Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
  • B01F23/41—Emulsifying
  • B01F23/4105—Methods of emulsifying
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
  • B01F23/41—Emulsifying
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/40—Mixing liquids with liquids; Emulsifying
  • B01F23/41—Emulsifying
  • B01F23/413—Homogenising a raw emulsion or making monodisperse or fine emulsions
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/70—Pre-treatment of the materials to be mixed
  • B01F23/702—Cooling materials
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/70—Pre-treatment of the materials to be mixed
  • B01F23/711—Heating materials, e.g. melting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/80—After-treatment of the mixture
  • B01F23/802—Cooling the mixture
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F23/00—Mixing according to the phases to be mixed, e.g. dispersing or emulsifying
  • B01F23/80—After-treatment of the mixture
  • B01F23/811—Heating the mixture
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F25/00—Flow mixers; Mixers for falling materials, e.g. solid particles
  • B01F25/20—Jet mixers, i.e. mixers using high-speed fluid streams
  • B01F25/23—Mixing by intersecting jets
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0418—Geometrical information
  • B01F2215/0427—Numerical distance values, e.g. separation, position
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0418—Geometrical information
  • B01F2215/0431—Numerical size values, e.g. diameter of a hole or conduit, area, volume, length, width, or ratios thereof
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0436—Operational information
  • B01F2215/0468—Numerical pressure values
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
  • B01F—MIXING, e.g. DISSOLVING, EMULSIFYING OR DISPERSING
  • B01F2215/00—Auxiliary or complementary information in relation with mixing
  • B01F2215/04—Technical information in relation with mixing
  • B01F2215/0413—Numerical information
  • B01F2215/0436—Operational information
  • B01F2215/0481—Numerical speed values

Definitions

• the invention relates to a method for producing emulsions.
• emulsions are understood as meaning both colloidal emulsions and technical emulsions, the latter differing from colloidal emulsions in that they have considerably larger particle dimensions in the micrometer range.
• a large number of branches of industry for example the food industry, the pharmaceutical industry and the cosmetics industry, have a high demand for encapsulation, protection or targeted release of hydrophobic substances such as bioactive lipids, odorous substances, antioxidants and pharmaceuticals.
• Emulsions are formed when two or more immiscible liquids are mixed together.
• One of these liquids is usually water soluble and the other is a lipophilic liquid that is immiscible with water.
• either water-in-oil emulsions or oil-in-water emulsions can be produced.
• a disadvantage of emulsions is their instability, which is based on physicochemical mechanisms such as gravity separation, flocculation, coalescence and Ostwald ripening. In oil-in-water emulsions, the most common reason for instability is the gravitational separation in the form of "creaming", which occurs due to the lower density of the oil particles.
• Emulsions with an oil droplet size of more than 10 ⁇ m tend to change into two separate phases within a short time, while for an oil droplet size of less than 1 ⁇ m the stability of the emulsion increases with decreasing oil droplet size.
• an oil droplet size of less than 1 ⁇ m a four times larger energy input is necessary to reduce the oil droplet size by 50%, which limits the minimum oil droplet size that can be achieved.
• due to the energy input there is a risk of the temperature rising to temperatures above 70 ° C, at which the emulsifiers can be destroyed.
• the limiting factors are the pore size of the membranes used and the pressure resulting from the viscosity of the oil phase.
• a microjet reactor according to the EP 1 165 224 B1 is used.
• Such a microjet reactor has at least two opposing nozzles, each with an associated pump and feed line for spraying a liquid medium in each case into a reactor space enclosed by a reactor housing at a common collision point, a first opening being provided in the reactor housing through which a gas, a evaporating liquid, a cooling liquid or a cooling gas can be introduced to maintain the gas atmosphere inside the reactor, in particular at the point of collision of the liquid jets, or to cool the resulting products, and a further opening is provided for removing the resulting products and excess gas from the reactor housing is.
• a gas, an evaporating liquid or a cooling gas is therefore introduced into the reactor space via an opening in order to maintain a gas atmosphere in the interior of the reactor, in particular at the point of collision the liquid jets or to cool the resulting products and the resulting products and excess gas are removed through an opening from the reactor housing by overpressure on the gas inlet side or by negative pressure on the product and gas outlet side.
• a solvent / non-solvent precipitation in such a microjet reactor for example as in the EP 2 550 092 A1 is carried out, a dispersion of the precipitated particles is obtained. With such a reactor it is possible to generate particularly small particles.
• a solvent / non-solvent precipitation is understood to mean that a substance is dissolved in a solvent and collides as a liquid jet with a second liquid jet, the dissolved substance being precipitated again.
• a disadvantage of solvent / non-solvent precipitations is the fact that the dissolved and reprecipitated substance is in particulate form in the solvent-non-solvent mixture after the precipitation.
• the solvent content has the effect that, in many particles, an Ostwald ripening occurs in a time-dependent manner, which causes the particles to grow.
• a device for emulsifying at least two liquids which comprises an emulsion reactor which has an outlet for removing the emulsion resulting from the mixing of the liquids and in which a plurality of nozzles are provided for injection at a substantially common collision point, each Nozzle is assigned a feed line and a pump, each of which pumps a liquid from an assigned tank through the feed line into the emulsion reactor.
• the WO 99/28020 A1 describes a method of making heat sensitive emulsions or dispersions in which the components are pressurized, passed through a first high pressure mixing zone, then cooled in a heat exchanger and then passed through a second high pressure mixing zone.
• the DE 26 04 610 A1 describes a process in which oil and water are sucked in from separate containers in the desired volume ratio and, as a mixture under high pressure in a pipe-nozzle system, is accelerated and decelerated several times at short intervals from a constant low base speed to about ten to twenty times the flow speed and then sprayed directly into the combustion chamber for burning.
• the pressure at the basic flow rate is 130 to 180 bar.
• the GB 331 928 A describes an apparatus for the production of emulsions or dispersions by spraying the components against one another. The pressure of the liquid jets is not specified here.
• the object of the invention is therefore to create a new process for the production of emulsions which also enables the production of asymmetrical emulsions.
• This object is achieved according to the invention in that in a first step at least one pre-emulsion is generated from at least two immiscible liquids and then in a second step at least two liquid streams of the at least one pre-emulsion are pumped through separate nozzles with a defined diameter in a microjet reactor, whereby the pressure of the liquid jets is between 5 and 500 bar in order to achieve the flow velocity of the liquid flows of more than 10 m / s and that the liquid flows meet at a collision point in a room, the room being filled or acted upon with gas and the gas pressure in the space is 0.05 to 30 bar, preferably 0.2 to 10 bar and particularly preferably 0.5 to 5 bar.
• Gas in particular inert gas or inert gas mixtures, but also reactive gas, can be fed into the space through a gas inlet.
• Such a microjet reactor is from EP 1 165 224 B1 famous.
• the droplet size of the emulsion depends on the system and operating parameters, in particular the nozzle size in the microjet reactor and the pump pressure of the conveying pumps for the two liquid flows.
• the collision energy in the microjet reactor does not cause any precipitation reactions, but rather emulsions are formed.
• a homogeneous emulsion with an oil droplet size of less than 1 ⁇ m is achieved due to the kinetic energy, which is also very stable. No additional energy input, such as shear forces, is required for this. It can be carried out in the aqueous phase at temperatures between 0.degree. C. and 100.degree. C., preferably at temperatures between room temperature and 70.degree. C., particularly preferably at temperatures between room temperature and 50.degree.
• the pressure of the liquid jets is between 5 and 5,000 bar, preferably between 10 and 1,000 bar and particularly preferably between 20 and 500 bar.
• the flow rate of the liquid streams and the temperature, the oil droplet size in the emulsion can be influenced.
• the resulting emulsion is discharged from the room through the outlet. There is thus a continuously operating process.
• the diameter of the nozzles is identical or different and is 10 to 5,000 ⁇ m, preferably 50 to 3,000 ⁇ m and particularly preferably 100 to 2,000 ⁇ m. It is possible to work with nozzles of different diameters, for example on one side of a nozzle with a diameter of 100 ⁇ m and on the other side of a nozzle with a diameter of 300 ⁇ m. Of course, the diameters of the nozzles can also be the same on both sides.
• the flow velocities of the liquid streams after the nozzle are identical or different and are more than 20 m / s, preferably more than 50 m / s and particularly preferably more than 100 m / s.
• one of the liquid flows can have a higher flow velocity than the other liquid flow, for example on the one hand 50 m / s and on the other hand 100 m / s.
• the flow speed of the liquid streams after the nozzle can reach 500 m / s or 1,000 m / s.
• the distance between the nozzles is preferably less than 5 cm, preferably less than 3 cm and particularly preferably less than 1 cm.
• the gas pressure in the space is 0.2 to 10 bar and preferably 0.5 to 5 bar.
• the droplet size can also be influenced via the gas pressure.
• a solvent is introduced into the space through a further inlet.
• propylene glycol can be introduced into the room as a further solvent through the further inlet.
• One embodiment of the invention consists in the fact that during the collision there is a pressure of less than 100 bar, preferably less than 50 bar and particularly preferably less than 20 bar in the space.
• the emulsion produced is encapsulated in a further step.
• Examples 1 to 4 show the effects of varying individual parameters, while Examples 5 to 21 contain examples of possible encapsulation processes.
• Oil flow rate (ml / min) Water flow rate (ml / min) Oil droplet size (nm) 10 50 596 20th 100 427 30th 150 348 50 250 294 100 500 257
• the oil droplet size within the emulsion formed thus decreases with increasing flow rates.
• the influence of the diameter of the nozzles was determined by testing various nozzle diameters while using an oil flow rate of 50 ml / min and a water flow rate of 250 ml / min and the gas pressure was 2 bar.
• Nozzle diameter ( ⁇ m) Oil droplet size (nm) 200 294 300 318 400 567 500 785
• Oil and water phases were pre-emulsified and pumped through the two inlets in a closed cycle in order to determine the influence of the number of cycles on the oil droplet size within the emulsion.
• a flow rate of 250 ml / min and a gas pressure of 2 bar prevailed in the room.
• Number of cycles Oil droplet size (nm) 1 650 2 540 3 420 4th 355
• the oil droplet size within the emulsion therefore also decreases with the number of cycles.
• An essential oil to be encapsulated is emulsified at a flow rate of 67 g / min in the microjet reactor with an aqueous sodium caseinate solution (22.4 mg / ml) at a flow rate of 200 g / min in the microjet reactor.
• this emulsion is processed at a flow rate of 200 g / min against an aqueous xanthan solution (0.25%) at 25 g / min.
• the oppositely charged side groups of the protein and the polysaccharide attach to each other. This interaction is strengthened by lowering the pH to pH 4 with 10% citric acid, whereby microcapsules are formed.
• the microcapsules are 50-100 ⁇ m in size.
• An essential oil to be encapsulated is emulsified at a flow rate of 50 g / min in the microjet reactor in an aqueous whey protein isolate solution at a flow rate of 200 g / min. After adding 20% maltodextrin as a carrier material, the emulsion is spray-dried. Drying creates a powder that contains microencapsulated essential oil.
• Example 7 Melt dispersion / matrix encapsulation
• a fragrance to be encapsulated (15-30%) is dissolved in melted Compritol AO 888 at 85 ° C.
• This oil phase is emulsified at 68 ml / min in a 20 ° C. aqueous Tween 20 solution (0.5-1.5%) at 200 ml / min.
• the rapid cooling of the fat results in the formation of particles and thus matrix encapsulation of the fragrance when the emulsion is formed.
• the microcapsules are on average 5 ⁇ m (0.5% Tween 20) or 2 ⁇ m (1.5% Tween 20).
• Example 8 Melt dispersion with modified surface
• a fragrance to be encapsulated (15-30%) is dissolved in melted Compritol AO 888 at 85 ° C.
• This oil phase is emulsified at 68 ml / min in a 20 ° C. cold gum arabic solution (2.5%; 200 ml / min). Due to the rapid cooling of the fat, particles form immediately after the emulsion has formed.
• microcapsules are modified by processing this melt dispersion (200 ml / min) in the microjet reactor against a gelatin solution (2.5%; 150 g / min) at 50 ° C. By lowering the pH to pH 4 with 10% citric acid, the ionic interactions are strengthened and gelled by cooling.
• a hydrophilic polyalcohol to be encapsulated (active ingredient) is added to an aqueous ammonia solution (1%) (water phase) and in the MJR reactor against an emulsifier-containing (polyetheralkyl-polymethylsiloxane) 1% encapsulation solution (TEOS) in Isoparaffin (oil phase) processed.
• a process pressure of 40 bar is set upstream of the nozzles.
• the result is a stable emulsion, at whose phase boundary the encapsulation material is formed by hydrolysis of the precursors.
• the capsules can be separated by simple sedimentation or centrifugation and are between 5 and 10 ⁇ m in size.
• the method indicated in FIG. 1 is applied to the encapsulation substances OTMS, PTMS. With a constant flow rate, the microcapsules obtained have approximately the same properties with a reduced reaction time.
• the method given in FIG. 1 is applied to variable flow rates. By varying the flow rate, ratios of the disperse phase (active substance) to the oil phase of 30:70, 40:60 and 60:40 can be achieved. The size of the microcapsules obtained increases as the proportion of disperse phase (active substance solution) increases.
• the method indicated in FIG. 1 is applied to an encapsulation solution containing TEOS with the modification that the concentration of the emulsifier used was reduced to 50% or 25% of the original concentration.
• the microcapsules obtained are larger than those obtained according to Example 1.
• Example 17 The method given in Example 17 is used with the modification that the capsule hardening by means of trimesoyl chloride solution takes place in situ by continuously introducing the solution into the reactor chamber via the fifth opening of the MJR reactor.
• the capsules obtained have approximately the same properties as those obtained according to Example 9.
• Oil-soluble actives Examples 19-20
• Example 5 The procedure given in Example 5 is applied to oil-soluble encapsulants.
• An oil-soluble active substance to be encapsulated is added to a 20% solution of the encapsulation material (OTMS) in isoparaffin and mixed by stirring at room temperature for 5 min.
• the solution obtained in this way is processed in the MJR reactor at a process pressure of 40 bar against a 2% aqueous emulsifier solution.
• the result is a stable, homogeneous emulsion which, by adding the catalyst dibutyltin laurate (0.5%), hardens the capsules, which can be separated after hardening by means of centrifugation or sedimentation.
• Example 19 The method given in Example 19 is used with the modification that the capsule hardening takes place in situ by means of dibutyltin laurate by continuously introducing the solution into the reactor chamber via the fifth opening of the MJR reactor.
• the capsules obtained have approximately the same properties as those obtained according to Example 19.
• Step 2b (as an alternative to step 2a):
• Step 3b (as an alternative to step 3a):
• pre-emulsion a warm non-solvent
• This pre-emulsion is introduced into the MJR on the right and left with a flow rate ratio of 1: 1.
• the loaded polymer is precipitated on a microscale.
• Step 3c (as an alternative to step 3a or step 3b):
• the modified melt is mixed with part of the heated non-solvent to reduce the melt viscosity.
• the mixture is precipitated with the cold residual non-solvent in the MJR process with precipitation of the polymer beads.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Manufacturing Of Micro-Capsules (AREA)
• Colloid Chemistry (AREA)

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• 2016
  • 2016-01-25 DE DE102016101232.7A patent/DE102016101232A1/de not_active Ceased
• 2017
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  • 2017-01-25 DK DK17706142.1T patent/DK3408015T3/da active
  • 2017-01-25 ES ES17706142T patent/ES2893124T3/es active Active
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  • 2017-01-25 WO PCT/DE2017/100046 patent/WO2017129177A1/de active Application Filing
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