. In the lower right part of the pictures you can see the epoxy resin used to embed the films. The arrangement of the pores (light) in the polymer matrix (dark) can be seen starting from the film surface.
  • FIG. 2 Scanning electron micrograph (SEM image) of the surface of a film from example 5 etched with HF. Regularly arranged pores can be seen at a damaged area, which have arisen from the loosening of the SiO 2 cores.

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Abstract

L'invention concerne l'utilisation de particules à noyau et enveloppe dont l'enveloppe forme une matrice et le noyau est un élément sensiblement dur, à répartition dimensionnelle monodisperse. L'enveloppe est reliée au noyau par une couche intermédiaire et elle présente des propriétés thermoplastiques. Ces particules sont utilisées pour fabriquer des éléments moulés à cavités homogènes réparties de manière régulière. La présente invention porte également sur un procédé pour fabriquer des éléments moulés à cavités homogènes réparties de manière régulière, ainsi que sur les éléments moulés correspondants.
EP04763795A 2003-09-04 2004-08-04 Utilisation de particules a noyau et enveloppe Withdrawn EP1660415A2 (fr)

Applications Claiming Priority (3)

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DE2003141198 DE10341198A1 (de) 2003-09-04 2003-09-04 Verwendung von Kern-Mantel-Partikeln
DE2003157680 DE10357680A1 (de) 2003-12-10 2003-12-10 Verwendung von Kern-Mantel-Partikeln
PCT/EP2004/008746 WO2005028396A2 (fr) 2003-09-04 2004-08-04 Utilisation de particules a noyau et enveloppe

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DE10245848A1 (de) * 2002-09-30 2004-04-01 Merck Patent Gmbh Verfahren zur Herstellung inverser opalartiger Strukturen
DE102006013055A1 (de) * 2006-03-22 2007-09-27 Merck Patent Gmbh Gasphasen-Infiltrierung von Leuchtstoffen in das Porensystem von inversen Opalen
JP5150898B2 (ja) * 2007-03-22 2013-02-27 国立大学法人神戸大学 複合微細構造体およびその製造方法
KR101573551B1 (ko) * 2007-09-11 2015-12-01 카네카 코포레이션 액상 수지 조성물, 및 그 액상 수지 조성물을 사용한 경화물
GB0720550D0 (en) 2007-10-19 2007-11-28 Rue De Int Ltd Photonic crystal security device multiple optical effects
GB2472987A (en) 2009-08-24 2011-03-02 Cambridge Entpr Ltd Composite optical materials, uses of composite optical materials and methods for the manufacture of composite optical materials
JP5931921B2 (ja) 2011-01-12 2016-06-08 ケンブリッジ エンタープライズ リミテッド 複合光学材料の製造
FR2996418B1 (fr) * 2012-10-09 2015-05-29 Seppic Sa Compositions alimentaires comprenant des capsules obtenues par coacervation ne mettant pas en œuvre de reticulant toxique
JP6490436B2 (ja) 2015-01-30 2019-03-27 サムスン エレクトロニクス カンパニー リミテッド 複合粒子、トナー用外添剤および複合粒子の製造方法
US10007203B2 (en) 2015-01-30 2018-06-26 Samsung Electronics Co., Ltd. Complex particle, external additive for toner and method of preparing complex particle
CN111944191B (zh) * 2020-08-07 2023-04-25 武汉珈源同创科技有限公司 一种量子点荧光微球及其制备方法

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US4683269A (en) * 1985-12-18 1987-07-28 Reichhold Chemicals, Inc. Opaque binder system
JP2790381B2 (ja) * 1990-02-03 1998-08-27 三井化学株式会社 有芯多層構造エマルション粒子
DE19820302A1 (de) * 1998-05-04 2000-02-24 Basf Ag Kern/Schale-Partikel, ihre Herstellung und Verwendung

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WO2005028396A2 (fr) 2005-03-31
WO2005028396A3 (fr) 2005-06-23

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