DE2327429A1 - PROCESS FOR POLYMERIZATION OF LARGE CHLOROPRENE POLYMERIZED PARTICLES - Google Patents

Description

DR. BERG DIPL.-ING. STAPF DIPL.-ING. SCHWABE DR. DR. SANDMAiR

PATENT LAWYERS
8 MUNICH 86, POST BOX 86 02 45

Dr. Berg Dipl.-Ing. Stapf, 8 Munich 86, P. O. Box 86 02 45

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Lawyer file 25 898 Be / Sch

Monsanto Company
St. Louis, Missouri / USA

"Process for the polymerisation of large chloroprene polymer particles"

Chloroprene polymerizates have been widely used found the Kautsehuk area. However, because of the extreme rapid rates of polymerization of the chloroprene monomers the processes for polymerizing chloroprene monomers are difficult to control, making processes relatively expensive required for production on a technical scale. are borrowed.

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Such methods have complicated rapid polymerization thermal energy control devices. For this purpose, reactors with salt water cooling or with complicated heat transfer surfaces for dissipation were used who developed warmth

In addition to the costs, it is difficult because of the high heat of polymerization, the properties of the chloroprene polymers, im in particular to control the molecular structure and the particle properties. Emulsion methods of formation have heretofore been used small particle used. Such emulsions, known as latices, have heretofore been used extensively for paints and coatings used, which should have chemical resistance. These products usually require a lot small particle size to ensure emulsion stability and dispersibility. Such particles can under Use extremely large amounts of emulsifier to be polymerized.

The chloroprene rubbers are known to be non-flammable and they can be incorporated into preparations, to give them self-extinguishing properties. They can be used as types of rubber in thermoplastic polyblends can be used as the rubber phase to add toughness. Need chloroprene polymers for such uses closely controlled properties of the rubber, in particular the size parameters. Tough polyblends require larger par-

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items as such, by means of the known technical Emulsion processes are produced. Sophisticated technical properties can only be obtained if one uses particles of the correct size that are related to the average particle size and the distribution of the particle size can be controlled. The previously existing procedures have largely proven to be inadequate with regard to these requirements.

Accordingly, an object of the present invention is a reproducible polymerisation process, through which large chloroprene polymer particles with a predetermined Weight-average particle size, hereinafter referred to as particle size according to average weight, and distribution the particle size can be produced.

Another object of this invention is a method with a high degree of reproducibility, through the stable Aqueous dispersions of large chloroprene polymer particles can be prepared which are essentially monodisperse Have distribution of particle size.

It has now been found that the foregoing and related problems can be achieved by a reproducible one Polymerization process for the production of large chloroprene polymer particles with a determinable weight-average particle size and particle size distribution, which can be done in such a way that (1) Forms a polymerization medium using water, an emulsifying agent, and 3098 50/0966 _ „. _

bonds that form a redox catalyst system, the sulfate and contains sulfite radicals and an activation metal ion, mixes,

(2) the materials for forming the polymerization medium can be converted (polymerization medium reaction stage),

(3) then a chloroprene monomer formulation into the medium introduces and disperses, (4) then a compound that provides additional sulfate residues in the medium, introduces and disperses and (5) the resulting dispersions are subjected to polymerization conditions for a sufficiently long time to to polymerize at least the greater part of the chloroprene monomer formulations, whereby large chloroprene polymer particles, dispersed in an aqueous dispersion. -

Although the present invention has not been fully elucidated in theory, it is believed that the effectiveness of the process is dependent on the control of the oligomeric soap that forms during the early stages of polymerization is. It is believed that when chloroprene is polymerized in a redox system, chloroprene oligomers Chains with sulfite and / or sulfate residues are formed with the formation of a soap. Because this soap acts as an emulsifier can serve, it can exert a significant influence on the size of the particles that later emerge from the polymerization process can be obtained. Because the amount of oligomeric soap that will form in situ is unknown or predictable is among the commonly used

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conditions in which the monomer and the catalyst system are fed to the emulsion medium at the same time, the amount of soap can therefore vary from trial or process to process vary, which increases the non-reproducibility of the average particle size and the narrow size distribution results. ' ', _. *

It is believed that the reaction stage that preceded the introduction any monomer is provided, for any reason a more consistent reactivity of the catalyst satorsystems. In the present process, some of the metal ions can be mixed with the emulsifying agent or react the catalyst during the 'reaction stage to form a stable amount of the catalyst components. As well as Whenever the process is running, the reaction stage which is provided according to the present invention has the control of the oligomeric amount of soap that is formed, so that the Process reproducible by controlling the reaction stage will.

The polymerisation medium in which the monomeric formulation is dispersed, contains water, emulsifiers and compounds that make up the redox catalyst system. Normally a buffering agent is also added to the polymerization medium in order to stabilize the p ^ value of the system. the The amount of water that can be used can vary widely so long as it is sufficient to provide an aqueous phase

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for the polymerization reaction is formed. In general, about 60 to 600 parts of water can be used per 100 parts of polymerizable monomer (a ratio of about 0.6 to 6.0: 1.0) and preferably about 100 to 200 parts per 100 parts of monomer (a ratio of about 1.0 to 2.0: 1.0) can be used.

Any of the emulsifying agents commonly used for this type of emulsion polymerization reaction can initially be introduced into the polymerization medium. The ammonium and alkali metal sulfates are long-chain saturated aliphatic compounds with 10 to 20 carbon atoms have proven to be particularly advantageous in the process, such as the ammonium, sodium and potassium salts of decyl, Lauryl, palmityl, stearyl, dodecanoyl, etc. sulfates.

The total amount of emulsifier used depends of course. borrowed both from the total amount of that intended for emulsification Monomers, as well as the .desired particle size. In general, the total amount of emulsifier used can be in the range of about 0.15 to 0.50, and preferably about 0.20 to 0.30 $ based on the weight of the monomers Formulation, lie. In the initial charge to the polymerization medium of step (i) there is generally no Emulsifiers or only a fraction of the total amount used. The amount of emulsifier initially added to the water is generally in the range of from about 0.000 to 0.200 and preferably from 0.000 to 0.15 OyS based

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on the weight of the monomer introduced, the remaining emulsifier with the additional sulfate residue in the Step (4) is added '.

In the polymerization reaction, the ρττ-Υ / ert of the emulsion should normally controlled in the range from about 4.0 to 8.0, for which purpose a buffering agent is introduced because it has been determined became that the best reaction rates are usually obtained when the p ^ value in this Area is held. Any suitable buffering agent, though sodium bicarbonate has been found to be particularly useful, at least in part because of its degradation products for the resulting polymer are harmless. However, there can be other buffers that are relatively inert towards the chloroprene polymer, such as sodium carbonate, ammonium hydroxide, etc., can be used The buffer is the same in the polymerization medium , The point in time at which it is formed.

All compounds can be used to form the redox catalyst system which provide the necessary residues are used and such compounds are known to those skilled in the art. For example the sulfate and sulfite residues can be derived from persulfate-bisulfite and bisulfite-peroxide mixtures. It is point out that each residue is formed separately by the appropriate water-soluble sulfate or sulfate compounds can be or that a remainder in situ from a

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Sulfur compound if, for example, bisulfite peroxide mixtures can be used, can be formed.

All water-soluble peroxides and persalts can be used to supply the sulphate residue, whereby the ammonium, Sodium and potassium persulfates are particularly preferred. The sulfite residue can be replaced by sodium bisulfite, sodium formaldehyde sulfoxylate, Sulfur dioxide, sodium thiosulfite or an organic oxidizable sulfoxy compound such as diethyl sulfite, etc., can be delivered. These compounds should be used in such amounts that they provide the desired Deliver leftovers in the required quantities.

The amount of sulfate residue to be used in step (1) or in the polymerization medium depends on the size of the desired polychloroprene particles. For particle sizes from 0.15 to 0.5 μm, the sulfate residue concentration used is generally in the range of about 0.010 to 0.002 wt,? 6, based on the monomer, and preferably from 0.006 to 0.003 wt. <? o are. If relatively large particles are desired, for example from 0.5 to 1.0 µm, the sulfate residue concentration will generally be in the range of about 0.002 to 0.00001, and preferably about 0.003 to about 0.0001 weight percent, based on the weight of the monomer. In the preferred process for producing particles in the range from 0.5 to 1.0 μm, the emulsifier is completely omitted in step (1) and only added in step (4), wherein

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in the. generally about 0.15 "to 0.50 wt. $ based on the Weight of the monomer, and preferably 0.20 to 0.30 wt. ^ 6 be used.

The amount of the component containing the sulfite group should be selected so that the ratio of the sulfite group to the total sulfate used in steps (1) and (4) is about 1.0 to 15.0: 1.0, and preferably about 3.0 to 10.0: 1.0. Assuming that the total amount of sulfate ions used in steps (1) and (4) is generally 0.01 to 0.10% by weight based on the monomer, the preferred amount of bisulfite ion used in step ( 1) is for use 'are generally in the range of about 0.02 to 1, 5 Gew.fo, based on the monomer, and preferably about 0.06 to 1.0 wt. io.

The redox catalyst system is used in stage (1) as part of the Polymerization medium added. A small controlled amount is added in step (1) to keep them in step

(2) to react and a small and controlled amount of oligomeric soap when the monomers are in the stage

(3) can be added. The chloroprene monomer is low Solubility in water and forms oligomers with the redox catalyst, when it enters the water phase of the polymerization medium. In addition to the oligomers, one is controlled and small amount of oligomeric residues in the water phase educated. These oligomeric residues become insoluble in water

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and enter the monomeric oil phase micelles passing through the oligomeric, soap are formed, creating a controlled Concentration of particle growth starts up. This controlled concentration of the monomer polymer micelles now controls the kinetic conditions of the polymerization such that the polymerization largely takes place in the monomer particle micelles expires. In the present process, these micelles are larger and fewer in number because of the smaller amount of formed oligomeric soap. As a result of this, the rates of polymerization are slower, causing the Control over the usually very rapid polymerization of chloroprene in the usual emulsion process, the large amounts of emulsifier and lots of small polymer ionsmic eil en is possible.

Regardless of theoretical considerations, the polymerization of the present invention carefully controlled in the early stages by using chloroprene oligomers Soaps and chloroprene-oligomer-free residues are used, which means a controlled particle size and distribution of the particle size is achieved. In addition are the rates of polymerization controlled so that a reproducible process is obtained.

Step (2) of the process is critical in that "the ~ ' Redox system has a reaction stage in which the metal ions the catalyst in a controlled programmed stage

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activate, whereby the redox system is stabilized · The persulfate breaks down almost immediately in the early stages, whereby an uncontrollable number of sulfate-free residues "forms. The action stage is provided around this initiation stage to stabilize on a steady state that is controllable. Step (3) brings the monomer into a controlled one Polymerization medium that initiates controlled oligomer growth. In stage (4), additional catalyst is used fed in order to ensure a high conversion of the monomer in step (5), it being pointed out that that the number of polymer particles formed by the existing number of the monomer particle micelleh formed in step (3) is already set.

The monomers can be total or discontinuous or be fed continuously in stage (3). Additional emulsifying agent can be added in step (4) in order to Disperse monomer, thereby giving increased diffusion ratios Monomer to micelles is obtained because the greater part of the monomers present in the monomer-particle micelles is polymerized, resulting in a controlled growth of the particles present and a narrow distribution of the particle sizes receives. In the preferred method, a major part of the monomers are initially fed in in stage (3) and a remainder of the monomer is fed in batchwise thereafter.

The present process can be carried out in the manner

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that aqueous dispersions of Chloroprenepolymerxsatpartikel with multimodal distributions of the particle size, i.e. one in Content of particles of different sizes can be formed by adding aqueous dispersions in an additional stage from uniform distributions of different monodisperse sizes mixes to products with a reasonable Number of species, i.e. different proportions of size, preferably 2 or 3. In general it works Process of this invention in such a way that aqueous dispersions of chloroprene polymer with a certain Percentage by weight of the polymer particles or solids are formed in aqueous dispersions. The mixed ones Aqueous dispersions can be controlled with regard to the solids content and the precise mixing of the Particles are controlled according to weight percentages, whereby any desired multimodal dispersion of particles is obtained. They generally have mixtures of large and small monodisperse particles have great utility in coatings or as rubber phase particles in thermoplastic polyblends. For example, is a mixture of chloroprene polymer particles a first type containing 50 to 95 wt. $ of particles with sizes from 0.2 to 0.5 microns and which is mixed with a second type which contains 5 to 50 wt. jfc particles with sizes from 0.5 to 1.5 microns, the preferred blend used with other thermoplastic polymers Formation of polyblends is used.

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Such thermoplastic poly "blends are produced by that the aqueous dispersion of the thermoplastic polymer, for example polystyrene or SÄN polymers, mixes in aqueous dispersions with the chloroprene polymers described above in aqueous dispersion, whereby a uniform mixture of chloroprene polymer particles and thermoplastic polymer particles is formed. The mixture of particles is carried out from the aqueous dispersion Coagulation, filtration and drying obtained. The thermoplastic Polyblend is also brought to Sehmelz colloid, for example by extrusion, grinding, Banbury mixing or other melt colloidation processes known to those skilled in the art, thereby producing a dispersion of chloroprene rubber particles forms in a solid thermoplastic polyblend.

The chloroprene polymer particles in aqueous dispersion can with monomers of the monovinylidene aromatic compounds, such as styrene or the ethylenically unsaturated nitrile types such as acrylonitrile are mixed and then grafted with the monomers, whereby grafted chloroprene polymer particles are obtained which are dispersed in the thermoplastic polyblends can, thereby obtaining physical and technical properties of great utility.

So that the hedox catalyst system takes over exactly its function, it is also essential that trace amounts of

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Activation metal ions are present. This metal can be such as is generally known to the person skilled in the art, such as, for example, iron, copper, chromium, etc. Often it is it is not necessary to add the metal ion as a separate component because sufficient amounts are usually trace- impurities are present in the »vas & er, which is for that Polymerization medium can be used. However, for some reasons, it is of course desirable to use highly purified or to use deionized water, in which case it may then be necessary to introduce activation metal ions separately. ''

After all of the above-mentioned constituents have been mixed and such other materials have been introduced according to V / ung, the medium obtained is heated to a temperature in the range from 40 to 60 ^° C. and in particular in the range from 50 to 58 while charging, usually under a vacuum ⁰ C heated. The duration of the reaction step can vary widely, but is generally at least about 10 minutes. A time of 3 hours is a practical upper limit. Normally, a reaction step time of less than one hour is sufficient and the preferred time is 15 to 45 minutes. It should be pointed out that the criterion on which the initiation or reaction is based consists only in the formation of a catalyst system with a reactivity which is stabilized in such a way that it is

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Maintaining a similar reaction stage can be reproduced can.

After completion of the Eeaktionsstufe -be polymerizable monomeric formulation introduced into the medium and dispersed. The monomer feed can be carried out all at once or also be fed batchwise or continuously. In the preferred process, a fairly large batch is used initially and the remaining monomer was added discontinuously thereafter. The conditions in the reaction vessel are if necessary, adjusted so that a suitable environment is formed for the polymerization of the monomer to proceed becomes "A temperature" of about 30 to 65 C and autogenous pressures are maintained. In the reaction vessel can also Pressures above the autogenous pressures, for example such high pressures such as 11.5 kg / cm (150 psig) can be used. The preferred one The polymerization temperature is in the range of about 50 to 60 ° C.

The reaction is continued until about 60.0 to 98% of the existing monomeric formulation are converted into the polymer and preferably up to 70.0 to 94.0 $. this requires a polymerization time of about 2 to 14 hours and preferably about 3 to 10 hours. After the desired degree of conversion has been achieved, the polymers become atparticulate separated from the reaction medium by conventional methods, washed and, if desired, dried. However, since

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If the process is aimed at providing polychloroprene polymer particles with a particularly large size, the process is ended when the particles are present in an aqueous dispersion while maintaining the integrity of the particles. The aqueous dispersion of the polychloro orene particles can then be treated at elevated temperatures under vacuum in order to remove unpolymerized monomers and the polymer particles can be stabilized with a dispersed stabilizer such as phenylnaphthylamine, thiuram sulfide or other antioxidants to ensure crosslinking or to prevent degradation in the unvulcanized state. Such stabilizers are generally used in amounts of 1 to 2 ° or less, based on the weight of the polymer, depending on the degree of stabilization desired.

The aqueous dispersion obtained can be used directly for obtaining the rubber from the dispersion or for mixing with it other aqueous dispersions of other polymers can be used to form polyblends. Such chloroprene polymer particles can be grafted in aqueous dispersion, including other monomers such as styrene, acrylonitrile or other ethylenically unsaturated monomers or dienes are added to the dispersion and the polymerization is carried out in the presence the chloroprene polymer particles make. The grafted particles are stabilized and are usually crosslinked in such a way that that they when used with other thermoplastic materials

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Subjected to enamel colloidation processes, as ge. separated phase, with the formation of polyblends with high impact resistance will disperse. Due to the incorporation of the chloroprene polymer particles, these polyblends are fire-retardant and eliminate electrostatic charges, which increases their usefulness. .

Modifiers or chain transfer agents can be used in the Monomer formulation can be used to control the molecular weight of the chloroprene rubber. To this end you can various materials, for example mercaptans, disulfides, Terpenes, sulfur and amines can be used. Most preferred are mercaptans, for example normal and tertiary octyl, decyl and dodecy! mercaptans., in relative small weight percentage »such as 0.001 to $ 1.0 based on the weight of the monomer.

. The monomer formulation may be up to 2 wt f <> crosslinking agent ,,: based on the Ghloroprenkautsehuk forming monomer or monomers, if one a crosslinked rubber wishes * The crosslinking agent may be any of the agents which are geeigrieterweise used for crosslinking diene rubbers , for example Divdny! benzol ,. Divinyl ethers, divinyl sulfides, diallyl maleate, allyl erylates and the like "

Although the invention has been described in terms of chloroprene it is also applicable to Ilischpolymerisate, in which

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Chloroprene at least 50% by weight of the copolymer and preferably at least 80.0 wt. To the materials, copolymerized with chloroprene by the process of the invention include conjugated 1,3-dienes, for example butadiene, isoprene, piperylene, etc., monovinylidene aromatic monomers, for example styrene, arylhalostyrene, Aralkylstyrenes, alpha-alkylstyrenes, for example alpha-methylstyrene, o-, m- and p-chlorostyrene and methylstyrene, etc., Ethylenically unsaturated nitriles, for example acrylonitrile, methacrylonitrile, etc., alkyl acrylates, for example methyl acrylate, etc., alkyl methacrylates, methyl methacrylate, etc., alpha-olefins, for example ethylene, propylene, etc., vinyl esters, for example vinyl acetate, etc., vinyl and vinylidene chlorides and bromides, and the like.

The following specific examples are presented to illustrate the effectiveness of the present invention, all of which Parts and percentages are by weight, unless because that this is stated otherwise. It is clear that many Modifications to the method according to the invention can be made without deviating from the inventions.

example 1

About 150 parts of 54 ⁰ C v / lean water are introduced into a reaction vessel with stirring together with 0.1 part of sodium bicarbonate and 0.15 part of sodium bisulfite. Vacuum the jar for about 20 minutes, after which time about 0.002 parts of potassium persulfate

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be added slowly. After the addition has ended, the vessel is again taken under vacuum and the polymerization medium is kept at about 54 ^° C. and allowed to react for about 15 minutes. 100 parts of chloroprene monomer is then dispersed in the polymerization medium and bringing it to 5O ⁰ C and autogenous pressure. About 0.013 part of sodium lauryl sulfate and about 0.02 part of potassium persulfate are dissolved in 50 parts of water and introduced into the medium and dispersed. The dispersion obtained is subjected to ^{polymerization for four hours at 50 °} C. and autogenous pressures. After completion of the reaction, excess monomer to be drained under vacuum at 6O ⁰ C and the ChIoroprenkautschukpartikel in the aqueous dispersion gemassen in particle size. A "Model 3000 Particle Size Analyzer" from the Martin Sweets Company, Louisville, USA was used in connection with the method of Groves et al., "Size Analysis of Subsieve Powders Using a Centrifugal Photosedimentometer", British Chemical and Engineering, 9: 742-744 ( 1964) used. When determining the particle size based on average weight, the density of the polychloroprene particles was 1.32 g / ccm. The average particle size of the particles formed was 0.610 µm. .-.-.-

Various procedures were carried out according to Example 1 carried out, whereby one particle sizes according to average weight of 0.606, 0.598, 0.600, 0.619, 0.614 and 0.611yum received, from which it can be seen that the mean deviations

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are of mean less than 0.010yum.

Example 2

The procedure of Example 1 was repeated except that 0.17 part of sodium lauryl sulfate was added in the polymerization medium in step (1) and 0.10 part of dispersant containing the sulfate residue in step (4). The particle size, according to. Average weight was about 0.200 yum. Various methods have been expiration performed, which indicated that a good control of the particle size in the range of about • - was 0,010yum possible.

Example 3

The procedure of Example 1 was repeated except that the reaction step for the polymerization medium was not was used and the vinyl monomers were introduced into the polymerization medium immediately before the redox system had implemented. Various procedures have been carried out on this basis and the particle size according to the average weight was 0.550 or 0.531, 0.622, 0.601, 0.592, 0.623 and 0.595 µm in diameter. The particle size according to the average weight was accordingly 0.550 to 0.623 μm or a deviation of 0.073 μm between the individual Process, which is to be regarded as relatively poor reproducibility of the particle size, if a controlled particle size is critical for end-use properties.

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Example 4

The procedure of Example 1 was essentially repeated, 95.0 parts chloroprene and 5.0 parts acrylonitrile were used as the monomeric formulation. Through different Processes found that the particle size by weight average as in Example 1 in the narrow range the particle size was reproducible. .

Example 5

The procedure of Example 1 was followed except that 0.006 part of sodium lauryl sulfate was dissolved in the polymerization medium of step (1). The particle size by weight average was about 0.40 µm. Various methods have been performed expiration and it was found that the particle size within - was reproducible to 0.01 /.

Example 6 '

About 800 g of stable aqueous dispersion of chloroprene polymer particles, prepared as in Example 2, with a monodisperse Particle size according to average weight of 0.2 yum j the particles forming about 33% by weight of the aqueous dispersion, was placed in a reaction vessel kept at 23 ° C was held while the dispersion was stirred. About 200g of a second stable aqueous dispersion of chloroprene polymer particles, v / ie made in Example 1, with a

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monodisperse particle size based on average weight of 0.6 μm, the particles forming about 33 wt. ^ of the aqueous dispersion, was mixed with the first aqueous dispersion with stirring for a sufficient time that a uniformly stable aqueous mixed dispersion of the chloroprene polymer particles with a "multimodal ¹¹ distribution The particles were measured with regard to the distribution of the particle size by the measuring method as used in Example 1, and a bimodal distribution was found, with 80% by weight of the particles as a monodisperse form with a particle size based on average weight of about 0.2 μm and 20% by weight of the particles were present as a monodisperse form with a particle size according to average weight of about 0.6 "μm. It was found that the particles were present as separate individual particles in the stable mixed dispersion without any substantial agglomeration of the small and large particles with a change in the bimodal distribution, which results in a stable aqueous dispersion of polychloroprene polymer particles with a multimodal distribution of the particle size was obtained, which was excellently suited for mixing with thermoplastic polymer particles with the formation of polyblends.

■ patent claims

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Claims (14)

" ²³ " · - 2327A2-9 Patent claims: Ii reproducible polymerization process for the production of large particles of chloroprene polymer with a * predetermined weight-average particle size (particle size according to average weight) and distribution of the particle size, characterized in that (1) a polymerization medium is formed, including water, an emulsifier and compounds containing a Redox catalyst system of sulfate and sulfite radicals and an activating metal ion form, (2) the materials in the reaction medium can be converted, (3) a chloroprene monomeric formulation is introduced into the medium and dispersed, (4) a. Compound which makes further sulfate residues in the medium available, introduces and disperses and (5) subjects the resulting dispersion to polymerization conditions for a sufficiently long time to polymerize at least the main part of the chloroprene-monomeric formulation with the formation of large chloroprene polymer particles which are dispersed in a dispersion . 2. The method according to claim! Characterized in that the chloroprene polymer particles a Have particle size distribution that is monomodal and that is weight-average particle size is about 0.10 to 2.0 µm. / 0ä6b 3. The method according to claim. 2 characterized in that the monomodal distribution of the particle size is essentially monodisperse. 4t method according to claim 1 characterized that the aqueous dispersion of the polychloroprene polymer particles with a particle size n-ach average weight of about 0.1 to 0.5yum further with a second preformed aqueous dispersion of chloroprene polymer particles with a particle size according to average weight from about 0.5 to 2.0 / µm, whereby one an aqueous dispersion is obtained which is a multimodal mixture of the chloroprene polymer particles and the second aqueous dispersion less than 50% by weight of the total weight of dispersed particles. 5. The method according to claim 1, characterized in that the chloroprene-monomeric formulation Chloroprene monomer or a formulation used containing at least one material that interacts with the chloroprene monomer in an amount less than 50 wt. ^, based on the weight of the monomeric formulation, copolymerizable. is. ' 6. The method according to claim 1 d, a by gekenn-ζ e \ i c h η e.t that the polymerization conditions 3 Ü 9 Ö ο Ü / U 9 bb of step (5) the rate of chloroprene polymerization further controls that a substantial part of the chloroprene polymer particles sizes in the range of about 0.3 to 0.8 yum. 7. The method according to claim 1, characterized in that that as the polymerization medium of the stage (1) Water is used in an amount sufficient to give a ratio of 7 / water to polymerizable monomers of about. 0.6 to 6.0: 1.0, the emulsifier is mixed in an amount of 0.0 to 0.2 $ based on the weight of the monomer and compounds that form the redox catalyst system, mixed in in amounts sufficient that about 0.00001 to 0.006 ^ sulfate residues and about 0.02 to 1.5 $ sulfite residues, both based on the weight of the monomeric formulation, are available » 8. The method according to claim 7 characterized by that the sulfate residue is replaced by an ammonium salt and alkali metal persulfates and the sulfite radicals introduces an "alkali metal bisulfite, where, the metal ions as trace impurities are present in the water 9. The method according to claim 1, characterized in that that an amount of emulsifier, which is added before the end of the polymerization, of about 0.15 up to 0.50 wt., based on the weight of the monomeric formula -26- 3Ü3BBQ / Ü96V lation, used. 10. The method according to claim 1, characterized in that the greater part of the emulsifier with the sulfate residues is introduced in step (4), the emulsifier used as ammonium and / or alkali metal salts of organic compounds having 10 to 20 carbon atoms and that polymerization conditions are used , the autogenous pressures and temperatures in the range between about 30 and 65 ⁰ C and that the polymerization reaction is continued for a sufficient time to polymerize about 60 to 98% of the chloroprene monomer formulation. 11. Stable aqueous dispersion of large chloroprene polymer particles with a water to polymer ratio of 0.6 to 6.0: 1.0 d a du rch geken n'z e i c h η e t, that the polymer particles are essentially "in a monodisperse distribution of particle size and that the chloroprene polymer is a copolymer of chloroprene with at least one comonomer, which is with the chloroprene in an amount less than 50% by weight based on the weight of the Copolymer, is copolymerizable and that the distribution of the particle size is uniform with a particle size by average weight from about 0.15 to 2.0 µm. 12. Stable aqueous dispersion of large chloroprene polymer -27- 3 0 y 8 b Ü / U 9 6 b ■■. -27- · - 2327423 Sat particles according to claim 11, characterized in that they are not included indicates that the distribution of particle size is multimodal, with a first type being a particle size from about 0.15 to 0.5 µm and a second type has a particle size has an average weight of about 0.5 to 2, oyum. 13 · Stable aqueous dispersion of large chloroprene polymer particles characterized according to claim 11 that the aqueous dispersion with 0.150 to 0.50 wt. ^, based on the weight of the chloroprene polymer particles, Ammonium or alkali metal salts of organic compounds containing 10 to 20 carbon atoms is stabilized. 14. Stable aqueous dispersion of large chloroprene polymer particles according to claim 11, characterized in that the aqueous dispersion has a Ρττ value of about 4.0 to 9.0, the p "-" iVert through Penetration of a. Buffer of an alkali ime t allb ic ar b onate s, an alkali ime t al lc ar b onate s and / or ammonium hydroxide controlled is.