DE1074264B - - Google Patents

Description

GERMAN

It is known that polymers are styrene compounds many uses as shaped articles which can be formed by conventional methods, _e wi by compression molding or injection molding. The molded products are transparent u _n d possess good notch toughness and tensile strength as well as gate electrical properties. Polymers of styrenic compounds, especially the alkylstyrenic polymers substituted in the ring, have increased strength and resistance to heat, chemical influences and abrasion. In the polymerization of styrene compounds, it is generally difficult to obtain a good product, when monomers of relatively low purity, ie, for example of 50%, polymerized by conventional methods to give a low resistance against heat ¹ S and a tendency to crack from the presence of non-polymerizable contaminants. Examples of such impurities present in the monomers are e.g. B. ethylbenzene in styrene and ethyltoluene in methylstyrene. Furthermore, the polymer changes color when the unreacted monomer is to be removed from the polymer of the styrene compound by known methods, at the high temperatures developed in this way.

The key according to the invention ^a resulting advantages are a 5 polymerizing monomers of low purity, the convenient method, a continuous operation and the possibility of eliminating an uncontrollable heat generation during the reaction. According to the invention it is possible to obtain transparent polymers from styrenic compounds which are beautiful in color and contain less than 2% methanol extractable and generally less than 1% methanol extractable. By methanol extractables is meant the amount of material which can be removed from the polymer by dissolving the polymer in solvents such as benzene, toluene, dioxane, and the like, pouring the resulting solution into methanol and filtering off the precipitate. The weight difference between the original polymer and the precipitated polymer is called the methanol extractable.

According to the present invention, these high polymer homopolymers are obtained by using a simple apparatus and using a technique in which it is possible to use a continuous process. Furthermore, as mentioned above, it is not necessary to use a monomer of high purity in order to achieve good results, but this is also possible with monomers of low purity. Another benefit of the present invention is that it enables a shortened polymerization cycle. According to the invention, polymers of compounds become methods of manufacture
thermoplastic polymer

Applicant:

American Cyanamid Company,
New York, NY (V. St. A.)

Representative: Dr. F. Zumstein
and Dipl.-Chem. Dr. rer. nat. E. Assmann,
Patent Attorneys, Munich 2, Bräuhausstr. 4th

Claimed priority:
V. St. v. America March 30, 1956

James Anthony Melchore, Darien, Conn. (V. St. Α.),
has been named as the inventor

Obtained of the styrene type, optionally without the need to add a catalyst.

The present process for the polymerization of monomers of the general formula

C = CH ₉

where R is hydrogen, chlorine or methyl, R 'is hydrogen, chlorine, a lower alkyl, a lower alkoxy or a cyclohexyl radical and η is an integer between 0 and 2, is mainly characterized in that the monomers at one Temperature of about 85 to about 120 ° C until a polymerized mixture is formed with a content of not more than about 70% of polymeric material polymerized, that thereupon the partially polymerized mixture, which still contains unchanged monomeric material, by a combined extrusion and evaporation device, which is maintained between about 110 and 225 ° C and at an absolute pressure of less than 200 mm of mercury, is passed within less than about 5 minutes, wherein the polymeric material is pressed out and at the same time the monomeric material is evaporated that the volatilized monomers to a residue of polymeric material

909 727/528

3 4

rial of more than 98% and the remaining in a twin screw press combined with

polymeric material is pressed outwards. - Filled in an evaporation device. The com-

Special embodiments are combined in the subclaims expressing and vaporizing device

protected. heated in sections to about 110 to 225 ° C and

Under styrene compounds according to the invention 5 under vacuum at an absolute pressure of approximately According to the method, styrene per se, 5 to 200 mm of mercury as a core substance, is preferably used tuierte alkylstyrenes, such as o-, m- and p-methylstyrene, temperature of the combined heated sections 2,4-dimethylstyrene, p-tert-butylstyrene and the like; Alkoxy expressing and vaporizing device at approx styrenes such as p-methoxystyrene; ring-substituted styrenes, 160 up to 200 ° C and the vacuum preferably at such as p-cyclohexylstyrene; Nuclear-substituted halostyrenes, about 30 to 110 mm of mercury absolute pressure such as chlorostyrene, 2,4-dichlorostyrene, 2,5-dichlorostyrene and the like; held. When the partially polymerized mixture is made in the side chain alkyl- and halogen-substituted styrenes, the cooling coil in the combined squeezing and handling α-chlorostyrene and the like. Mixtures of the damping device is filled, causing the Styrenic compounds can also, if desired, increased temperature and the heat used in the beverage be e.g. B. a mixture of methyl 15 working of the polymer with the twin screws of the styrene and α-methyl styrene. combined extrusion and evaporation device

It can be a common polymerization catalyst that is developed, a volatilization of the volatile

such as a benzoyl peroxide, in a proportion of approximately the constituents of the partially polymerized material

0.02 to 2 percent by weight, based on that in the reactor in the cooling coil zone, and at the same time, since the

used monomers. Other 20 combined squeezing and vaporizing devices

useful catalysts are e.g. B. tert-butylhydro- is kept below normal pressure, which is unchanged

peroxide, tert-butyl perbenzoate, ditert-butyl peroxide, derte monomers and other volatile material from the

Lauroyl peroxide and the like. Also mixtures of these cata- the polymer-containing material are withdrawn or

analyzers can be used. It is necessary that it evaporates. During this operation, the purity of the

Use of a catalyst to carry out the 25 polymers brought to 98 ° / ₀ and higher.
Polymerization according to the present invention does not. Treatment in the combined squeeze and

According to the invention, a common pretreatment evaporation device is initially very advantageous because that lung pot used. The feed of material to be polymerized, e.g. B. the unreacted monomer rendem monomers, such as methyl styrene, is filled into the filling from the combined expressing and evaporation chamber. The polymerization is carried out at 85 to 110 ° C, depending on the proportion of diffusion from the polymer began. The agitation of the mixture depends on the material and because this removal is customary Paddles or stirrers completed. Having homely is a very slow process, especially at about 4 to 24 hours of treatment in the pre-viscous styrene-type polymer which is relatively treatment pot, the mixture reaches a transformation that is highly cross-linked. With the combined extrusion and of about 65%, the polymer, although there is 35 evaporation section of the process being the polyviscous is to be stirred further. It is possible to mix mers and monomers under vacuum in this way not expedient, the conversion continues in that constant and very fast new surfaces Perform pretreatment pot, since the viscosity of the in the vacuum sections, are formed, the Mixture is so great that the agitation of the same with the non-polymerizable compounds and / or unusual Institutions becomes more and more difficult. 40 polymerized polymerizable monomer from the From this point in the conversion the monomer mixture will be removed. Through this technique, from results in the risk of the reaction running away, the diffusion fraction is so improved that almost 100% of the with consequent formation of a product of non-polymeric material from the remaining poly is desired low molecular weight. The polymer meren can be removed and thus a practical and is now to be created in a combined extrusion and evaporation 45 new process.

device in which the purity of the material introduced Polymers up to about 99% by eliminating those unchanged in the combined extrusion and evaporation Monomers increases. It is recommended that a direction that has a polymer content of no more than that the monomeric material has from about 20 to 45% about 70% is less than about Conversion in the pretreatment pot pretreated 50 5 minutes and usually 1 to 3 minutes to generate and thereafter the pretreated polymer into one of a material greater than 98% and generally Cooling coil running in which the polymer conversion is greater than 99% of polymer. It should be noted that the up to about 70%, but preferably not more than 65%, combined expressing and vaporizing device Conversion is carried out. After the poly- not to drive the polymerization reaction merization was effected during this time, the 55 is used, but to remove the non-um material in the combined extrusion and evaporation set material, both the non-polymerizable device where the complete polymerisation of the compounds as well as the polymerisable niciit Material according to the invention is carried out, polymerized compounds from the mixture. By guided. Limiting the polymerization to this simultaneous squeezing and volatilization of the partial low degree of conversion is a main characteristic of the polymerized mixture in the cooling coil area the invention. has been obtained, there is again the risk of

The material can be introduced directly from the pretreatment pot at the temperature at the critical period which results in the combined squeezing and evaporation device due to the exothermic reaction, since the polishing, but it is advisable to use the monomer conversion of approximately 25% conversion of monomers to polymerize in two stages, ie in the pretreatment pot up to about 45% conversion accompanied by a strong increase in viscosity and is avoided. In accordance with the present invention, up to about 70% conversion can be achieved in the cooling coil. this can be done even though the heat transfer The mixture, which contains approximately up to 70% solids of the styrene-type polymer, is in the range of, that is, at the point at which the polymerization is 0.07 2 · 10 ~ ^e g cal / cm ² / sec / 0 ° C / cm and the heat reaction according to the invention is completed, will be 70 dispersion especially in cross-sections over 5.08 cm

runs continuously with the serpentine thread from the highly viscous reaction mass. Liquid to regulate the Increase in conversion is made more difficult, even at temperature in the cooling coil zone, can be caused by agitation. different ways circulate. As shown, the cooling die occurs unchanged monomeric compound emerging from the liquid in the shaft 19 of the cooling coil at 20, Charging in the combined extrusion and discharge 5 falls down through the hollow thread 17 and occurs at 21 the damping device has been removed, can be used in advance. The path of the coolant can also be reversed treatment pot can be returned. When they become unclean. Flexible couplings to connect the Monomers can be the volatilized material in all the lines for the cooling liquid with the cooling source ■ or partially withdrawn and removed from the system are shown at 22 and 23. The coupling 24 for the remote part can be used as an additional product. Mono-io cooling coil shaft and the cooling liquid line mers of only 50% purity can be polymerized. can in the usual way via the gear 25 by not However, it is preferred that the moving means shown be rotated to the volatilized material, which was reinstated in the continuous process. It can be seen that the partially polymerized is to be set so that the filling constant and a material directly from the pretreatment pot 1 into the polymerizable monomer material of the purity of 15 cooling vessel 39 for the combined extrusion and processing 90% monomer is retained. This damping device can be introduced, however make it necessary that some of it be recirculated for economic and practical reasons brought material, which is preferable from the combined extrusion, the pretreated material in a second and evaporator has been withdrawn to polymerize from stage, i.e. in cooling coil zone 12 is performed, the proportion of the original ao before the introduction of the partially polymerized material The purity of the monomer depends of the monomeric starting material becomes the tung27.

volatilized material preferably e.g. B. by Destil- The up to 70% conversion polymerized material ! ation is purified and the monomer is recovered and is recovered from the bottom of the cooling coil zone through the loop introduced into the system. 25 device 26 in the double-wound combined extrusion die to produce an almost pure polymer, e.g. B. and vaporizer 27 introduced. The kombitnit greater than 98% purity, time required, through ned squeeze and vaporizer shaft 28 the present method is greatly degraded, and further is associated with rotating means not shown Advantages are lower end price, convenience and and lies in a housing 29 with gear, which the wide range of applicability of the monomers of 30 screw thread 30 "rotated. Various in the drawing Purity. tion is only given a screw, but it is clear, the invention is based on the drawing, which one that the combined Auspreß- and Verdampfungsvorrich-Teilschnitt shows are explained in more detail. Only for device 27 contains two snails, which are arranged side by side the polymerization of methyl is supposed to be ordered and normally in opposite directions ■ styrene are described. 35 move direction. To the combined extrusion and In the drawing, 1 is the pretreatment pot with evaporation device around there is a heating one rotatable rack or stirrer 2, with the jacket, which is divided into two sections, as indicated at 31, Shaft 3 is connected, this disintegrating through a sleeve 4. The inlets 32, 33 and 34 allow the Zirkuan the top of the pot runs, and through the gear 5, lation of the heating fluid in the heating jacket sections ■ which is connected to a motor, not shown, 40 of the combined squeezing and evaporating device driven will. The pot is heated in the usual way, which is at a temperature of 160 to 225 ° C this is indicated by the jacket 6. The heating will hold. The heating fluid comes out of the heating jacket liquid, such as oil or other suitable material, taken through the connections 35, 36 and 37, the flows into the jacket at 7 and flows through line 8 connected to line 38 which carries the liquid the end. The monomeric methyl styrene is returned to the pot under 45 to the heating source, not shown. the Pressure introduced through line 9. When entering the feed, it enters the double-wound expressions Monomers is added to the heated pot on a tempering device through the feed vessel 39, and the polyperatur held at 85 to 110 ° C, the rotating merized material, which in the form of filaments 40 Stell 2 keeps the monomer moving while it is shown through is from the spray vaporizer about 60%, but preferably up to 45% of the conversion is removed by the extrusion die 41. The partial polylation polymerized in 6 to 24 hours. The partially merized mass runs through the filling vessel 39 over the polymerized use in this first stage is after IQ extrusion device, in which the volatile substances, pumped, but can also be caused by pressure and / or gravity due to the increased temperature and the decreased force set in freedom through the bottom of the pot via line 11 pressure in the squeezing device either directly into the feed container 39 of the grain 55, escape through the opening 42 and 43. That Combined extrusion and evaporation device (polymerized material runs through the extrusion mold 41 a line not shown) or, as shown within 1 to 3 minutes after entering the kombige, into a second polymerization zone or stage, nated extrusion and evaporation device. The polyim hereinafter referred to as the »cooling coil zone« ·, merged mass that runs through the extrusion mold 41, occur, which consists of a boiler with cooling jacket 13. 60 can by the rotating arms attached to the shaft 46, The coolant for the jacket enters at 14 and at 15 which is driven by means of a motor, not shown, the end. The cooling coil zone is attached to a cooling coil 16, to be cut into tablets. Of the provided with a hollow thread, which is so called because the condenser 47 is connected to the pot 1 through the lines 48 Thread or arm 17 is hollow and the circulation and 49 connected. Part of the vaporous monoeiner Cooling liquid allowed in it. To a stronger 65 meren in the upper sections of the pot 1 can through Mixing of the material to be polymerized to circulate the line 48 via the condenser 47 and as allow the cooling coil to be threaded back to the pot through line 49 with a reverse fluid 18 be provided, d. H. an arm that turns on the. Lines 50 and 51 are for circulation Periphery of the serpentine thread 17 is attached, a conventional coolant around the condenser 47 in front However, the direction of the winding is reversed to that of the cooling 70. As indicated, the volatile material is in

i U / 4 2

7 8

the double combined squeezing and evaporation The process is also characterized in that

device through the openings 42 and 43 through which a polymerization of higher conversion does not lead 52 and 53 removed, which is necessary with the line 54 and so the risk of a tip in the exovefbunden over which part of the volatilized thermal stages is avoided. This is special Material can be branched off, as shown in FIG. 44, to 5 advantageous because of the difficulties of continuous a constant degree of purity in the monomeric polymerization at higher conversions. After this Material introduced at 9 to maintain. present process the purity of the polymer, As a result of the prevailing at the opening 42 and 43 the monomer contains only 50%, through the vacuum the volatile material flows out of the partial volatilization of the unchanged material device 54 to the condenser 55, where the volatile material io polymerized mass achieved. In the case of such is condensed and via line 56 to the supply low purity of the material, d. H. of mixtures, vessels 57 or 58 flows. Compounds 59 and 60 are only about 50% polymerizable monomers By circulating a common coolant around the hold, it is possible to prevent the polymerization of the condensers55 intended. Valves 61 and 62 are up to about those polymerizable monomers Regulation of the flow of the condensed monomer 15 to carry out 100% conversion, since as a result of the Veraus the condenser 55 is provided. When the valve 62 impurities in the mixture the viscosity is just at is open, the valve 61 is closed, and vice versa. 100% conversion of polymerizable monomers When valve 62 is open, the condensed mono- will not experience the high degree of polymerization under Bemere flow into the container 58. The valve 63 is achieved equal use of purer polymeric mixtures, closed early. The valve 64 is then open so that 20 The non-polymerizable material is then from the a vacuum via line 65 by means of a non-polymerized material in the combined press-out vacuum pump, which is connected to line 66 and removes evaporation device, is, is made. The prevailing in line 66 The following examples are to explain the invented

The vacuum is so great that the method according to the invention in the condenser container is indicated, according to which a poly- and the connecting lines that lead to the openings 42 25 merized product with a high yield of poly- and 43 lead, prevailing vacuum a size of 5 to merem material by simultaneous pressing and Ver-200 mm and preferably from 30 to 110 mm of mercury vaporization of the polymeric content is achieved. The speabsolutem Pressure owns. If the container 58 with the specific configuration of the details is not intended to be filled as condensed liquid monomers, this will be considered as a limitation; the parts are parts by weight. Valve 61 open and valve 62 closed. Equal to 30 unless otherwise stated At the same time, valve 67 is opened and valve 64 is opened

closed so that the vacuum through line 66, by example ^

Line 68 to the container 57, the condenser 55, the 650 parts of styrene are in a stainless steel kettle

Line 54 and the openings 42 and 43 arrives. The steel filled. The mass is heated to 110 ° C (85 to 130 ° C) Valve 69 is closed when the liquid monomer 35 is heated until the viscosity is about 80 poise (i.e., 35 poise) is withdrawn in the container 57. If the container has 57 to 40% conversion of monomer to polymer) for the collection of the liquid monomer that lies out of the. Then the mass is continuous in a second. Condenser 55 flows, is needed, the valve 63 is transferred to the mixing vessel, in which the viscosity is set to unopened, so that the liquid monomer that is in the ferry increases to 2500 poise (i.e. 55 to 65% conversion) 58 is collected, 40 can flow into line 9. This latter device is a vertical one and runs back to pot 1. Vertical screw conveyor attached by actuation, specifically of the valves 61, 62, 63, 64, 67 and 69 it is possible to ent- for the treatment of viscous solutions, which a good neither container 57 or 58 is intended for the collection of heat transfer. After this to use condensed volatiles. If one of the point, however, it becomes economically inexpedient to use Container for collecting the condensate is needed, 45 this device is a further conversion of the poly the valve between the other container and the merisats to carry out because of the lowered VorLeitung 9 opened, so that the liquid styrene again to directional size, which is caused by the heat conduction of the polymer the pot 1 can flow back. Usual sockets, connections, etc., are required within the system because of the reaction conditions and because of the higher turns. 50 power consumption. Accordingly, the polymerization will

As a result of the rapid passage of the polymerisation stopped at this stage, where the process was economical approximately and technically disadvantageous (i.e. at approximately 1 to 3 minutes, a device for the 70%, preferably 55 to 65% conversion is unnecessary). At this Exchange of working heat. That to the point of volatilization becomes the unchanged monomer quickly and Application zone of the extruder applied vacuum 55 completely from the partially polymerized material removes the volatile material caused by the increased 1 to 3 minutes by using a combined, Temperature and the activity of the extrusion device against each other rotating twin-screw extruder emerged is, and a product greater than 98% and and evaporator removed. The one in the previous one The extruder generally described as being 99% polymeric material has two vacuums obtained from the extruder. The return 60 (volatilization) zones; there can also be an or of the volatile fractions to the pretreatment pot, several such zones are used in which the. prevents material from being lost in the process. So unchanged monomers are removed and for the following the result is an efficient, economical process with reflux going back to the exit polymerization kettle Working without a special heat exchanger is obtained. The absolute pressure in this vacuum is possible is. 65 zones is 50 mm of mercury; a vacuum of about

The new method is particularly well suited for which 5 to about 200 mm can be used. The Be-polymerization of a monomer, which contains a considerable amount of material entering the proportion of impurities - often up to 50% - under approximately 13.6 kg pressure into the filling vessel of the atomizer, has a temperature that previously did not polymerize satisfactorily, of HO ⁰ C ; a temperature of about 80 to could become a polymer of good purity. 70 150 ° C can be used. The temperature of the

Claims (5)

1 UI * k <ώθ <* 9 10 Filling and the first vacuum zone of the combined temperature of 105 ° C polymerized (less than 0.75% Pressing and evaporation sections are heated to 170 ° C residual monomer). held (it should be at least about 150 _...._ up to 190 ° C) with a product temperature of un- Example 7 danger 150 ° C (150 to 185 ° C). In a very short time, i. H. 5 The method according to Example 1 with 650 parts of p-cyclo- in about 30 seconds but less than 5 minutes, hexyl styrene. The polymer product has a heat de- in the closed heating zone the combined temperature of 109 ° C and contains less than The compression and evaporation device ned the 0.6% residual monomer.
Temperature of the product instantly to approx 240 ° C increased (the temperature should be in the range of _xo example 8 185 to 250 ° C). In this second zone, the 650 parts of methyl styrene (65% p-isomer, 35% m-iso content of residual monomers in the product to less than meres and 2% o-isomer) and an a-methylstyxol-0.5% are reduced. The product is extruded through a strand mixture (weight ratio 4: 1) after an additional press with many openings and is implemented in game 1. A polymeric product that cut fewer 3.2 mm diameter tablets suitable for 15 than 0.7% residual monomer and heat distortion molding compound. The color and clarity has a temperature of 105 ° C, is obtained
of the polymer is very good and the heat distortion. In the process according to the invention, the part temperature should be introduced because of the very low residue on wise polymerized insert, which is introduced into the combined volatiles in the polymer very high, about 90 ° C and higher . ao will contain approximately 40 to 70% solids. In example 2 polymerization to this degree in the pretreatment or in the pretreatment pot and the cooling coil 650 parts of methylstyrene, containing 65% p-isomer, treatment is a polymerization time of about 33% o-isomer and 2% m-isomer, the purity of 8 hours is usually sufficient; it may be as high as 99.5%, will be _{extended to approximately 24 hours according to the procedure of 25} when treating Example 1 lower poly. The residue of monomers! can be used in merization temperatures. When that of the polymerized product is 0.3%. The poly- partially polymerized insert, which contains from 40 to about mere heat distortion temperature of 95 ° C. 70% solids, is removed from the cooling coil zone. . removed, the polymer has an increased viscosity eispiei ό _{3o UJ1 (} j - ^ ^ _{n emem} state, which controls the exo- 650 parts of methyl styrene, which makes the same isomeric co-operation difficult. At that point, that becomes composition like the monomer of Example 2 and a polymer in the combined expressing and evaporation purity of approximately 92%, are filled according to the inoculation device, in which the active constituents play 1 treated. The residue of the monomer in the part, i.e. H. the unchanged monomer, removed immediately Polymer is 0.4% and the heat deformation and further polymerization is prevented so that temperature 95 ° C. With this monomer, one only avoids a runaway of the exothermic reaction part of the volatilized material is returned to the reflux. As mentioned, the time in which the partial about the use of monomers! with the same polymerized use in the combined extrusion and Obtain a purity content of about 90%. Evaporation device is held, about 1 to _. 40 3 minutes. By regulating the speed, the example 4 revolutions of the screws, control of the screw 50 parts of methyl styrene with 50 parts of impurities, plant, the extrusion mold through which the material the predominantly, d. H. to about 49 parts, is pressed from ethyl etc., the optimal residence time of the toluene and other impurities are used in the combined extrusion and evaporation process polymerized to a near 100% conversion, 45 setting device. The use will taking a 50% polymer solution of polymethyl under vacuum and at elevated temperature in the komstyrene in ethyl toluene, etc. is obtained. This solution is combined with an extrusion and evaporation device then in the combined expressing and evaporation hold, with the unpolymerized monomers and device as in example 1 filled. A pure poly- the non-polymerizable compounds as a result of the vermeres The combined extrusion and reduced pressure and the increased temperature become an evaporation device obtain. The ethyl toluene that volatilizes and is removed. The to obtain a contains about 1% impurities is required for the styrene type polymerized product further use recovered. This greatly reduces the total duration. With a monomer of 50% purity it is possible to bring the polymer to 100% conversion because, 55 patent claims:
although it is fully polymerized, the polymer is not that extremely high viscosity of relatively pure mono- 1. Process for the production of thermoplastic meren achieved; there are only 50% polymer in polymer by polymerizing a monomer, the mixture. the general formula Example 5 ^6o Using equal proportions, 3-methoxystyrene is obtained polymerized according to Example 1. The polymer contains _{/ πη} ( ^ —C = CH ₂ 0.5% residual monomer and has a heat de- '" temperature of 114 ° C. 6g Example 6 in which R is hydrogen, chlorine or methyl radicals, R ' Hydrogen, chlorine, lower alkyl, lower alkoxy 650 parts of monomeric p-tert-butylstyrene are after or cyclohexyl radicals and η is an integer from 0 to Example 1 for a polymer of a heat deformation 70 2 means, characterized in that the Monomers allowed to react at a temperature of about 85 to about 120 ⁰ C until a polymerization mixture with a content of not more than about 70 ° / ₀ of polymeric material is obtained, the partially polymerized mixture containing unreacted monomeric material by a combined extrusion - and vaporization device, which is kept at a temperature of about 110 to about 225 ⁰ C and an absolute pressure of less than 200 mm of mercury, runs in a time of less than about 5 minutes, the polymeric material being pressed out and the unreacted at the same time monomeric material is evaporated therefrom, and that the volatilized unreacted monomeric material is separately withdrawn to a residue of polymer of more than 98 ° / ₀ and that the residue of polymeric material is pressed out of the zone. 2. The method according to claim 1, characterized in that the monomers are allowed to react in a pretreatment stage up to a conversion of approximately 45 ⁰ J ₀ of polymeric material, after which the further polymerization is carried out in a cooling coil stage until the material is up to a content of not more than 70 ° / ₀ of polymeric material is polymerized, and that this partially polymerized material, which contains unchanged monomeric material, through the combined extrusion and evaporation device, which is between about 160 and 210 ° C and at an absolute pressure of about 30 to 110 millimeters of mercury is maintained through in 1 to 3 minutes and the unchanged monomeric material recovered from the combined expressing and evaporating device is returned to the bulk of the polymerization mixture. 3. The method according to claim 1 or 2, characterized in that the polymerizable used Monomers a content of about 1 to 50 percent by weight of non-polymerizable material, based on the total weight of monomer and non-polymerizable material, and that both the unpolymerizable material and the unpolymerized monomer will eventually volatilize and withdrawn separately from the combined expressing and vaporizing device. 4. The method according to claim 3, characterized in that the polymerizable monomers used a non-polymerizable material content of about 30 to 50 percent by weight based on the total weight of monomer and attached material, the monomer is completely polymerized in the cooling coil zone. 5. The method according to claim 2, characterized in that the starting compound is a mixture of nuclear methylated styrene and α-methyl styrene is used, the weight ratio of nuclear methylated styrene to α-methylstyrene in the Size ranges from about 3: 2 up to about 9: 1. 1 sheet of drawings I 909 727/528 1.60