DE102014013354A1 - The invention relates to an apparatus and method for producing microencapsulated paraffin particles by an electrostatic rotary nozzle spray method and the use of this method. The thus encapsulated paraffin particles can be used for - Google Patents

Abstract

The invention relates to an apparatus and method for producing microencapsulated paraffin particles by an electrostatic rotary nozzle spray method. The use of this method, in conjunction with another one of the coagulation method, allows complete coverage of the paraffin particle surface with a polymeric material. The particles according to the invention are characterized in that they contain microencapsulated paraffin particles for phase change materials, PCM, including PCM composites (PCM-V), PCM objects (PCM-O) and PCM systems (PCM-S), classification according to RAL-GZ 896, can be used.

Description

The invention relates to an apparatus and method for producing microencapsulated paraffin particles by an electrostatic rotary nozzle spray method and the use of this method. The thus encapsulated paraffin particles can be used for phase change materials, PCM (phase change material) including PCM composites, PCM objects and PCM systems.

State of the art

Methods such as dropping, stirred tank, multi-fluid nozzle method, double emulsion method, electrostatic microencapsulation, phase separation method (coacervation), interfacial reaction, in situ polymerization for the preparation of microencapsulated particles are known in the art from the prior art.

Furthermore, it is known that spinning polymer blends into nanofibers or spherical particles and subsequently removing a polymer phase results in porous structures on and in nanofiber or globular particles. ( Dissertation M. Rudisile, Marburg, Department of Chemistry Prof. Wendorf, 2006 )

Furthermore, it describes that there is an additional possibility to use the humidity in order to bring about a condensation of water droplets on the "jet". ( Dissertation M. Rudisile, Fiber Matrices of Synthetic and Natural Polymers for Tissue Engineering and Drug Release, p.9, Department of Chemistry Uni-Marburg, Prof. Wendorf and Greiner, 2006 )

A precipitation of polymers in the precipitation bath is called a phase inversion method. The resulting products have a capillary structure. Here again, the coagulation process is the most widely used process for producing materials with an open-pored capillary structure. See article by A. Greiner and JH Wendorff, Electrospinning: A Fascinating Method for the Preparation of Ultra-Thin Fibers, Angew. Chem. 2007, 119, pp. 5787-5789 ,

Due to the variety of precipitation methods, it is possible to produce fine to coarse pores of 100 to 50,000 nm also distributed in layers. Within this polymer layer additional fillers, under the condition, particle size small pore size can be installed and introduced with special Ab- or desorption properties, so that their access is ensured by the capillary structure.

In the coagulation process, the transition from the sol to the gel thread and thus the so-called phase inversion by exchange of the solvent for a precipitant by the polymer immediately immediately immersed in a precipitation bath. In any case, an unlimited solubility of solvent and precipitant into one another is advantageous for the process, as is the case, for example, with DMF, NMP and water. Decisive for the suitability for the coagulation process is the requirement for the coagulation ability of a solution. The decisive criterion for the formation of micro- and nanoporous structures is the precipitant sensitivity, which leads to the formation of associates when purified water is added.

The gel formation in the particle usually leads to the formation of an asymmetric pore structure, since a transport barrier builds up upon contact of the particle with the precipitant, which hinders the diffusing solvent into the precipitant or the precipitant in the particles. For this reason, the precipitation usually takes place by adding 20 to 50% solvent in the precipitation bath.

The principle of phase inversion is used above all in the membrane production of polyarylene sulfones, aromatic polyamide or cellulose acetate and in the production of certain fibers such as polyacrylonitrile and polyurethane.

It is known that the phase inversion of a solution is initiated by changing the thermodynamic state. This can be done by evaporating a part of the solvent or a solvent component, by adding a further component (precipitant) in the solution or by a change in temperature.

For the preparation of nanoparticles and microparticles, the person skilled in a variety of methods are known in which currently the electrospinning process is given much attention.

In the described method of DE 10133393 A1 . WO 2004009887 A1 . DE 19600162 . WO 2004080681 A1 . DE 10355665 A1 . WO 2004048644 A2 . WO 2006089522 A1 . WO 2009010443 and EP 2171136 B1 describe the methods of electrospinning, which typically exposes a polymer solution to a high electric field on an edge serving as an electrode. This can be achieved, for example, by extruding the polymer solution in an electric field under low pressure through a cannula connected to the pole of a voltage source. Due to the resulting electrostatic charge of the polymer solution is formed on the counter electrode directed material flow, which solidifies on the way to the counter electrode. Depending on the electrode geometries, nonwovens are obtained by this method.

The spraying of paint (polymer solution) on a nozzle or edge is described in the article of W. Kleber, Dresden KDT, ELECTRIC Issue 2 (1962) under stadiums for thread and drop formation: formation of small liquid bumps on the nozzle tip, vertical ejection of cylindrical liquid threads, Zerwellen the fluid threads within the upper parts of the spray cone and flight of the atomized droplets under the influence of electric field distribution within relatively sharply defined droplet cone to the counter electrode. ,

The area, which occupies the upper part of the droplet cone in its spatial extent, namely the thread formation in the Zerwellgebiet, was calculated from a lack of knowledge of the processes taking place to the area of the already decaying particles. ( ELECTRIC Issue 2, 1962, p. 48 )

It is taught there that thread length and particle size of the field strength, further from the chemical-physical data of the liquid, electrical conductivity, surface tension, dipole moment and dielectric constant and mechanical data of the atomizer such as overpressure on exit from the nozzle or profile of the atomizer edge, peripheral speed and Wetting degree of the edge is dependent. ( Elektrie Heft 2, 1962, p. 48 )

The rotating bell described by way of example produces an annular spray pattern with a relatively small inner diameter.

The spray pattern is formed by the diameter of the bell, the height of the applied voltage, the distance between the atomizer and the workpiece. Bell diameter is described as 40 to 300 mm. The bell is driven by an electric motor, air turbine or hydraulically. ( ELECTRICAL Issue 2, 1962, p. 49, Figure 4 a )

The mechanism of electrostatic spray painting is used by W. Kleber in plastic and rubber, 10th volume Issue 8, 1963, p 502 , shown in Figure 1 a as an example in Part B and experimental investigation on rotating bells mentioned. The paint (polymer solution) is fed in exactly metered amount via a hollow shaft or the like of the inner surface of the bell. From there it flows as a result of the rotation to the bell edge.

In the edition Plastics and Rubber, Volume 10, Issue 8, 1963, p. 504 W. Kleber performs a fundamental work under Definitions on the basis of the photographic examination with spark chamber illumination, namely spray nebulosity, pointed liquid elevation in more or less dense distances at the periphery of the part of the atomizer disk facing the counterelectrode. Radial to the disc emerging from the spray warts straight liquid thread, Zerwellfaden, single or multiple corrugated, tapered cross-section thread part as a continuation of a stem, droplet cone, flying area of the atomized droplets, spray cone, overall structure of spray wart, stem, Zerwellfaden and droplet cone documented by photographic images and explained.

Further detailed explanations and pictures are described under General observations, influence of the disk speed on the atomization, influence of the height of the tension on the atomization, influence of the degree of wetting of the atomizer edge, influence of the edge profile, influence of the counter electrode and so on W. Kleber in paste and rubber 10th volume Issue 8, 1963, p 504 to 507th ,

Example becomes in Metal surface, 21st year, 1967, No. 6, p. 166, picture 5 , The electrostatic spray painting with the formation of threads on a rapidly rotating bell to stretch the Zerwellfadens and change in shape of the straight thread described. In the supplement to the Hochschulfilm, German Institute for Film, Image and Sound in Teaching and Research, TU Dresden, 1965, Electrostatic atomization of liquids, author W. Kleber, et al. By K.-H. Böttger: The mechanism of the electrostatic paint sprayer on fast rotating bells, plastic and rubber 10, 1965, No. 9, pp. 568-572 Referring to FIG.

In the notes: Zum Mechanism of electrostatic spray painting, I-Lack, Issue 3, 1987, p. 86 , In the photo analysis of the electrostatic atomization process, the most important influencing factors such as liquid parameters, system parameters, air as surrounding medium are described. Table 2, p. 88 describes the basic mechanisms and sub-areas of a paint spray cone of electrostatic atomization. The shredding process is taught on pages 88 and 89.

Connection between conduction, corona and tribocharging with respect to the particle charging on a bell or disc with sharp edge and high rotation at speeds in the range of 20,000 to 60,000 rev / min and the resulting effect of abrasion on air resistance from W. Kleber in Carl Hanser Verlag, Munich, mo Jahrg. 54, 2000, p. 26 disclosed.

In electrostatic spinning, one can distinguish between different mechanisms: the slowly rotating disc or bell. Needles or thin wires and a spray gap between spray and counter electrode ( DE 10 2007 027 014 A1 )

The mechanical high-rotation spiders connected to an electrostatic deposition by means of a bell. ( EP 1999304 B1 ) is also presented in: Nonwoven Days Hof, 09.-10.11.2005, ITV Denkendorf, Advances in Nanofiber Generation, Lecture Martin Dauner and Martin Hoss, Comparison of Spin Solvent Spinning and Electrostatic-Spinning.

task

The object of the present invention is to provide an improved and inexpensive to manufacture device and a method for producing microencapsulated paraffin balls in a high-pressure electrostatic spray-off by means of a bell, in which at least a part of the known disadvantages is excluded. The ejection unit may be mounted on a motion machine and perform movements about the longitudinal, transverse and vertical axis. Resistance to water and media must be fulfilled.

This object is achieved in that a device and a method with the features of the appended claim 1 and a method with the features of claim (1 to 10) takes place. The claims (Aufladungsformen) represent advantageous embodiments of the invention.

A particular advantage of the invention is that in the electrostatic high-rotation Absprühverfahren for the electrostatic charging of the polymer to be spun, this can be done in different ways. During conduction and contact charging, the polymer is electrostatically charged by contact with the metallic rotary bell. In the case of the electrically conductive polymers, contact charging can not readily be used. A high conductivity of the polymer would lead to a short circuit in the power supply. If a small number of different conductive polymers are provided for the change, the polymer supply can be built up in isolation. That is, polymer containers and polymer supply lines are installed in isolation.

In external or corona charging, the rotary bell and the polymer solution supplied to it are at ground potential. The charging of the polymer thread takes place only after leaving the rotary bell by ionization of the polymer particle by an external electrode.

Now, the two forms of charging the external and contact charging combined to form the so-called twin-batch process, both advantages can be interconnected. These are due to the fact that the polymer is also charged in the rotary bell, and an overlay with an additional electric field generated by an external charging electrode leads to a narrow particle guidance of the microencapsulated paraffin spherules located on the way to the counterelectrode.

In addition, it can be isolated from earth by the use of a so-called potential separator, which forms the contact between the bell and the counterelectrode, and the conductive microencapsulated particles formed between them, which are isolated from earth. Thus, the otherwise inevitably resulting short circuit is prevented. This is especially necessary when spraying MWCNT, graphite or graphene of the paraffin-filled polymer due to its extremely good thermal and electrical conductivity.

The high rotation sprayer consists of spray bell ( 1 ), Directing ring ( 2 ), Power turbine ( 3 ), Valve body ( 4 ) and receiving flange ( 5 ).

The polymer to be sprayed is passed through small holes and valves in the rotating bell. The supply of the polymer can be centric or acentric in the bell. The bell drive is performed by a radially driven turbine disk. The dissolved polymer reaches the edge of the rotating bell via the inner surface of the bell and is subject to mechanical, aerodynamic and centrifugal forces. The centrifuged microparticles move radially away from the bell and would not reach the counterelectrode (depositing unit) if not steered axially.

This is achieved by the support of the shaping air. The discharge of the shaping air takes place through a hole circle behind the bell and guides the microencapsulated paraffin balls in the direction of the laying unit.

The shaping air has the undesired effect of the air being moved past in the direction of the extraction unit when it reaches the depositing unit, and the particles located in the deflecting air thus being partially guided past the depositing unit together with the exhaust air.

To reduce this, the bell is set to a high electrostatic potential of 10-100 kV. This ensures that the electrically charged particles are now deposited in their majority on the electrically grounded depositing unit.

This procedure allows very high application efficiencies. The high-rotation spray-on unit can be attached to moving machines, so-called robots, but also to a linear lifting device. Thus, complex surface and curved surface geometries can be coated with particles. Restrictions occur only in depressions on the depositing unit where the formation of a Faraday cage eliminates the electrostatic forces.

The supply of the bell with the polymer can be done by two types, namely the external supply and the internal supply. In the external supply, the bell is mounted on a shaft made of solid material. The polymer in solution and its necessary rinsing agents are passed outside the shaft through the sparger to a unitary polymer manifold which causes the polymer to be centrally introduced into the bell. In this case, simple rolling bearings can be used due to the small shaft diameter. The disadvantage of this arrangement is the higher tendency for soiling of the bell.

The internal supply of the bell by the polymer takes place in that a rotating hollow shaft ensures the media supply to the bell. The polymer can thereby be passed centrally into the rotating bell. A disadvantage of this configuration is a relatively large hollow shaft diameter with the required high speeds. The state of the art is that the bearing principle of these rotating shafts are air bearings. The rotating shaft moves on a compressed air cushion whose thickness is 4 to 5 μm. The bell, when integrated in a moving unit, is subject to radial forces acting on the shaft. Placing the shaft on the bearing shell leads to a higher wear of the bearing. Radial forces occur in the Hochrotationsabsprühen then when the unit on a robot (moving machine) is moved quickly around its longitudinal, transverse and vertical axis.

In this configuration, the moving bell separates the air bearing for the reasons mentioned. Ball bearings with sufficient service life to withstand the high speeds as well as negative and positive accelerations are available on the market today. The built-in weight of this high-rotation sprayer is 3,500 grams, with an outer charging ring, the weight increases to 4,500 grams. The mass is thus below the load limit of standard 5.0 kg robots.

(The rotation frequency is adjustable up to 80,000 rpm, contact charging or external charging and so-called twin-charge charging are possible.) Three integrated valves for polymer, detergent and recirculation of detergent, various bell diameters and media distribution with Lenkluftringen are still features of the high-rotation sprayer.

Surprisingly, the following has been shown, is now through the located directly behind the bell body shaping air ring, instead of the shaping air or a gas, this flows through with water, takes place by the shearing of the water film on the bells surface and edge atomization into fine drops of water. This water mist is charged electrostatically through internal or external charging, or through the Twin-Charge process, and moves to the counter electrode. At the contact points-water mist polymer particles, the exchange with the solvent takes place spontaneously due to phase inversion, leading to pre-coagulation. In this case, a pre-precipitation is carried out by the atmosphere enriched with water vapor. This process is commonly referred to as dry coagulation.

Another process variant is the so-called two-stage coagulation, in which the particles treated by the pre-coagulation (pre-precipitation) are introduced on their way into a further precipitation bath. The temperature of the water in the precipitation bath can be selected at room temperature or elevated temperature. The precipitation bath may be formed as a standing or flowing channel. The particles are conducted through the electrostatically charged water mist and with the electrostatically charged particles to the counter electrode (precipitation bath). The water vapor additionally offered during pre-coagulation (pre-precipitation) ensures the excess of precipitant necessary for the success of phase inversion.

According to the invention, in a further embodiment, the particles with the solvents and paraffin still present in the particle are conducted into the precipitation bath. This is designed as a standing or flowing gully. Here then the complete dissolution of the solvent by phase inversion takes place. The particles are guided on their way to the precipitation bath by electrostatic charging and shaping air. The dissolution of the solvent occurring on the way to the counter electrode (precipitation bath), as known to the person skilled in the art, leads specifically to microscopically fine micropores and macropores of 100 to 50,000 nm.

The precipitation under normal conditions such as 50% rel. Humidity and the corresponding phase transition temperature succeed in principle also. But this leads to a pore depth at the particle surface of 80 nm. The phase inversion becomes time-dependent due to the insufficient supply of precipitant. In practice, this means that the necessarily taking place DMF water exchange without exceeding the phase transition temperature is increased by three to four times in time, thus ultimately leading to a desired, insufficient pore formation.

The coagulation of the droplet is also aided by the high humidity of the surrounding air and exerts a major influence on the kinetics and pore shape of the outer skin of the droplet.

The desired effect is that by this idea, the water vapor molecules already support the coagulation from the outside, and thus expand the precipitant offer. As is known to the person skilled in the art, a partial evaporation of the solvents already takes place on the way of the drops from the bell to the counterelectrode. By a saturated steam atmosphere or targeted adjustment of an NMP or DMF / water mixture in this surrounding atmosphere, complete and premature evaporation of the solvent is prevented.

The porous structure formation of the droplet in the phase inversion is thus dependent on the procedural conditions such as temperature and humidity in the surrounding atmosphere, polymer type and its concentration, viscosity, solvent, temperature, conductivity, dipole formation, dielectricity and the high-rotation spray-on unit such as electric field strength, Geometry of the bell, distance to the counter electrode, charging mode (inside-outer) as well as speed dependent. The surface of the drop can be produced without pores, depending on the setting of the procedural conditions.

The principle of phase inversion is mainly used in membrane production polyarylsulphones (polysulfone, polyethersulfone, polyphenylsulfone), aromatic polyamide, polyethylene, polypropylene, polytetrafluoroethylene, polyvinylidene fluoride and cellulose acetate and for the preparation of certain fibers polyacrylonitrile (PAN), polyurethane (PU), polyarylsulphones (PSU, PESU , PPSU) and polyvinylidene fluoride (PVDF), from.

As known to those skilled in the art, the phase inversion of a solution is initiated by the change in the thermodynamic state. This is done by the evaporation of a portion of the solvent or a solvent component, by the addition of another component (precipitant) in the solution or can be done by means of a temperature change.

The object of the present invention is to produce a microencapsulated paraffin-filled spherical capsule.

Surprisingly, it has been shown that the microencapsulated particle preparation is a combination of state changes. The polymer is not soluble in the precipitant (water). Upon contact with the polymer solution, mass transfer between solvent and precipitant is initiated which causes phase separation and coagulation of the polymer. The change in the geometry of the thread due to Rayleigh instabilities produces spherical droplets called coacervates (droplets of highly concentrated solution) and vacuoles (droplets of dilute solution). From these droplets, the condensation structure is formed. Depending on the given conditions, network or cellular structures are created. When the vacuoles run out of fluid (syneresis), capillary contraction often occurs, which leads to collapse of the structure (collapse). Due to the supporting function of the added non-solvent paraffin, it contributes to the structuring during the precipitation process. This prevents structure collapse.

The process model of structure formation, coagulation with water of a polymer solution described by Gröbe and co-workers in 1966, is still valid today. The sequence model describes the coagulation in the triangular diagram for the ternary mixture polymer / solvent / precipitant. This process variant produces fibers or particles according to the model described by Gröbe, namely formation of a dense outer skin by dripping separation, d. H. By exceeding the stability limit of the polymer / DMF / water ternary system, liquid droplets suddenly form in which the polymer builds up a fine network. The formation of a cavity system in the polymer takes place through the locally different mass transport into the interior of the solution and thus to uneven droplets of growth , The termination of the drop growth is effected by the concentration balance between cavities and polymer substance.

Decisive for the ongoing material equalization processes between the forming and already surrounding phases is not only the kinetics with additives, nucleating agents, pigments (fillers) crucial for the capillary structure, but also those that change the flow and wetting properties of the polymer under the action of an electric field and contribute to its capillary structure.

The skilled person is known that by Wünsch, Kesting and Gröbe, Dissertation Main, 2001, Faserforschung and Textiltechnik 17, 1966, p. 315 In the case of the application for phase inversion of a polymer solution by wet precipitation (coagulation method), the equilibrium states described therein are not achieved in the case of applications for phase mixtures of tenene mixtures. In the case of the high-rotation spray-off method, it is therefore essential to work with a clear excess of precipitant to produce nano- and microencapsulated particles.

According to the method, the necessary precipitant excess is achieved by pre-precipitation by water vapor / air atmosphere or by way of example in a water vapor / air / DMF atmosphere.

After the pre-precipitation and precipitation, the washing and drying takes place. The drying process can be carried out by drying in a high-frequency dryer with heating in an alternating electric field (stray field) in a vacuum or in a standard atmosphere.

embodiments

The processes according to the invention are described with reference to FIGS shown and explained high-spin-spray-injection unit shown. It consists of spray bell, shaping air ring, drive unit, valve body, possibly electrode ring (not shown) and rotating water ring (not shown).

The task is to simplify the methods known from the prior art for producing microencapsulated particles. Here, the core material may be liquid or liquefied.

The object of the invention is therefore to develop a new method by superposition of already known methods from the various known production methods. The invention solves this problem by the fact that a superposition of the process processes such as electrostatic microencapsulation, phase separation method (coacervation) and in-situ polymerization takes place.

Polymers for microencapsulation were prepared in the following composition and steps:

Example I

• a) Stir 25 g RT21 (Rubitherm) in 50 g NMP (BASF) at RT and dissolve.
• b) Stir 25 g of PPSU (Solvay) in 160 g of NMP (BASF) at 80 ° C. and dissolve.

Example I.I.

• a) and b) from Example I then for 30 min. Stir together at 70 ° C in a magnetic stirrer.

Example II

• c) stir in 40 g of RT21 (Rubitherm) in 70 g of NMP (BASF) at RT and dissolve.
• d) Stir 25 g of PPSU (BASF) in 160 g of NMP (BASF) at 80 ° C. and dissolve.

Example I.I.

• a) and b) from Example I for 30 min. Stir together at 70 ° C in a magnetic stirrer.

Example II.I.

• c) and d) from Example II for 30 min. Stir together at 70 ° C in a magnetic stirrer.

Example III

• c) and d) from Example II for 30 min at 70 ° C stir together in a magnetic stirrer.

While retaining the polymers described under Example I to II.I other paraffins on the market of the company. Rubitherm, Berlin, were microencapsulated. These are RT22HC Melting Range (20-23 ° C) Solidification Range (23-20 ° C), RT21HC Melting Range (20-23 ° C) Solidification Range (21-19 ° C) and RT21 Melting Range (18-21 ° C) Solidification Range (22 -19 ° C). In principle, more, but with different melting point and Schmelzenthalpien, can be used.

In order to ensure the electrical conductivity of the polymer for the electrostatic Hochrotationszerstäuber-spraying, 3 ml were removed from a mix batch, which was prepared according to the following recipe: 5 g of TEAB were stirred into 70 g of NMP at RT for 60 min. Of these, 3 ml each were taken and stirred in Example I.I or Example II.I for 30 min at 70 ° C. For Example III.I, no addition of the 3 ml of TEAB Mix batch is made.

The following experimental equipment was provided for the experimental setup:
Ball-bearing, electrostatic high-speed rotary atomizer, manufactured by LacTec-alpha-Bell, including load-dependent speed control, a maximum of 35,000 min ^-1
High voltage supply up to 100 kV, negative DC voltage.

Isolated material supply with tempered polymer storage tank with a gear metering pump, delivery volume max. 60 ml min ^-1
Electric and pneumatic control unit. Ambient conditions 20 ° C at 72% rel. Humidity, bell diameter 70 mm.

The following process parameters were chosen for the experiment:

For experiment A) Example I.I:

High rotation atomizer electrical voltage U = 45 kV, current intensity I = <0.05 mA, speed of the bell n = 10,000 min ^-1 , directing air p = 1 bar, distance bell to substrate surface water channel = 9 cm, polymer flow = 42 ml min ^-1 , electrical conductivity of the polymer batch R _v = 1.6 × 10 ⁵ (ohms) at a measuring voltage of 9 V.

Evaluation: spherical microencapsulated particles, not agglomerated freely floating on the water surface surface, uniform distribution.

For experiment B) Example II.I:

Experiment was then carried out with the following parameters changed: U = -70 kV, guide air p = 1.2 bar, bell distance to the substrate surface water channel = 22 cm, polymer flow = 60 ml min ^-1

Evaluation: spherical microencapsulated particles, not agglomerated, floating freely on the water channel surface, due to increased shaping air excitation and propagation of surface waves in the channel.

For experiment C) Example II.I:

High rotation atomizer electrical voltage U = -70 kV, current intensity I = <0.05 mA, rotational speed of the bell n = 12,000 min ^-1 , directing air p = 1 bar, distance bell to substrate surface water channel = 10 cm, polymer flow = 42 ml min ^-1 , electrical Conductivity of the polymer mixture R _v = 1.6 · 10 ⁵ (ohms) at a measuring voltage of 9 V.

Evaluation: spherical microencapsulated particles, not agglomerated, free floating on the water surface surface, uniform distribution.

For experiment D) Example III.I:

High rotation atomizer without electrical voltage and current, speed of the bell n = 12,000 min ^-1 , guide air p = 0.8 bar, distance of the bell to the substrate surface water channel = 2 cm, polymer delivery = 42 ml min ^-1

Evaluation: also spherical microencapsulated particles, not agglomerated, floating freely on the water channel surface, uniform distribution.

The microencapsulated particles are with their particle diameter in the range of 5.0 to 2000.0 microns.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 10133393 A1 [0012]
• WO 2004009887 A1 [0012]
• DE 19600162 [0012]
• WO 2004080681 A1 [0012]
• DE 10355665 A1 [0012]
• WO 2004048644 A2 [0012]
• WO 2006089522 A1 [0012]
• WO 2009010443 [0012]
• EP 217113681 [0012]
• DE 102007027014 A1 [0024]
• EP 1999304 B1 [0025]

Cited non-patent literature

• Dissertation M. Rudisile, Marburg, Department of Chemistry Prof. Wendorf, 2006 [0003]
• Dissertation M. Rudisile, Fiber Matrices of Synthetic and Natural Polymers for Tissue Engineering and Drug Release, S.9, Department of Chemistry Uni-Marburg, Prof. Wendorf and Greiner, 2006 [0004]
• A. Greiner and JH Wendorff, Electrospinning: A Fascinating Method for the Preparation of Ultra-Thin Fibers, Angew. Chem. 2007, 119, pp. 5787-5789 [0005]
• W. Kleber, KDT Dresden, ELECTRICAL Issue 2 (1962) [0013]
• ELECTRIC Issue 2, 1962, p. 48 [0014]
• Elektrie Heft 2, 1962, p. 48 [0015]
• ELECTRIC Heft 2, 1962, p. 49, picture 4 a [0017]
• W. Kleber in plastic and rubber, Volume 10, Issue 8, 1963, p. 502 [0018]
• Plastics and Rubber, Volume 10, Issue 8, 1963, p. 504 [0019]
• W. Kleber in paste and rubber 10th volume Issue 8, 1963, pp. 504 to 507 [0020]
• Metal surface, 21st year, 1967, No. 6, p. 166, image 5 [0021]
• W. Kleber, et al. By K.-H. Böttger: The mechanism of electrostatic paint sprayers on rapidly rotating bells, plastics and rubber 10, 1965, No. 9, pp. 568 to 572 [0021]
• Mechanism of Electrostatic Paint Sputtering, I-Lack, Issue 3, 1987, p. 86 [0022]
• W. Kleber in Carl Hanser Verlag, Munich, Mo Jahrg. 54, 2000, p. 26 [0023]
• Wünsch, Kesting and Gröbe, Dissertation Main, 2001, Faserforschung und Textiltechnik 17, 1966, p. 315 [0055]

Claims (10)

A process for the preparation of microcapsules, characterized in that the organic PCM, a paraffin having a melting solidification temperature range of 5 ° C to 120 ° C as a core material, a capsule wall made of thermoplastic polymer, which by superimposing the following methods such as: electrostatic microencapsulation, phase inversion method (coacervation) and in-situ polymerization, bundled into one process step, namely the electostatic rotary nozzle spraying process into a precipitation bath, has been simplified. A method according to claim 1, characterized in that the suitable thermoplastics for the electrostatic rotary jet spray-off process are dissolved by a solvent or in a solvent component, and from the appropriate group of polyaryl sulfones (polysulfone, polyethersulfone, polyphenylsulfone), aromatic polyamide, polyethylene, polypropylene, Polytetrafluoroethylene, polyvinylidene fluoride and cellulose acetate was selected. A method according to claim 1 and 2, characterized in that the solvent of the thermoplastic has a solubility to the precipitant water and DMAC, DMF, NMP, THF and particularly preferably NMP or DMF. A method according to claim 1 to 3, characterized in that the electrostatic charge can be carried out on the paint atomizer by external and contact charging with respect to the particle charging. The bell or disc with sharp edge rotating at speeds from 5000 to 60,000 min ^-1 A method according to claim 1 to 4, characterized in that the high voltage supply to the spray-on unit is 10 kV to 100 kV, and the applied current I is between 0.1 and 0.05 mA. A method according to claim 1 to 3, characterized in that the spraying without electrostatic charging, ie only with shaping air occurs. A method according to claim 1 to 5, characterized in that flows through the bell body located at the shaping air ring instead of Lenkluft or a gas of water by shearing on the edge of the bell a water mist, which generates a pre-coagulation on the polymer particles. A method according to claim 1 to 7, characterized in that by a further process variant, a two-stage coagulation, in which by the pre-coagulation (pre-precipitation) of the particle this is then introduced into a further precipitation bath. A method according to claim 1 to 8, characterized in that the sheath (shell) of microencapsulated paraffin particles, pore-free, depending on the setting of the procedural conditions. A method according to claim 1 to 9, characterized in that the prepared microencapsulated paraffin particles for phase change materials (PCM) including PCM composites (PCM-V), PCM objects (PCM-O) and PCM systems (PCM -S), are used.

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