DD202441A5 - PROCESS FOR PREPARING PERLPOLYMERIZATION UNIT PARTICLE PARTICLE SIZE - Google Patents

Abstract

Method of making v. Bead polymers of uniform particle size and uniform quality, according to which from the monomer or polymerization mixture to be polymerized by Einduesen the monomer or polymerization in a substantially immiscible with the monomer or polymerization liquid (continuous phase) monomer or Troepfchen Polymerisationsgemisch produces uniform particle size, these dry droplets uniform size encapsulated according to known methods of microencapsulation with a stable under the applicable polymerization conditions hull, the encapsulated Troepfchen then polymerized, with the stipulation to comply with certain conditions in the process steps of Troepfchen-generation and encapsulation of the Troepfchen ,

Description

3.3

- ~) Berlin, 29.5.1932

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Process for the preparation of bead polymers of uniform particle size

Field of application of the invention

The invention relates to a process for preparing bead polymers of uniform particle size. "The bead polymers prepared according to the invention can be used, for example, as adsorber resins or inert release layer materials for separating layers in mixed-bed filters or as matrices for the production of ion exchangers."

Characteristic of the known , technical solutions

The demands that modern ion exchange technologies have on the properties of the individual types of exchanger are increasingly increasing ». In addition to ever higher demands on capacity, kinetics and resistance to mechanical and osmotic loads increasingly greater uniformity of the grain size is required. Particularly high demands are made on the uniformity of the grain size if hydrodynamics is a decisive parameter of the method used.

For example, high-performance ion exchange filters for high throughputs require a coarse grain of as uniform a size as possible, because the fine grain settles in the intergrain volume of the large pearls and in this way increases the filter resistance. Due to the increased resistance, increased pressure must be applied at the required high flow rates, which in turn can easily break the exchanger beads

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to lead.

Equally important is a largely uniform grain size for exchangers that are used in mixed bed filtration. A very different grain size leads to a strong mixing of the fines of the specifically heavier ion exchanger with the coarser grain of the specifically lighter one. Also in the separation, coating process for mixed-bed filters is for the three components Anionenaustäuscher, separating layer material and cation exchanger. each desired a uniform grain size. For the trouble-free functioning of the countercurrent process described in DE-PS 14 42 689 a resin uniform grain size is also advantageous.

15 There are, therefore, been various attempts to produce ion exchangers or them zugrunde- ^one lying matrices very uniform particle, been made size. ¹ the known processes for the preparation of ion exchangers or their matrices are based either on bead polymers or pearl condensates which are prepared by suspension polymerization.

tion or condensation of Ausgangsverb indungen are obtained, or grinding compound obtained in crosslinked polymers or polycondensates. In both techniques, the particles fall into a particle size distribution, which is often due to a. Gauss-Kur ve _; In order to approach the desired uniformity of grain size, physical separation techniques such as screening or fractionated floating are required. Such separation methods are firstly

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consuming and 'secondly have the serious drawback that the necessarily inevitably incurred over- and undersized grain is often no longer, but at least only difficult to exploit. The amount of unwanted undersize or oversize increases in these processes with increasing demands on the uniformity of the grain size.

In the case of perfluoropolymers, the average particle size can be influenced to a limited extent by the polymerization conditions, but the width of the particle size spectrum can only be influenced to a very limited extent. For example, U.S. Patent No. 4,129,770 discloses suspension polymerizations which help to achieve some narrowing of the particle size distribution. However, only the amounts of undersize and oversize are reduced, particles of uniform particle sizes are not available with them.

Also, the process described in U.S. Patent No. 3,784,491 for the preparation of polymer particles of uniform size provides no bead polymers more uniform

Grain size According to this method, the liquid droplets generated from the mixture to be polymerized are protected from agglomeration by coating with soluble gelatin-containing complex coacervates. However, since the liquid droplets are already subjected to shearing forces before they are sheathed, which causes the droplets to collapse and break up, particles are mixed according to the method.

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enveloped the most diverse particle size. The wrapping therefore does not result in the desired polymer particles of uniform grain size. In addition, the soluble gelatina-containing complex coacervates proposed for coating the liquid droplets are liquid and therefore do not protect the droplets from being broken even after being enveloped by the action of shearing forces. In addition, the liquid shells dissolve under the preferred alkaline polymerization conditions.

A more favorable process for the preparation of bead polymers of uniform particle size is described in US-PS 39 22 255. According to this method, the monomer droplets produced by a nozzle bottom are transferred into a reaction column in which they remain until the polymerization has progressed so far that they can be removed from the column without being damaged. The residence time is set by a buoyancy der.Tropfchen opposite current of a continuous phase. Apart from the high technical. Effort is. the great disadvantage of this method is that the residence time controlling liquid flow must have such a high linear velocity, so that a velocity profile is formed over the column cross-section, which leads to a non-uniform residence time for the individual monomer droplets in the polymerization. The different residence times of the monomer droplets - leads to quality differences

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the Ausauscherperien obtained from the polymers. The quality difference between the polymer beads caused by the extreme hydrodynamic conditions of the polymerization column severely restricts the usefulness of the process.

Also, the process for the encapsulation of liquids, z.3. In the processes described in US Pat. Nos. 3,429,327 and 3,577,515, no suggestion was made to solve the technical problem of preparing bead polymers of uniform particle size and quality, since neither capsules of uniform particle size nor uniform physical properties were obtained by these processes to be obtained.

Thus, the method for encapsulating liquids described in US Pat. No. 3 4,229,827 does not yield capsules of the same size, because, as a result of the encapsulation conditions used, the formation of uniformly round droplets due to an early onset of the capsule wall, if not prevented, then at least strong 3,757,515, column 2, line 65, column 3, line 5). The in the. However, US Pat. No. 3,577,515 to avoid the disadvantages inherent in the method proposed in US Pat. No. 3,429,827 does not lead to capsules. -. , uniform size, because the droplets before forming a stable capsule wall, due to the shear forces acting on them by merging and dividing different sizes

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and consequently change into capsules of different sizes.

iel the invention

The aim of the invention is to provide an improved process with which bead polymers of uniform particle size can be prepared in a simple manner.

Explanation of the essence of the invention

It is an object of the present invention to prepare bead polymers of uniform particle size and uniform quality by adding ¹ from the monomer or polymerization mixture to be polymerized by canning the monomer or polymerization mixture into a liquid which is substantially immiscible with the monomer or polymerization mixture (continuous phase). Monomer droplets or polymerization mixture droplets of uniform particle size produced, these droplets of uniform size encapsulated according to known methods of microencapsulation with a stable under the applicable polymerization conditions envelope, the encapsulated droplets then polymerized and in the process steps of droplet production and Verkapseins the Droplet meets certain conditions.

The invention therefore relates to a process for the preparation of bead polymers of uniform particle size and uniform quality, which is characterized in that

a) produces droplets of uniform size from the monomer or polymerization mixture to be polymerized by injection into a liquid which is substantially immiscible with the monomer or polymerization mixture and is continuously supplied;

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b) these droplets of uniform size in said

Liquid continuously according to known methods of microencapsulation either directly with. a shell which is stable under the polymerization conditions to be used or which is initially encapsulated with a shell which is stable against shearing forces and hardens this sheathing-stable shell continuously or discontinuously in a second substep of a shell which is stable under the polymerization conditions to be used;

c) the mi '; one under the applicable polymerization conditions stable shell, Verkaoselten monomer or, polymerization mixture droplets then polymerized ', with the proviso,

et) that the monomer or the polymerization mixture in the DC to the continuous supply. introduced continuous phase in this;

that the production of the droplets and their encapsulation in different regions of the reaction vessel. undertakes;

) /) that the process is performed a) and b) in such a way that the droplets do not affect the integrity of the droplets from their generation until their encapsulation.

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The encapsulation with a shell stable under the polymerization conditions to be used is then carried out in two substeps if the envelopes produced around the droplets by the methods of microencapsulation are stable against shear forces but not under the polymerization conditions to be used.

In this case, the casings must be in a second process step, which is continuous or discontinuous.

It can be carried out loosely, under the poly-

be hardened stable conditions stable conditions. The curing step may be carried out in a separate operation in a separate reaction vessel; but preferably it will be in the same reaction vessel

'5 ν org, ο mm s.

On the other hand, if the envelopes around the droplets produced by the method of microencapsulation are already stable under the polymerization conditions to be used, the curing step and the encapsulation with the polymerization conditions which are to be used are eliminated. Cases is executed in one step.

In the context of the process according to the invention, sheathings are referred to as sheathings when, without being damaged, they withstand stirring motions of an intensity which are used under the conditions of customary suspension polymerizations in order to produce droplets of the same size. '

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The erfindungsgeinäße combination of generating monomer or. Polymerization mixture droplets of uniform size, stabilization of these droplets by encapsulation and polymerization of the encapsulated with a stable under the polymerization conditions.Sülls droplets and 'this under certain conditions, bead polymers are obtained, the beads themselves by approximately the same particle size and by. Uniformity in their physical properties such as grain stability, breaking strength etc. 'Λ.

The process according to the invention is suitable for the preparation of bead polymers of uniform particle size from a wide variety of monomers. The only prerequisite for the applicability of the process is that the polymerization mixture is liquid under the Verdusungsbedingungen. In the context of the present invention, the term polymerization mixture is to be understood as meaning monomers or monomer mixtures which are to be polymerized and are admixed with customary polymerization additives.

As usual polymerization additives are, in particular, polymerization initiators (radical formers such as azoisobutyronitrile and dibenzoyl peroxide) and polymerization inhibitors, furthermore inert liquids and polymers which upon polymerization undergo a structural change, e.g. Macroporosity, cause the polymer called.

The Polymerisatiojisgemische can also dyes

and, if the bead polymers · ^l

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- ίο -

Extracting agents for the liquid-liquid extraction should be included in copolymerized form, also containing extractants for liquid-liquid extraction.

The polymerization mixtures may also contain compounds which react with other compounds to form the capsule wall.

The process according to the invention is suitable for the preparation of both gelatinous and macroporous bead polymers.

Examples of monomers which can be used in the process according to the invention are: monounsaturated compounds such as mono vinyl compounds, e.g. Styrene. Vinyltoluene, ethylstyrene, ^ -methylstyrene and their halogenated derivatives such as chlorostyrene; also vinylbenzene chloride, acrylic acid, its salts and its esters, especially the methyl and. Ethyl esters, methacrylic acid, their salts and their esters, especially the methyl ester, and also the nitriles and amides of acrylic and methacrylic acid.

In particular, polyunsaturated compounds such as divinylbenzene, divinyltoluene, trivinylbenzene, divinylnaphthalene, trivinylnaphthalene, diethyleneglycol divinyl ether, trivinylcyclohexane, octadiene-1,7, heptadiene-, 1,6-hexadiene-1 are mentioned as polyunsaturated compounds , 5, methacrylic esters of polyhydric alcohols, such as ethylene glycol, and methylene Ν, Ν'bisacrylamide. · -Τ

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In the process according to the invention, the following monomers have proven to be particularly useful: Monomers: Styrene, methyl- styrene, ethylstyrene, chlorostyrene, esters and / or amides of (meth) acrylic acid, acrylonitrile, divinylbenzene compounds, divinylbenzene, Divinyltoluene, trivinylbenzene ', diethylene glycol divinyl ether, trivinylcyclohexane, octadiene-1,7, heptadiene-1, β, hexadiene-1,5 and / or methacrylic acid esters of polyhydric alcohols,

The production of droplets of equal size by atomization is known (see, for example, Naefe et al., Chem. Ing. Techn. 50 , 4 (1978) p. 321, and also US Pat. No. 3,922,255). The outflow rates required for disintegration into droplets of equal size can be determined by the Naefe et al., Loc. cit. calculated formula

Injection of the monomer or polymerization mixture in the mit¬dem monomer or polymerization mixture substantially immiscible, continuously supplied liquid (continuous phase) to produce the monomer droplets uniform particle size is carried out in the simplest case by means of a capillary, through which the liquid monomer or polymerization flows into the continuous phase. When the monomer stream exits into the continuous phase, decomposition of the monomer jet into droplets of the same size occurs. In technical systems, perforated discs with capillary holes or similar devices may be substituted for a single capillary. The particle size is determined by the inner diameter of the capillary or Kapillarbohrungen.

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In the method according to the invention, the range of the reaction vessel in which the monomer jet enters the continuous phase and the monomer droplets formed in the continuous phase during jet decay assume their final spherical shape is called the atomization region.

This area is followed by the encapsulation coverage, i. the region of the reaction vessel in which the ready-formed monomer droplets are provided with a polymerization condition which is to be used under the conditions or a sheath that is stable against shear forces.

It is essential to the invention that the atomization region and the encapsulation region are two different regions, ie regions which are passed through in succession by the monomer droplets. and that not, as in the known methods, such as the method described in US-PS 34 29 8 27, atomized and encapsulated in the same region of the reaction vessel. The inventive separation of atomization and Verkapselungsb.ereich prevents parts of the monomer jet already encapsulated in their droplets before their complete disintegration and. on . Thus coated particles of different size and shape and subsequently polymerized werden..Verdüsungsbereich and encapsulant may be prepared by the ^"v <free movement of the monomer droplets in the flowing continuous phase does not impede

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mechanical devices, such as tapers, the reaction tube , funnel-shaped internals in the Reäktionsgefäß , be delimited from each other. But you can also go directly into each other.

It is also essential to the invention that from the generation to the finished. Encapsulation of the monomer droplets does not affect forces on the droplets that cause a change in the integrity of the individual droplets. As such, according to the invention, shear forces, as they attack monomer droplets, are most commonly called shear systems when systems are agitated from monomer droplets dispersed in a continuous phase.

The attack of shear forces on the case of the jet-T5 case generated equal sized monomer droplets is inventively avoided by these droplets are hydrodynamically transported from the atomization region and then through the encapsulation region.

In accordance with the present invention, the movement caused by the density difference between monomer droplets and continuous phase, ie, the drift of the droplets in the continuous phase and the flow of the continuous phase, are used to hydrodynamically transport the droplets through the reaction vessel , ie from the atomization area and exploited by the encapsulation area ^% . From-

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Use of these effects is made possible by the fact that droplets and continuous phase are passed through the reaction vessel in cocurrent.

As a continuous ,. For the lipophilic monomers such as styrenes, (meth) acrylic acid esters, (meth) acrylonitrile, divinylbenzene or lipophilic polymerization mixtures, water or dilute aqueous solutions of the substances which are essentially immiscible with the monomer or polymerization mixture have to be used the encapsulation are conducive, eg dilute solutions of bases, such as soda and / or of suitable suspension stabilizers, such as preferably gelatin, for polar water-soluble monomers, such as (meth) acrylic acid or polymerization mixtures are hydrophobic media, ζ.B. aliphatic and aromatic (halogen) hydrocarbons or silicone oils.

_The. -Ratio of the volumes ^^: V _mQno ( _vcont = volume of the continuous phase; V '= volume of the

mono

Monomer or, polymerization mixture) should not fall below the value 0.1. Depending on the encapsulation method used, the volume ratio is 0.1 to 0. In the encapsulation according to the coacervation method, it is preferably about 3 to 60 and in the encapsulation according to the complex coacervation and the phase boundary reaction method about 1 to 20%.

The upper limit of the volume ratios is determined by the cost-effectiveness of the method, because the

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1S-

Space-time yield of encapsulated monomer droplets decreases with increasing ratio. As the encapsulation of monomer droplets of the same size as such does not differ from the known continuous and discontinuous encapsulation, in principle the volume ratios and also the concentrations of the various components as used in the known encapsulation processes e.g. In'the survey work by Kondo Surf, Colloid Be ,. 10, 19 78, pp. 1-43 and Kirk-Othmer, Encyclopedia of Chemical Technology, Sec. Ed. Vol.13, S-436-456 are described or cited. '

That ^; Injection of the monomer or polymerization mixture is usually carried out at temperatures of 0 to 9 5 ⁰ C, preferably at 5 to 70 ⁰ C.

When the monomer or polymerization mixture is injected into the continuous phase, the continuous phase flows in a direct current to the polymerization mixture jet. Has proven particularly useful for injecting the. Use of concentric two-fluid nozzles. In these, the polymerization mixture flows through the inner, the "continuous phase through the outer of the two concentrically arranged nozzles.

In order to exclude interferences during jet decay, which "affect the uniformity of the droplet size, it may be advantageous to add the polymerization mixture beam in longitudinal oscillations of suitable frequency

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offset. This can be, for example, ' by the action of periodic pressure fluctuations, such as sound waves or periodic movement of the nozzle.

Advantageously, the continuous phase contains dissolved substances (droplet stabilizers) which prevent the polymerization mixture droplets from flowing into one another before the encapsulation step The droplet stabilizers which are suitable are, for example, the suspending aids known from the polymerization technology, eg. 3. Polyvinyl alcohol or carboxymethyl cellulose The use of such droplet stabilizers has proved to be particularly advantageous, which can simultaneously serve to build up the capsule wall, such stabilizers being, for example, gelatin and agar agar.

The concentration of the stabilizers in the continuous phase is usually 0.01 to 10% by weight based on the weight of the continuous phase.

On. the generation of the polymerization mixture droplets of uniform size is followed by the encapsulation.

For encapsulation, the droplets are moved from the region in which they were generated (atomization region) into the adjacent encapsulation region. The temperature of the encapsulation region can be set independently of the temperature of the atomization region. Except "- · _f where the encapsulant is equipped with devices which permit the supply of other liquid components ·.

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The encapsulation of the uniformized particle size stabilized polymerization mixture droplets is carried out continuously according to per se known methods of microencapsulation. Such known methods are, for example:

a) coacervation

In coacervation, a colloid-rich phase forms, which settles around the polymerization mixture droplet. For encapsulation by coacervation, hydrophilic colloids such as gelatin or agar-agar are suitable. In order to trigger the coacervation, for example, an aqueous salt solution is supplied to the encapsulation area. As salts, alkali sulfates, especially sodium sulfate, have proven useful when using gelatin as the hydrophilic colloid. The encapsulation by means of coacervation can be carried out in a particularly simple manner by selecting the aqueous solution of a hydrophilic colloid, such as gelatin or agar-agar, as the continuous phase in which the polymerization mixture jet is decayed. The jet disintegration is carried out at temperatures above the gelation temperature of the colloid.

The formation of the coacervate shell is followed by its solidification by cooling below the gelation temperature. The coacervate produced in this way. Sheath is against shear forces, but often

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not: stable under the applicable polymerization conditions. In order to obtain stable envelopes under the polymerization conditions to be used, the encapsulated particles are subjected to chemical hardening. Method of chemical curing, e.g. Curing of gelatin with aldehydes, such as formaldehyde, are known (see, for example, U.S. Patents 2,800,458). The chemical hardening of the particles can be carried out continuously or discontinuously in the same or another reaction vessel.

b) complex coacervation

In addition to the complex coacervation, a colloid-rich phase is formed from two differently charged colloids (polyelectrolytes) that surround the monomer droplet. For the encapsulation by complex

.. ·

coacervation are suitable ζ.B. Systems of gelatin and gum arabic or of gelatin and special copolymerizate mixtures of a copolymer with randomly distributed residues of acrylamide and maleic acid or maleic anhydride and a copolymer with randomly distributed residues of acrylamide, acrylic acid and maleic acid. Such copolymer mixtures are e.g. in the.

U.S. Patent 4,18V, 639 'as complex coacervation components. For example, to induce complex coacervation, the pH of the encapsulation region is increased by the addition of acids, e.g.

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in the system gelatin / gum arabic, adjusted so that only one of the originally in the same direction charged polyelectrolytes changes its charge sign. Subsequent to the formation of the complex coacervate shell around the polymerization mixture droplet, the droplet moves into a portion of the encapsulation region that is set at a temperature below the gelation temperature.

Although the complex coacervate shell thus produced is stable to shear forces, it is often not stable under the polymerization conditions to be used. In order to obtain stable envelopes under the polymerization conditions to be used, the encapsulated particles are usually subjected to chemical curing. Such chemical curing processes, eg. for the hardening of gelatin-containing capsule walls with aldehydes such as formaldehyde are known (see US Patent 2,800,457).

c) The interfacial reaction

In the encapsulation by interfacial reaction, the polymerization mixture droplets enveloping capsule wall is formed by a component contained in the polymerization mixture 1 "> * a of the continuous phase added in encapsulant component 2 at the phase ¹ cross-flat droplet / continuous phase under

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Film formation reacts. In practice, this encapsulation is carried out by interfacial reaction in such a way that one adds to the polymerization mixture, a component 1 which is miscible with this, but substantially immiscible with the continuous phase. After dividing the polymerization mixture into droplets of equal size, the droplets being stabilized by any suspension aid, the droplet swarm moves into the encapsulation part. Here is a component 2 is fed. This component 2 is soluble in the continuous phase. Component pairs K./K-, which react at the phase interface with film formation, are known in large numbers.

Examples which may be mentioned are the halides of polybasic acids such as sebacyl chloride, terephthaloyl chloride, phosgene, polyfunctional isocyanates such as toluene-2,4-diisocyanate, hexamethylene diisocyanate, chlorides of polybasic sulfonic acids such as 1,3-benzenedisulfonyl chloride, on the one hand and polyfunctional amines, such as hexamethylenediamine, and polyhydric hydroxy compounds such as pyrogallol, bisphenol A, on the other hand, which react to form polymeric carboxylic acid amides and esters, to polyureas and polyurethanes, to polymeric sulfonamides and sulfonic acid esters (see, for example, PG Morgan, "Interfacial Polycondensation, A. Versatile Method of Polymer Preparation", Soc . *, Plastics Engineers Journal "_1_5_, 485-495)). the different reactivity of the various components · pairs K ₁ / K is taken into account by adjusting the residence time in the encapsulant and <adjust certain temperatures.

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In some cases, it has been found to be advantageous to use phosgene surface reaction promoting substances, e.g. Base in Polykondensationsraktionen, where acids arise to use. These adjuvants are preferably added to the continuous phase of the encapsulation region.

Preferably, the complex coacervation is used.

The process steps essential to the invention-generation of uniformly sized polymerization mixture droplets by injecting the polymerization mixture cocurrently into the continuously fed continuous phase and encapsulating the droplets of the same size-can be carried out in a particularly simple manner in a reaction column as described in FIG. The arrangement described in Fig. T is preferably used when the polymerization mixture to be encapsulated has a lower or the same density as the continuous phase. In Fig. 1, section β denotes the atomization region of the reaction column 1, i.e., the reaction zone. the area in which the jet disintegration of the injected by nozzle 2 polymerization mixture and the droplets formed during the jet disintegration take on their final spherical shape .. From feed 3. the solution flows (continuous phase), which stabilizes the same size droplets .. In the lower part of the section. 7 is continuously metered through the feed line 4, the component which triggers the encapsulation. The supply line 5 can be used to strengthen solidifying components.

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In section 8, hardening may take place. The individual sections 5; 7; S of the reaction column 1 can be tempered independently of each other and provided with control instrunents, such as thermometers and pH meters. From Fig. 1 it can be seen that the encapsulated polymerization mixture droplets can form undisturbed by shear forces. Encapsulated polymerization mixture droplets are present on the outlet 9 of the reaction column 1 which is designed as an overflow, the integrity of which is no longer violated even during the subsequent action of mechanical forces, for example when stirring in the agitator vessel 10.

For the encapsulation of polymerization mixtures which have a higher density than the continuous phase, a reaction column 1 of the same type as described in FIG. 1 is suitable, except that in this case in section 6 of column 1 the inlet nozzle for the polymerization mixture 'and the supply line 3 for the continuous phase at the upper end of the reaction column and section 8 and outlet 9 at the lower end of the reaction column 1 are »

The »polymerization of the encapsulated polymerization mixture

The polymerization mixture droplets are found after encapsulation in a state of stirring with heating permits handling, z, B., ohne.daß the integrity of the encapsulated droplet is injured.

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This is a significant difference to conventional suspension polymerizations in which the droplets are not stable as discrete individuals until a certain degree of polymerization is achieved due to dicing and confluence. By contrast, the encapsulated monomer droplets preserve their integrity and thus their uniform size.

The polymerization of the polymerization mixture present in the encapsulated droplets by multi - effect hour heating the hardened capsules optionally in aqueous suspension at temperatures of 40 to 95 ⁰ C. The polymerization of the encapsulated polymerization mixture droplets can be carried out in the same containers as used in conventional suspension polymerization.

Removing the capsule wall

After the polymerization process is a solid, dimensionally stable bead polymer. From this, the capsule wall can be removed in a separate process step. But the capsule wall can also - if the bead polymer is to be further processed on ion exchangers - be removed when introducing the functional groups.

a) The removal of the capsule wall in separate Ver. method step

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To remove the capsule wall, the encapsulated bead polymer is subjected to a chemical treatment which destroys the capsule wall. The type of chemical treatment depends on the chemical structure of the capsule wall. For example, capsule walls of gelatin or hardened gelatin are prepared by heating the encapsulated per-polymers with dilute aqueous acids such as dilute sulfuric acid or aqueous bases for several hours, 2.B. dilute sodium hydroxide solution, removed. Similar or similar hydrolytic degradation also occurs in the destruction of polyamide capsule walls such as hexamethylenediamine and adipic acid, polyesters such as terephthalic chloride and bisphenol A, and polyureas such as toluene-2,4-diisocyanate and hexamethylenediamine applied.

b) Removing the capsule wall when introducing functional groups

The introduction of functional groups into polymers occurs in most cases under drastic conditions. Thus, to introduce sulfonic acid groups into crosslinked polystyrene, the bead polymer is treated with hot concentrated sulfuric acid. In alkaline saponification of crosslinked polyacrylic acid esters, the bead polymers are heated for several hours with 40% sodium hydroxide solution. Under these conditions, the capsule wall is destroyed at the same time, and the removal of the capsule wall can be carried out in one step with the inlet.

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management dsr functional groups. The introduction of the functional groups is not impaired by the capsule wall in any way.

Introduce functional groups

The introduction of functional groups in the inventively prepared polymer beads of uniform particle size by known methods, A top view of this method is found, for _#. B »in Ulimann's Encyclopedia of Technical Chemistry ,. 4th edition, volume 13, pages 300 to 303,

The bead polymers of uniform particle size produced by the process according to the invention can be used as such, z, B "as adsorber resins or inert separating materials for separating layers in mixed-bed filters or, as already indicated above, they serve as Hatrises for the preparation of ion exchangers,

Working Example

The invention is explained in more detail below with reference to some examples.

The parts used in the following examples are by weight unless otherwise stated.

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example 1

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In the apparatus described in Fig. 1 is through the capillary 2 (inner diameter: 0.35 mm, Kapillarenmäterial: stainless steel) with a 45 ⁰ C heat solution of 86 parts of styrene, 8 parts divinyl benzene, 5 parts of ethyl styrene and 1 part dibenzoyl peroxide with injected at a rate of 2.7 ml / min. As the continuous phase, is a heated to 55 ⁰ C aqueous' 10% gelatine solution (pigskin gelatin). This continuous phase has a pH of 7.8 and is fed through 3 at a rate of 12 ml / min. The atomizing area 6 is maintained at a temperature of SO ⁰ C. Through the feed line 4, an aqueous 20% sodium sulfate solution is added at a rate of 4.7 ml / min.

In the encapsulation region 7, the temperature of the continuous phase is controlled so that it drops from 5O ⁰ C (at the lower end) to 15 ⁰ C ... (at the upper end). 5, an aqueous 5% sodium sulfate solution at a temperature of 15 ⁰ C at a rate of 100 ml / min. zugeführt.-

The capsule suspension ion flowing out at 9, is ¹ in one

  : Stirred tank 10 transferred and stirred there for 2 hours

''. '' , , · .- · -. ... , ~ ~, and then washed with water at a temperature of 15 ⁰ C. Then the suspension is mixed with 10 ml of formalin (36%) and 10 -10 g of disodium hydrogen phosphate dodecahydrate per liter of aqueous phase with stirring. In the course

- From 2 hours, the suspension is heated to 25 ° C. -t

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The capsules are then befreit- by water washing of excess formalin Then, the polymerization mixture suspended in the capsules by 10-hour heating the 'water-hardened capsules is polymer-ized at 70 ⁰ C with stirring. That up

* this way obtained encapsulated Perlpolymerlsat from gel, with Divihy! benzol crosslinked! Polystyrene, after separation, washing and drying, without prior removal of the capsule wall, by Sulfqnieren

in a known manner (see ullmann loc cit pp 3-0 3) in a strongly acidic cation exchanger ..

The grain size of the strongly acidic cation exchanger (Na form) thus obtained is in the range 0.8-1.2 mm; 80% of the beads have a particle size in the range 0.9-1.1 mm.

The usual polymerization of the same polymerization mixture in. a 0 ', 2% aqueous Natriumcarboxymethy cellulose with subsequent sulfonation supplies, however, a cation exchanger, in which only 53% of the beads have a particle size of 0.8-1.2 mm and only 29% of the beads have a particle size of 0 "> .9 - 1.1 mnf.

example 2 . ^: - ''"'

In the apparatus described in Fig. 1 is through the capillary 2 (inner diameter: 0.4 mm, capillary material: stainless steel) a 4O ⁰ C warm solution of 91 parts of styrene, 5 parts -Di ν in γ! Benzene, 3 parts of ethyl styrene, a Part Azoisobutyronitrile and 60 parts of isododecane -t at a rate of 4.8.ml / min injected.

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The continuous phase used is a heated to 45 ⁰ C aqueous solution containing 1 wt .-% gelatin (pig skin gelatin) and 1 wt .-% gum arabic. The continuous phase has a pH of 5.7 and is fed through 3 at a rate of 15.3 ml / min. The atomizing area 6 is maintained at a temperature of 45 ^° C. Through the feed line 4 0.1 normal hydrochloric acid is supplied to the extent as is required to adjust the pH-value of the continuous 1O _- phase to 4.0 (+/- 0; 1) to decrease.

In the encapsulation region 7, the temperature of the continuous phase is controlled so that it drops from 45 ⁰ C (at the lower end) to 15 ⁰ C (at the upper end). 5, an ice-water stream is fed at a rate of 20 ml / min.

The exiting at 9 capsule suspension is transferred .in a stirring vessel 10 where it is stirred for 3 hours at ⁰ C Q. Then the suspension is mixed with 30 ml of formalin solution (36% strength) per 1 aqueous phase, 5% sodium hydroxide solution until the alkaline reaction and 20 g of disodium hydrogen phosphate dodecahydrate per 1 aqueous phase. Subsequently, the capsule suspension is stirred for 4 hours at 25 ⁰ C.

Then the cured capsules are washed with water and stirred for 10 hours at 70 ⁰ C in aqueous suspension. After separation from the aqueous phase, the encapsulated bead polymer is washed and dried.

Le A 20 486

The resulting encapsulated polymer of macroporous polystyrene cross-linked with divinylbenzene is subsequently subjected to the process described in US Pat converted with chloromethane into a strongly basic anion exchanger.

The grain size of the thus obtained strong base anion exchanger (Cl-form) is in the range 0.8-1.3 mm; 91% of the beads have a grain size in the range 0.9-1.2 mm.

The usual polymerization of the same polymerization mixture, in a 0.2% aqueous sodium carüoxymethylcellulose fleet followed by amidomethylation and quaternization, however, provides an anionic ion exchanger, in which only 54% of the beads have a particle size of 0.8-1.3 mm and only 31% of the beads have a grain size of 0.9-1.2, / mm.

Example 3

In the apparatus described in Fig. 1 is through the capillary 2 (inner diameter: o, 35 mm, capillary material: stainless steel) cooled to 5 ⁰ C solution consisting of a part of azoisobutyronitrile, 1.5 parts of sebacoyl chloride and a dehydrated with calcium chloride mixture of 86 parts of styrene, 8 parts of divinylbenzene and 5 parts of ethyl styrene was freshly prepared, injected at a rate of 2.4 ml / min. As kon- "*

Le A 20 4 86

2373

Continuous phase is used: a cooled to 5 ⁰ C, 0.5% aqueous polyvinyl alcohol solution. This continuous phase is fed through a 3 at a rate of 7.4 ml / min. The atomizing area β becomes open. maintained at a temperature of 5 ⁰ C. Through the feed line 4, an aqueous solution containing 12 wt .-% of sodium carbonate and 8 wt .-% of hexamethylenediamine, at a rate of 2.2 ml / min in the column eindosiert- The encapsulant 7 is given to a temperature of 25 ⁰ C held.

The capsule suspension effluent at 9 is transferred to an agitator vessel where it is washed with water at room temperature.

Subsequently, the PoIymerisationsgemisch contained in the capsules is polymerized by 10 hours of stirring the aqueous capsule suspension at 7O ⁰ C. ,

The thus obtained encapsulated bead polymer of polystyrene crosslinked with divinylbenzene polystyrene is then treated with 50% sulfuric acid at 12O ⁰ C to remove the capsule wall. After separation from the aqueous phase, the bead polymer is washed and dried.

The particle size of the polystyrene bead polymer thus obtained is in the range of 0 _Λ 5-0.9 mm; 82% of the beads have a particle size of 0.63-0.8 mm ^. '

Le A 20 486

4 29.6.1932

7 QQ Π Q ^{ΑΡ C} ° ^{8 F / 237 380/8}

/ j QU Q -31-. 50 435/11

By contrast, the usual bead polymerization of the same polymerization mixture in a 0.2% aqueous mixture of matrium carboxymethylcellulose provides a bead polymer in which only 74/0 of the beads have a particle size of 0.5 to 0.9 and only 27 % of the beads have a particle size of " 0.63 to 0.8 mm.

Example 4

In the apparatus described in Fig. 1, a solution of 86 parts of styrene, 8 parts of divinylbenzene, 5 parts of ethylstyrene, 1 part of azoisobutyronitrile and 3 parts of hexamethylene diisocyanate through the nozzle 2 (inner diameter: 0.35 mm, capillary material: stainless steel) at room temperature injected at a rate of 2.3 ml / min. The continuous phase is a 0.5% aqueous solution of polyvinyl alcohol at a temperature of 22 ° C. This continuous phase is fed through 3 at a rate of 8.5 ml / min. Through the feed line 4, an aqueous solution containing 12 -.% Sodium carbonate and 8 wt -.% Hexamethylenediamine contains "at a rate of 2.2 ml / min, respectively. Both the atomization region 6 and the isolation region in section 7 of the reaction column 1 are kept at room temperature. The capsule dispersion exiting at the outlet is transferred to agitator vessel 10 where it is washed with water at room temperature. Subsequently, the aqueous suspension is stirred for 10 hours -at 70 ⁰ C for the polymerization of the polymerization mixture contained in the capsules.

06/29/1982

AP C 08 F / 237 380/8

3 7 3 8 0 8 " ³² " ^{δ0 435 / ΐ1}

The encapsulated, gel-shaped bead polymer of divinylbenzene-crosslinked polystyrene obtained thereon is then converted, without prior removal of the capsule wall, by sulfonation in a known manner into a strongly acidic cation exchanger.

The grain size of the acidic cation exchanger (Na form) thus obtained is "in the range 0.8 to 1.2 mm, 81 % of the beads have a particle size in the range 0.9 to 1.1 mm.

The usual: Perlpolymerisation of the same Polymerisa-, tion mixture in 0.2% aqueous sodium carboxymethylcellulose fleet with subsequent sulfonation, however, provides a strongly acidic cation exchanger, in dam only 53 % of the beads have a particle size of 0.8 to 1.2 mm and only 29 % of the beads have a grain size of 0.9 to 1.1 mm,

Example 5

In the apparatus described in Fig. 1 is formed by capillary nozzle 2 (inner diameter: 0.35 mm, capillary material stainless steel) a 40 C warm solution of 85 parts of styrene, 8 parts of divinylbenzene, 5 parts of ethyl styrene and a part dibenzoyl peroxide with a Injected at a rate of 2.4 ml / min. The continuous phase is an aqueous solution containing 1 part by weight gelatin (pig skin gelatin), 1 part by weight. the "mixture described in Example 6 of U.S. Patent No. 4,181 639 of an acrylamide / maleic anhydride copolymer and its hydrolysis product and 0.05 Gevv" -% purified Natriumcarboxyraethylcellulose (viscosity after Brooksfield 650-850 cP in 2% solution at 20 ± ger ⁰ C and 20 rpm). These contin-

373 80 8 -

29.6.1982 J

AP C 08 F / 237 380/8

33 - 50 435/11

The secondary phase has a temperature of 45 C and a pH of 5.3 and is metered through the feed line 3 at a rate of 5.1 ml / min. The cardio

region 6 is kept at a temperature of 45 C "Through the feed line 4 0.1 normal hydrochloric acid is supplied to the extent as is required to maintain the pH \ iV _e rt the continuous phase to 3.9 (+/- 0,1) to reduce *

In the encapsulant of the section 7, the temperature of the continuous phase is controlled to "DAB it drops of 45 ⁰ C (at the bottom) to 15 C (the upper end)" Oer section 8 is cooled with ice water so that the effluent at outlet 9 Capsule suspension at a temperature of 5 C in the agitator tank 10 passes. In addition, the reaction column 1, the supply line continuously 12% formalin solution at a rate of 7.5 ml per liter at outlet 9 expiring capsule suspension and as much 15 / oige sodium hydroxide supplied that derp.H value in section 8 .11, .5 is.

When the agitator tank 10 is filled, the feed is interrupted and the outflowing capsule suspension is directed to another stirred tank »

In the filled agitator tank 10, the aqueous phase is drained and replaced by a solution of 10 g disodium hydrogen phosphate Oodekahydrat / 1 water.

Subsequently, polymerization of the polymerization mixture enclosed in the capsules is effected by stirring the aqueous suspension at 70 ^° C. for 10 hours.

The encapsulated gelatinous bead polymer of divinylbenzene-crosslinked polystyrene obtained in this manner is subsequently separated from the aqueous phase, washed, dried and then, without prior removal of the capsule wall, by conversion in a known manner in a strongly acidic catalytic converter ,

The grain size of the cation exchanger (Na form) thus obtained is in the range 0.8-1.2 mm; 72% of the beads have a particle size in the range 0.9-1.1 mm.

The customary bead polymerization of the same polymerization mixture in 0.2% strength aqueous sodium carboxymethylcellulose liquor with subsequent sulfonation, on the other hand, gives a cation exchanger in which only 50% of the beads have a particle size of 0.8-1.2 mm and only 28% of the beads Grain size of. 0.9-1.,. 1 mm / - ,, exhibit.

Le A 20 486

Claims (9)

05/29/1982 AP C OS F / 237 380/8 23/380 8 - ³⁵ " ^{60435 / l1} Erf inciting san saying 1 »Process for the preparation of bead polymers of uniform particle size and uniform quality, characterized in that a) produces droplets of uniform size from the monomer or polymerization mixture to be polymerized by canning into a liquid which is substantially immiscible with the monomer or polymerization mixture and is continuously supplied; b) these droplets of uniform grapevine in said Liquid continuously encapsulated according to per se known methods of microencapsulation either directly with a stable under the applicable polymerization conditions envelope or first with a shear-stable sheath and hardens these shearing stable sheath in a second step continuously or discontinuously to a stable under the applicable polymerization conditions sheath ; c) subsequently polymerizing the monomer or polymerization mixture droplets encapsulated with a shell stable under the applicable polymerization conditions,
with the proviso oi) that the monomer or the Polymerisationsgemiseh dc in the direct current to the continuously supplied continuous phase; 4 ; .. 29.5.1932 AP CS CS F / 237 33C / 3 3 7 3 8 0 8 - 35 - SO 435/11 β) that one carries out the generation of ..Tropf chen and their encapsulation in different areas of the reaction vessel; *.) that process steps a) and b) are carried out in the manner that the droplets do not affect the integrity of the droplets from their generation until their encapsulation. 2. Method according to point 1 ,. characterized in that one avoids the action of forces changing the integrity of the droplets by hydrodynamically transporting the droplets out of the atomization region and through the encapsulation region. 3. The method according to item 1 and 2, characterized by * that one uses for the hydrodynamic transport of the droplets from the atomization region and through the encapsulation region caused by the density difference between droplets and continuous phase movement of the droplets in the continuous PJjgase and the flow movement of the continuous phase , 4. Process according to items 1 to 3, characterized in that when using lipophilic monomers or »polymerization mixtures used as the continuous phase of water or aqueous solutions» 5. The method according to the items 1 to 4, characterized in that one uses as a continuous phase aqueous solutions of hydrophilic colloids. 29,5.1982 7 QP Π Q. AP C 08 F / 237 380/8 ύ / J O UU - 37 - 50 435/11 5. Method according to items 1 to 5, characterized in that one carries out the encapsulation of the droplets of uniform size by coacervation, complex coacervation or by interfacial reaction . 7. Process according to items 1 to 6, characterized in that the encapsulation of the droplets of uniform size by coacervation or complex coacervation as continuous phase uses aqueous gelatin or agar-agar solutions. 8. The method according to items 1 to 7, characterized in that as complex coacervation components gelatin and gum arabic or gelatin and copolymer mixtures of a random random copolymer of acrylamide and maleic acid or maleic anhydride and a copolymer with statistically distributed catches of acrylamide, acrylic acid and maleic acid. 9 »method according to the items 1 to 8, characterized in that are used as monomers monovinyl and / or polyvinyl compounds. 10. The method according to items 1 to 9, characterized in that as monomers styrene, <* - methylstyrene, ethylstyrene, chloroetyrene. Esters, or amides of (meth) I acrylic acid or acrylonitrile, divinylbenzene, divinyltoluene, trivinylbenzene, diethylene glycol divinyl ether, trivinylcyclohexane, octadiene-1,7, heptadiene-1,5, wexadiene-1,5 and / or methacrylic acid esters of polyhydric alcohols used » For this 1 page drawings