JPH0617409B2 - Anionic polymerization method - Google Patents

Description

Detailed Description of the Invention

The present invention relates to a novel method for controlling anionic polymerization reactions in continuous stirred tank reactors. The term "continuous stirred tank reactor" means that materials are added to and removed from the reactor continuously in approximately the same proportions, and the contents of the reactor are substantially uniform in both composition and temperature. Refers to any reactor maintained at. Thus, a continuous stirred tank reactor can have the form of a conventional stirred cylinder or a spherical tank, or it can be a loop where material is rapidly recirculated within the loop. Polymerization is often carried out using a Pragg flow reactor in which the composition at the inlet end is very different from the composition at the outlet end and the reaction gradient is present therein. This is not true for continuous stirred tank reactors. In a continuous stirred tank reactor in which monomer (optionally including diluent) and anionic initiator are continuously added and product is continuously removed for further processing and recovery of polymer (preferably as pellets). It is often desirable to make polymers using anionic initiators at. A particularly desirable property of commercial polymers is uniformity of both composition and molecular weight. Blending various batches to obtain apparent homogeneity is costly. The change in molecular weight between batches of polymer introduces many fabrication difficulties. Gels often form during polymerization, especially for alkenyl aromatic polymers. Such gels are readily recognized by the general lump nature of the strands when extruding the polymer into strands, and the formation of such lumps or slabs is roughly proportional to the gel content. Polymers containing such gels are generally not suitable for extrusion or injection molding. This is because the final product exhibits surface irregularities and deviates from the shape of the mold. U.S. Pat.Nos. 3,290,116, 3,468972 and 3,7
Attempts have been made to control anionic polymerization by a colorimeter as described in 43,629. In practice, the sensitivity of the colorimeter changes over time. Also, the impurities and diluents in the monomers, as well as the effective amount of initiator, will change over time. Therefore, it would be highly desirable if there were improved methods and apparatus for controlling anionic polymerization that would provide a substantially gel-free product of generally constant average molecular weight. These advantages include organic matter in a continuous stirred tank reactor in which the reactor contents are nearly uniform and the polymerization components are continuously added and the reaction mixture is continuously discharged from the reactor at substantially the same rate. In a method of anionically polymerizing an anionically polymerizable alkenyl aromatic monomer with a metal anion initiator; conversion of the monomer to polymer greater than 99% by weight and initiated corresponding to the molecular weight of the polymer in the discharge stream from the reactor It is achieved by an anionic polymerization process which is characterized by obtaining a substantially constant polymer molecular weight by controlling the rate of addition of the agent feed stream. A particularly preferred embodiment provides a first signal that varies with the molecular weight of the polymer in the effluent stream from the reactor, and this first signal changes the rate at which the polymerization initiator is added to the reactor to provide a substantially constant molecular weight. Holding the polymer, measuring the molecular weight of the polymer to obtain a second signal, and using this second signal
Compensating the first signal generator for signal generator deviations or errors, thereby maintaining a substantially uniform molecular weight of the polymer in the reactor effluent. Monomer supply device; monomer flow rate control device linked to the discharge part of this monomer supply device; anionic polymerization initiator supply device; initiator flow rate control device linked to the discharge part of this anion polymerization initiator supply device; inlet and outlet Has,
A continuous stirred tank reactor, the inlet of which is in communication with the monomer flow control device and the initiator flow control device during operation for receiving substances therefrom; connected to the discharge part of this continuous stirring reactor A discharge conduit in communication during operation; varying in response to changes in the molecular weight of the polymer in the effluent stream from the continuous stirred tank reactor, and adjusting the initiator flow control to provide molecular control of the polymer being produced. A device for generating one signal; a device for measuring the molecular weight of the polymer and generating a second signal representing the molecular weight of the polymer;
Anion comprising a device adapted to receive a second signal and adjust the device to provide the first signal, thereby providing a polymer of approximately uniform molecular weight; An apparatus for producing polymerized alkenyl aromatic polymers will also be provided in practicing the method of the present invention. The term "alkenyl aromatic monomer" has the formula (In the formula, R is hydrogen or methyl, and Ar is 1
At least 50% by weight of a monomer having an alkyl group containing 6 carbon atoms as a substituent or having 1 to 3 aromatic rings without such a substituent).
By means of anionic polymerizable monomers, the remainder of the monomeric material comprising monomeric materials capable of anionic copolymerization with alkenyl aromatic monomers. Representative alkenyl aromatic monomers that may be used alone or in combination include styrene, α-methylstyrene, vinyltoluene (all isomers; paravinyltoluene is preferred), ethylstyrene, propylstyrene, tertiary butylstyrene. , Octyl styrene, vinyl naphthalene, vinyl biphenyl,
Vinyl anthracene, and mixtures thereof. Anionic polymerization is well known in the art. Representative polymerization methods are U.S. Pat.Nos. 3,030,346, 3,954,894, 4,196,153, 4,200,713, and 4,205,01.
It is described in No. 6. It is generally desirable to carry out the polymerization in the presence of an inert solvent for the resulting polymer. As a typical solvent, benzene,
Toluene, ethylbenzene, and ethyltoluene may be used alone or in a mixture with a small amount of an alkyl compound such as cyclohexane. In the practice of the present invention, it is desirable to keep the temperature and composition of the reaction mixture uniform in the polymerization vessel. It is desirable to keep the temperature of the reaction mixture throughout the reaction mixture at a temperature difference of ± 3 ° C, preferably ± 1.5 ° C. In order to maintain the desired temperature and compositional uniformity in a recirculating coil reactor as described in US Pat. No. 3,035,033 (inventor, Schweiter), the volume of material circulating in the coil is added to the coil. And at least 15 of the capacity emitted from the coil
It should be twice, preferably 25 times. For stirred tank reactors, the temperature and composition of the reaction mixture should be uniform everywhere in the reactor except in the immediate vicinity of the monomer feed point. When a stirrer is installed directly in a 1.0 m 2 m high tank and the monomers are fed radially inward from the bottom of the tank, the temperature and composition of the reaction mixture are 0.1 m or more away from the feed point. It should be fairly constant in all parts of the vessel. In general, the greater the mixing, the greater the homogeneity of the product obtained and the less chance of gel formation. In the polymerizations carried out according to the invention, the conversion of monomer to polymer is usually above 99%, and due to the nature of the continuous stirred tank reactor and the rapidity of the polymerization, the solids level is almost constant. For every 1% solids variation of a reaction mixture of polystyrene of about 300,000 molecular weight, the molecular weight will change by about 4,000, giving the device for generating the first signal a great deal of latitude. The device that produces the first signal can be any of a variety of sensors that produce a signal representative of the molecular weight of the polymer. Generally, in anionic polymerization, the polymerization mixture provides colored anions. For example, in the polymerization of styrene using an organolithium initiator, a strong red coloration is induced, which is somewhat proportional to the number of end groups present and is therefore a measure of the molecular weight of the polymer. Viscometers are also useful, and analysis of the number of end groups is also useful. The second signal producing device is preferably a device which measures the molecular weight of the products in the reaction mixture and which substantially provides a reference against which the output of the first signal producing device can be compared. Various devices such as viscometers and light scattering devices are second
It can be used as a signal generator. However, the preferred embodiment is to use a gel permeation chromatograph which alternately measures the molecular weight of the polymer in the reaction mixture with a standard polymer of known molecular weight to give maximum confidence. FIG. 1 is a schematic diagram showing one embodiment of the present invention.
2 and 3 show diagrammatically the sampling method of the arrangement of FIG. FIG. 1 shows diagrammatically a device suitable for carrying out the method of the invention, which device is indicated generally by the numeral (10). The device (10) comprises a feed tank (11) with an inlet conduit (12), an inlet conduit (13) and an outlet conduit (14) in a cooperating combination. A pump (15) is arranged in the outlet conduit (14). The conduit (14) communicates with the water inlet conduit (17). Both conduits (14, 17) discharge their contents into a conduit containing a heat exchanger (19). The conduit (18) discharges the contents into the decomposition column (21). The discharge flow from the decomposition column (21) is led to a conduit (23) containing a heat exchanger (24), a decanter (25), a water discharge conduit (26) and an organic matter receiving tank (27). Organic matter from the receiving tank (27) is sent to the distillation column (29) via the conduit (28). The distillation column (29) has a discharge line (31, 32). Discharge conduit (31)
Incorporates a heat exchanger (33). The discharge conduit (31) connects to the conduit (32) and discharges the contents therein. The distillation column (29) has a discharge conduit (35) and a recirculation conduit (36) with a built-in heat exchanger (37). Conduit (35) discharges the contents to an overhead discharge conduit (38) as well as a second distillation column (38) with a bottoms circulation similar to column (29). The conduit (39) has an internally arranged condenser (42). The conduit (41) has an internally arranged tank (43, 44). The tanks (43,44) are connected in series. Conduit (41) terminates in a continuous stirred tank reactor (46). Reactor (46) is inlet (47)
And with an exit (48). Reactor (46) is in the form of a closed loop and contains a pump (46a) to provide agitation or circulation of liquid in reactor (46). The anionic polymerization initiator supply tank (51) is connected to the conduit (41) by the conduit (52). Conduit (52) is a flow controller or variable speed pump
(53) is built in. Outlet (48) of continuous stirred tank reactor (46)
Are in synergistic combination with the conduit (55). Arranged within the conduit (55) is a device (56) for providing a signal that varies depending on the molecular weight of the polymer contained in the material flowing through the line (55). A device for giving a first signal to the line (55), which changes as the molecular weight of the substance flowing through the line (55) changes.
(57) For example, a hue detector is arranged. Controller (5
8) is in working combination with device (56,57) and pump (53). A conduit (55) remote from the outlet (48) discharges the contents into a terminal stirred reactor (61). In addition, the inlet conduit (62) and the discharge conduit (63) with the pressure control valve (64) built-in are equipped with a terminal stirring reactor (6
It is connected to 1). The conduit (63) discharges the contents to the devolatilizer (65). The devolatilizer (65) has a bottom discharge conduit (6
6) and overhead discharge conduit (67). This conduit
In the (67), there is a quality display device (68) such as an infrared analyzer. FIG. 2 shows diagrammatically a sampling arrangement for measuring the molecular weight of the polymer discharged from the polymerization reactor (46a) to line (55a). As shown in FIG. 2, the conduit (71)
Selectively communicate with line (55a). The conduit (71) discharges the contents into the mixing chamber (72). The mixing chamber (72) is preferably of small capacity and has an agitator (73) inside. Advantageously, the stirrer (73) is magnetically actuated. Mixing chamber (7
2) is associated with this, and the nitrogen or other inert gas supply conduit (7
4) and vent conduit (75). Each of the conduits (74, 75) has a built-in valve. The mixing chamber (72) discharges the contents into a conduit (77) to the gel permeation chromatograph. The conduit (77) contains a valve. The standard polymer feeder has an associated valved conduit (79) which is connected to the gel permeation chromatograph (81). A line (77) from the mixing chamber (72) is also in communication with the gel permeation chromatograph. As shown in FIG. 2, a suitable solvent such as tetrahydrofuran is pumped into the gel permeation chromatograph at a pressure of 515 KPa (60 Psig). Material from the polymerization reactor (46a) passes through line (55a) and through the four-pronged valve (82). In FIG. 3, the four-pronged valve (82) is rearranged and the line (5
Part of the material flowing through 5a) passes through the conduit (71) to the mixing chamber (72)
And passed through a gel permeation chromatograph. Although the method of the present invention can be used to produce a wide variety of polymers, FIG. 1 shows a sequence particularly suitable for the production of polystyrene from ethylbenzene. Ethylbenzene is fed to conduit (12), stored in tank (11), through conduit (14) and pump (15) to conduit (1
8), where it is mixed with water to form a mixture of ethylbenzene and steam, which then enters the cracking column (21). The effluent from the cracking column passes through line (23) and heat exchanger (24), where the effluent is cooled. The effluent from the cracking column after cooling passes through the decantation tank (25) and water is discharged from the conduit (26). Crude styrene enters the crude styrene tank (27) from the decantation tank. Crude styrene spills from tank (27) through conduit (28) into the distillation column. The distillation column serves to remove low boiling impurities such as benzene, toluene and residual water. First
The bottoms fraction from the distillation column (29) passes through line (35),
Some are recycled and heated through line (36) and heat exchanger (37). The conduit (35) discharges a fraction mainly consisting of ethylbenzene and styrene to the distillation column (38).
The high-boiling fraction, which mainly consists of tar and cumene, is discharged from the bottom of the distillation column (38). The overhead fraction from the second distillation column enters the polymerization reactor (46) through conduit (41) and tanks (43,44). This overhead fraction is a roughly equal mixture of ethylbenzene and styrene. After mixing with the anionic polymerization initiator from conduit (52) and pump (53), the effluent from the continuous stirred tank reactor (46) is
5) and emitted through detectors (56,57). Conduit (55)
Discharges the contents into another continuous stirred tank reactor where the polymer is mixed with ethanol to deactivate it. The effluent from the reactor (61) is a conduit (63) and pressure control valve.
Through devolatilizer (65) is passed through (64) where ethylbenzene is removed and molten polystyrene is removed from devolatilizer (65) via conduit (66). The molecular weight detector (56) provides a signal to the computer (58) indicating the weight average molecular weight of the polymer. The color detector (57) also provides a signal to the computer (58), and the computer adjusts the set point of the color detector (57) to obtain a nearly constant molecular weight polymer. Computer (58) pump (53)
Signal to provide the desired amount of anionic initiator to maintain the desired weight average molecular weight. In practical use,
Normal continuous monitoring of molecular weight is not necessary. From a practical point of view, the molecular weight should be monitored at least every 8 hours and the set point of the color detector should be adjusted accordingly. Preferably, the measurement of molecular weight and the adjustment of the set point are performed every 2 hours. The molecular weight control system (56a) shown in FIGS. 2 and 3 allows for intermittent sampling of product streams and dilution of fixed volume streams. This dilution occurs in chamber (72). Material is gel permeation chromatograph
Follow (81). Criteria are used to ensure close control of product molecular weight and accuracy of results from gel permeation chromatographs. That is, a solution of a polymer having a known molecular weight and distribution is passed through a gel permeation chromatograph for calibration. Gel permeation chromatography is the preferred method of molecular weight measurement, but other techniques such as melt flow, solution viscosity, light scattering, and vapor phase osmometry can also be used. In the practice of the present invention, the residence time of the material in the reactor is 1
It is desirable to be ~ 3 hours. If the residence time is less than 1 hour, it will be difficult to control the molecular weight, and if the residence time exceeds 3 hours, the retentivity of the process will be reduced. Polymerization temperature is 80-1
It is highly desirable to keep between 40 ° C. If the temperature is lower than 80 ° C, the amount of the initiator used becomes excessive, and if the temperature exceeds 140 ° C, the conversion rate from the monomer to the polymer decreases.
The polymer to solvent percentage in the reactor is 30-80.
It should be in the weight% range. Solid content of reactor is 3
If it is less than 0% by weight, excess solvent must be evaporated for polymer recovery, and if the solid content of the reactor is more than 80% by weight, the viscosity of the reaction mixture is lower than that which can be operated by the most practical processing equipment. Will also be higher. The generally desired solvent is an alkyl aromatic material. Ethylbenzene is the most commercially used, but xylene and toluene can also be used. The main advantage of the process of the invention is that very low yellowness polymers can be prepared using low levels of lithium initiators. In order to achieve the desired results, the oxygen content of the feed stream to the reactor should be kept below 1 ppm by weight, based on the weight of the total feed stream. If it exceeds 1 ppm, the hue of the recovered polymer is adversely affected. Similarly, water (if present) should be present in an amount less than 10 ppm and active hydrogen organic compounds such as acetylenes, and oxygen-containing compounds should be kept at a concentration less than 60 ppm. This is because such substances also adversely affect the coloring of the polymer.
The recovered polymer should contain less than 20 ppm lithium. This is because the presence of lithium adversely affects the hue in the present polymer. Desirably, a monomer to polymer conversion of greater than 99% by weight is achieved. The present invention will be described more specifically by the following examples. Example 1 The apparatus shown in FIGS. 1 to 3 was used. The cracking column had three parts: preheating part (ceramic Bery.
A length of about 1 m filled with a saddle), a cracking part (a length of 0.5 m filled with an iron oxide-containing cracking catalyst commercially available under the trade name of Ciel 105, which has an hourly space of 2.14 round-trip times), And the third part (discussed below).
Cracking temperature is 625 ° C and pressure is 1
It was 36 KPa (5 psig). In the third part of the decomposition column, the temperature was reduced to 300 ° C. The first two decomposition column sections were each heated by a ceramic heater of about 2500 Watts. The water: ethylbenzene ratio was 0.9. A condenser equivalent to the condenser (24) was cooled with water. Condenser
There is a gas-liquid separator between (24) and the decanter (25),
This was a flat tank with a volume of 490 m ³ . This gas
Styrene from the liquid separator through a tank equivalent to tank (27)
Pumped into distillation column. The first distillation column has a diameter of 5.
The light fraction was removed from the crude mixture using a packing to give a theoretical plate number of 0 cm and greater than 40 plates. The primary substances removed were benzene, toluene and water. The bottoms cut from column (1) was fed to the second distillation column. The first distillation column was operated under a pressure of 17.3 KPa with a bottom temperature of 90 ° C. and a reflux ratio of about 5: 1. The second distillation column has a diameter of 10 cm and is filled with packing material.
It had zero theoretical plates. Second distillation column at 14.6KP
It was operated at a pressure of a and a bottom temperature of about 85 ° C. The reflux ratio was 6: 1. The overhead composition removed from the second distillation column was a mixture of styrene and ethylbenzene in a ratio of about 1: 1. The bottom was mainly tar and para-cumene. Both distillation columns had a band time of about 2 hours. About 2 tanks are equivalent to the tanks (43,44)
It had a residence time of 4 hours. 240KPa for both tanks
It was kept under a nitrogen atmosphere with a pressure of (20 psig). Impurities other than styrene and ethylbenzene were kept below 100 ppm (weight). Two necks of material from tank (44)
A 0.63 cm Milton-Roy piston pump pumped to a continuous stirred tank reactor (46). The reactor was a recirculation coil composed of 316 stainless steel tubes of 2.5 cm diameter connected in a square. This steel pipe was jacketed and heated with hot water. The content of the stainless steel tube reactor is anothern gear pump (stock
No. 4448) was used for internal circulation. The internal volume of the reactor was 1867 m ² . A gear pump was placed adjacent to and downstream of the ethylbenzene and initiator inlets to facilitate mixing of the initiator and the feed mixture and to promote circulation of the viscous polymeric material within the reactor. A pressure control valve maintained the reactor pressure at 450 KPa (50 psig), for example, by operating valve 64 in FIG. The polymerization initiator used was n-butyllithium purchased as a 15% solution in heptane and diluted with toluene before use to yield about 1/2
An n-butyllithium concentration of .about.1 wt. The pump used to deliver n-butyllithium was Milton-Roy driven by a computer controlled variable speed electric motor.
It was a piston pump. The computer programs used were as follows: In addition, the current computer programs are created and operated exclusively in English, and there is no one that is created and operated in Japanese. f0: ^* Z + 1 → Z f1: ^* sfgo; spc2; prt “Valves off ot”; cfg1; cf
g3; sfg8 f2: ^* sfg0; spc2; prt "Color control off at"; c
fg2 f3: ^* sfg0; spc2; prt "Mw control off at; cfg3 f4: ^* sfg0; cfg10; prt" PF Cntrl off at "f5; ^* → X; sfg5 f7: ^* → V [X]; sfg6 f11: ^* if V [3] ^* 12> = 360 and I> V [2
0] +130; V [3] ^* 12-2 → If13: ^* sfg0; spc2; prt “Valves on at”; sfg1; “s
tand by ”→ BS f14: ^* sfg0; spc2; prt“ Color contrcl on at ”; sf
g2 f15: ^* sfg0; spc2; prt "Nw control cn at"; sfg3 f16: ^* sfg0; sfg10; prt "PF Cntrl or at" 0: "Anionic Polymerization Control Program w / GP
C; Patent Case ”; 1:“ # 's 2-16, Initializes hardward & so
ftware ”; 2: dim BS [20], AS [14], D [150], T [15
0], V [35], M [7], W [7], F [7], CS [2
0], C [3] 3: “Initializes variables, loads sp. Function key
s ”; 4: -3I; 3} r; 2} Z; 1} R; sfg 7; trk 1; ldk 1; gsb
"Time" 5: "Calls for needed variables, clears723 bus"; 6: gsb "assign"; rds (723)} J; on err "error" 7: "fmt # 1 for relays, # 2 for A / D; # 3 for D /
A; # 4 for display ";8:" fmt 1; "0140TG", fz4.0, "T", z 9: fmt2, c, z; fmt3, c, f4.0, c, z; eir7 10: "Clears D / A card"; 11: wrt 723,2 "0120TD0000TD2000TD4000TD6000T" 12: "# 's 14-16 initialize clocks"; 13: "U1 for int / detect., U2 for int / valves, U3 co
unt / detect. 14: wrt 9, “A, U1 ＝, U1 ＝ 01, U2 ＝, U2 ＝ 02, U3 ＋ 13, Ur
= 14 ”15: wrt 9,“ U1P3000 / U2P5000 ”16: oni 9,“ clock ”; eir 9; wrt 9,“ U2G ”17:“ # 's 19-44, main display loop ”; 18:“ Display for sampling system ”; 19: if Z = 1 and flg1; dsp BS, D, V [3] −I / 12, K 20: if Z = 1 and not flg1; dsp“ Sampling system is
off, ”21: if not flg2 and flg3;“ Mw Ctrl ”} CS 22: if not flg2 and not flg3;“ Color Ctrl ”} CS 23: if flg2 and not flg3;“ Ctrl off ”} CS 24:“ Display for control mode & Parameters ”; 25: if Z = 2; dsp CS, H, V [5], r32 / 5.11 26: if Z = 3; dsp“ Term. trans. = ”, P 27:“ Display for GPC data ”; 28: if flg1 and Z = 4 and A / 2-int (A / 2) =
0; fxd 0; dsp “Last Mw =”, r21 29: if flg1 and Z = 4 and A / 2−int (A / 2) #
0; dps “Last MWD =”, r22 30: in not flg1 and Z = 4; dsp “GPC is off,” 31: “Display for MWD control”; 32: “Flg 5 set by SF Key, denotes operator variabl
e change ”; 33: if flg5; gsb“ variables ”34:“ Flg9 set by peak-end, enables GPC calc ”; 35: if flg9; gto“ GPC calc ”36:“ Flg0 set by SF Key, denotes var. change, gives
time ”; 37: if flg0; wrt9," R "; red9, AS; prt AS; c11'assig
n ';spc2; cfg0 38: "Shut down of valves"; 39: if r50 = 1; wrt9, "U1HU3HU3C"; wrt 723.1,0; 0}
K} D; -5} I 40: if r50 = 1; wrt 723.3, "0140TD", 2000,
“T”; wrt 723.3, “0140TD”, 6000, “T”; 0} r50 41: “End of loop”; 42: ifZ>6; 2} Z 43: fxd 2; gto 19 44: “GPCcalc”; cfg9 ； gsb “time” 45 ： prt “GPC Calculation” ； dsp “GPC Calc.in Progr
ess ”46:“ Finds peak start (S) by weighted avg. ”; 47: V [1]} r5 48: for J = V

[9] +15 to V

[9] -1 by-1 49: if J = V

[9] and 3 ^* V [1] <r5; prt "No p
eak-start found. "gto" peak error "50: if J = V

[9]; 1.1r5 r5; 15 + V

[9]} J; gto
48 51: ifD [J] + 2 ^* D [J-1] + D [J-2] <= D [J-
1] + 2 ^* D [J-2] + D [J-3] + r5; gto 53 52: next J 53: J-1} S; V [2]} r6 54: "Finds perk end (F) by weighted avg . ”; 55: for J = V [10] −15 toV [10] +1 56: if J = V [10] and3 ^* V [2] <r6; prt“ No per
k-end found. "Gto" peak errot "57: if J = V [10]; 1.1r6} r6; V [10] -15} J; gto
55 58: if D [J] + 2 ^* D [J + 1] + D [J = 2] <=
D [J + 1] + 2 ^* D [J + 2] + D [J + 3] + r6; gto 60 59: next J 60: J + 1} F 61: “Calc.slope (M) and intercept (B) of baseline” 62: (D [F] -D [S1) / (T [F1-T [S])} M 63: D [S] -M ^* T [S]} B 64: "Substracts baseline off of peak & checks for n
eg. values ”; 65: for J = S to F 66: D [J] -M ^* M [J] -B} W 67: if J <S + 5 and W <= 0 and J # S; J} S; g to 62 69: next J 70: For J = S to F; D [J] -M ^* T [J] -B} D
[J] 71: next J 72: “ckecks perk size & prints perk data”; 73: if max (D [ ^* ])>18; prt “peak too larg
e ”; gto“ peak error ”74: if max (D [ ^* ]) <2; prt“ Peak too smal ”
l ”; gto“ peak error ”75: prt“ Peak-height is ”, max (D [ ^* ]) 76: fxd 0; prt“ Peak-start is ”, S; prt“ Perk-end ”
is ”, F 77: gsb“ Sum ”78:“ If std. , bypass Mw calc. & control "; 79: if K = 0; 0} r9; gto 108 80:" Calc. 81: r4 ^* r7 / r5} r20; r4 ^* r6 / r73} r21; r4 ^* r11 / r6} r Mn, Mw, MwD ”;
12; r21 / r20} r22 82: wrt 723.3, “0140TD”, dto ((r21-V1301) / (V
[31] -V [30]) ^* 500) +2000, "T" 83: wrt 723.3, "0140TD", dto ((r12-V [32]) / V
[33] -V [32]) ^* 500) +6000, “T” 84: “If not Mw control, bypass”; 85: if not flg3; got 93 86: “Check of sample Mw dev. & First samp”; 87: If abs (r21-r35)> [16] and r35 # 0; prt “Mw de
v. "; Gto 93 88:" Calc.% Trans. change ”; 89: V [18] ^* (r21-V [4]) / 1000 / r33 90:“ Calc. new% trans. setpoint ”; 91: V [5] -r33 / V [5]; r21} r35 92:“ Round-off Mn, Mw data ”; 93: r20 ^* .001} r20; r21 ^* 001} r21 ; R12 ^* .001} r12 94: if r20-int (r20)> =. 5; r20 + 1} r20 95: if r21-int (r21)> =. 5; r21 + 1 r21 96: if r12-int (r12)> =. 5; r12 +} r12 97: int (r20) ^* 1000} r20; int (r21) ^* 1000} r21; int (r1
2) ^* 1000} r12 98: "Printer output of Mw data"; 99: fxd 0; prt "Mn =", r20; prt "Mw =", r21; prt
“Mz =”, r12 100: fxd 2; prt “Mw / Mn =”, r22; prt “Mx / Mw
=, R12 / r21 101: "If Mw control, prt new setpoint"; 102: if flg3; prt "New sp. =, V [5] 103: “If report mode on, prt”; 104: if flg 10; gsb “report” 105: “End of calc, return to dsp loop”; 106: 0} D} T; ≡ gto 19 107: “Check if old calib.holds”; 108: if abs (r5 ^* 6 / r7 ^ 2-V [11] <. 001; gto 118 109: “# 's119-127 calib.calc., successful” iterat
ion ”; 110: if r5 ^* r6 / r7 ^ 2-V [11]> = 0; gto 11 111: 1.05r8} r8; gsb“ Sum ”112: gto 110 113: if abs (r5 ^* r6 / r7 ^ 2-V [11] <. 0001; gto 118 114: if r5 ^* r6 / r7 ^ 2-V [11]) <0; r8} r9; r10} r
8; .5 (r8-49) + r9} r8; gto 116 115: r8} r10; .5 ^* (r8-r9) + r9} r8 116: gsb “Sum” 117: gto 113 118: V [12] ^* R7 / r6} r4; fxd 3; prt “Calib.consta
nts ”119:“ Printer output of calib. "; 120: fxd 0; prt" C1 = ", r4, fxd 3; prt" C2 = "", r
8; 0 D} T; gto 19 121: “Summing loop for Mw calc.”; 122: “Sum”; 0} r5} r6} r7} r11 123: for J = s to F 124: exp (r8 ^* T [J])} E 125: r5 + D [J] ^* E} / r5; r6 + D [J] / E} r6; r7 + D
[J]} r7; 11 + D [J] / E ^ 2} / r11 126: next J; ret 127: “Routine for reset of valves loop upon erro
r ”; 128:“ peak error ”; ifK # 0; gto 19 129: 0} K} D} T; -8} I; wrt 723.1,24; gto 19 130:“ Allows offline input of Mw data ”; 131 : "Offline"; 132: "Adjusts% trans. setpoint ”; 133: V [5] -V [18] ^* (V [19] -V [4]) / 1
0000} V [5] 134: prt “New (ol) sp =”, V [5]; ret 135: prt Valves is relay writing routine for GPC c
ycle time <30 min. ”; 136:“ I is 5 sec.counter, K is sample counter ”; 137:“ valves ”: I + 1} I; if I = V [3] ^* 12; 0} I 138 : If K = 0 and I = 0; wrt 723.1,40; “Inject st
d. "} BS 139: if K> 0 and I-4-V [28]; wrt 723.1,14;" Inj
ect sample ”} BS 140: if K = 0 and I = 4; wrt 723.1,200;“ Running s
td. “} BS 141: if K> 0 and I = 4; wrt 723.1,224 142: if K = V [15] and I = 5;“ Last sample ”} BS 143: if K> 0 and I = 5; wrt 723.1,20 144: if K <V [15] and I-V [3] ^* 12-118; wrt 72
3.1,1; “Sample coil”} BS 145: if K <V [15] and I = V [3] ^* 12-116; wrt 72
3.1,100; “Stirring”} BS 146: if I = V [17] +4; wrt 9, “U3GU1G”, 0} L 147: if I = V [20] +4; wrt 9, “U1HU3HU3C”; sfg 9 148: if K <V [15] and I = V [3] ^* 12-6; wrt 723.
1,0; “Stir stop”} BS 149: if K <V [15] and I−V [3] ^* 12-2; wrt 723.
1,4 150: if I = V [3] ^* 12-1; K + 1} K; if K = V [15] +
1; 0} K 151: ret 152: “Longvalves is for GPC cycle 30 min.”; 153: “Std / samp / wait / std / samp / wait .. orde
r ”; 154:“ longvalves ”; I + 1} I; if I = V [3] ^* 12;-
2} I 155: if I = -2; wrt 723.1,40; “ ^* Inject std.”} B
S; 0} K 156: if I = 3; wrt 723.1,200; “ ^* Running std.”}
BS 157: if I = 4; wrt 723.1,1; “ ^* Sample coil”} BS 158: if I = 5; wrt 723.1,0 159: if I = 6; wrt 723.1,1 160: if I = 7; wrt 723.1,100; “ ^* Running std.”}
BS 161: if I = V [17] +3; wrt 9, “U3GU1G”; 0} L 162: if I = V [20] +3; wrt 9, “U1HU3HU3C”; sfg 9 163: if I = 120 ; Wrt 723.1,0; " ^* Sample ready"} BS 164: if I = 122; wrt 723.1,4 165: if I = 127-V [28]; wrt 723.1,14; " ^* Inject
samp. ”} BS 166: if I = 127; wrt 723,1,224 167: if I = 128; wrt 723,1,20“ ^* Running samp. ”} B
S 168: if I = V [17] +127; wrt 9, “U3GU1G”, wrt 72
3.1,4000; 0} L 169: if I = V [20] +127; wrt 9, “U1HU3HU3C”; wrt
723.1,0; 1} K; sfg 9 170: if I = V [20] +128; “ ^* Waiting”} BS 171: ret 172: “Clock determines which clock (3 or 5 sec) in
terrupts and branches ”173:“ Accordingly, Also contains red for polycolo
r, termcolor, IR ”; 174:“ clock ”; wrt 9,“ T ”; rdb (9)} Q; eir 9 175: if bit (0, Q); c11′detector ′; gto 189 176: if not , flg1 or flg7; gto 179 177: if bit (1, Q) andV [3] ^* 12 <360; gab “valve
s ”178: if bit (1, Q) andV [3] ^* 12> = 360; gsb“ longv
alves ”179: A + 1} A; if A = V [27]; 0 A 180: if A # 0; gto 189 181: C [2]} C [3]; C [1]} C [2] ; C}
C [1] 182: wrt 723.2, "0160TA13T0260TAX"; ret 723, C; ot
dC / 40} C 183: “This avgs. polycolor over 4 readings for Rep
ort "; 184: (C + C [1] + C [2] + C [3] / 4} H 185: wrt 723.2," 0160TA12T0260TAX "; red 723, P; ot
dP / 40} P 186: “Clears IB bus & multiprogrammer”: 187: if not flg2; gsb “control” 188: “Clears IB bus & multiprogrammer”: 189: if rds (723) = 64; eir 7 190: iret 191: “Detector reads GPC detector, running clock, a
nd stores data ”; 192:“ detector ”; L + 1} L; eir 9 193: wrt 723.2,“ 0160TA11T0260TAX ”194: red 723, D; wrt 9,“ U3V ”; red 9, T; T / 60000}
T 195: otdD} D; D ^* .005} D; D} D [L]; T} T [L] 196: ret 197: “Supplies display for operator variable chan
ge ”; 198:“ variables ”; if flg5; gsb“ time ”; cfg5 199: if X = 1; dsp“ Peak-start sensitivity factor ”
? ”200: if X = 2; dsp“ Peak-end sensitivity factor? ”201: if X = 3; dsp“ GPC cycle time (min.)? ”202: if X = 4; dsp“ Mw setpoint? ”203 : If X = 5; dsp “% transmission setpoint?” 204: if X = 6; dsp “Controller gain?” 205: if X = 7; dsp “Reset constant?” 206: if X = 9; dsp “Minimum peak elution time? ”207: if X = 10; dsp“ Maximum peak elution time? ”208: if X = 12; dsp“ Molecular weight of standard
? ”209: if X = 12; dsp“ Moleculr weight of standard? ”210: if X = 13; dsp“ Min. cat.pump speed (%)? 211: if X = 14; dsp “Max.cat.pump speed (%)? "212: if X = 15; dsp"# of samples between std.? ”213: if X = 16; dsp“ Mw error deviation? "214: if X = 17; dsp" Clock-start counter? 215: if X = 18; dsp “% trans. adjust, constant? 216: if X = 19; dsp “Enter off-line Mw data! 217: if X = 20; dsp “Clock-stop counter? 218: if X = 21; dsp “New cat.pump speed (%)? ”219: if X = 27; dsp“ Read cycle (5 sec. Inc.)? "220: if X = 28; dsp" Injection time (4 sec. Inc.)? " 221: if X = 30; dsp “Mw Molytek zero? "222: if X = 31; dsp" Mw Molytek max.? 223: if X = 32; dsp “Mz Molytek zero? 224: if X = 33; dsp “Mz Molytek max.? 225: if X = 0; ret 226: if not flg6; jmp 0 227: c11'print '; ret 228: "Control of NBL pump from% trans.deviation
s ”: 229: control”; 230: HV [5]} r30; r30 ^* V [6] + r31} r32 231: if r32 <V [13] ^* 5.11; V [13] ^* 5.11} r32 232: if r42 > 5,11 ^* V [14]; V [14] ^* 5.11} r32 233: if flg4; gto “pumps” 234: r3i + r30 ^* V [7]} r31 235: if r31> V [14] ^* 5.11 V [14] ^* 5.11} r31 236: if r31 <V [13] ^* 5,11; V [13] ^* 5,11} r31 237: “pumps”; wrt 723.3, “0140TD”, dtor32,
“T” 238: ret 239: “Routine for printing time of variable chang
e ”: 240:“ time ”; wrt 9,“ R ”; red 9, AS, spc 2; prt
AS; ret 241: “Output of report data after GPC calc.”; 242: “report”; fxd 2 243: prt “pump speed =”, r32 / 5.11 244: prt “% trans. =,“ H; spc 2 ； ret 245: “Checks to see if all needed var.are assigne
d ”; 246:“ whenever control mode change is made. 247: “assign”; 248: if flg2; gto 255 249: if V [5] = 0; 5} X; gsb “variables” 250: if V [6] = 0; 6} X; gsb “variables 251: if V [7] = 0; 7} X; gsb “variables” 252: if V [13] = 0; 13} X; gsb “variables” 253: if V [14] = 0; 14} X Gsb “variables” 254: if V [27] = 0; 27} X; gsb “variables” 255: if not flg1; gto 272 256: if V [3] = 0; 3} X; gsb “variables” 257 : If V [1] = 0; 1} X; gsb “variables” 258: if V [2] = 0; 2} X; gsb “variables” 259: if V

[9] = 0; 9} X; gsb “variables” 260: if V [10] = 0: 10} X; gsb “variables” 261: if V [11] = 0; 11} X; gsb “variables” 262: if V [12] = 0; 12} X; gsb “variables” 263: if V [15] = 0; 15} X; gsb “variables” 264: if V [17] = 0; 17} X; gsb “variables” 265: if V [20] = 0; 20} X; gsb “variables” 266: if V [28] = 0; 28} X; gsb “variables” 267: if V [30] = 0; 30} X; gsb “variables” 268: if V [31] = 0; 31} X; gsb “variables” 269: if V [32] = 0; 32} X; gsb “variables” 270: if V [33 ] = 0; 33} X; gsb “variables” 271: cfg 7 272: if not flg3; gto 276 273: if V [4] = 0; 4} X; gsb “variables” 274: if V [16] = 0; 16SX; gsb “variables” 275: if V [18] −O; 18SX; gsb “variables” 276: ret 277: “Supplies printed copy of operator variable
change ”; 278:“ print ”; cfg 6 fxd 0 279: if X = 1; fxd 3; prt“ Upslope factor = ”, V
[1] 280: if X = 2; fxd 3; prt “Downslope fact. =”,
V [2] 281: if X = 3; prt “GPC cycle time =”, V [3] 282: if X = 3 and V [3] ^* 12J = 360; sfg 8; prf
“Override to longvalves”; Leep 283: if X = 4; prt “Mw set point =”, V [4] 284: if X = 5; fxd 2; prt “% transmittance setpoin
t = ”, V [5] 285: if X = 6; fxd 3; prt“ Controller gain = ”, V
[6] 286: if X = 7; fxd 3; prt “Reset constant =”, V
[7] 287: if X = 9; prt “Min.peak time =”, V

[9] 288: if X = 10; prt “Max. Peak time =”, V [10] 289: if X = 11; fxd 2; prt “MWD of std. =”, V [1
1] 290: if X = 12; prt “Mw of std. =”, V [12]; V
[12]} r1} r2 291: if X = 13; prt “Min.cat speed =”, V [13] 292: if X = 14; prt “Max. Cat speed =” V [14] 293: if X = 15; prt "Samp.cycle =", V [15] 294: if X = 16; prt "Mw dev.limit =", V [16] 295: if X = 17; prt "Clock start =", V [17] 296: if X = 18; fxd 3; prt “% trans.adjust.constant
= ”, V [18] 297: if X = 19; prt“ Off-line Mw = ”, V [19]; gsb“ offline ”298: if X = 20; prt“ Clock stop = ”, V [20] 299: if X = 21; fxd 2; prt “Pump speed =”, V [2
1]; V [21] ^* 5.11 r31 300: if X = 27; prt “read cycle =”, V [27] 301: if X = 28; prt “Inject time =”, V [28] 302: if X = 30; prt “Mw Molytek zero =”, V [30] 303: if X = 31; prt “Mw Molytek max. =”, V [31] 304: if X = 32; prt “Mz Molytek zero =”, V [32] 305: if X = 33; prt “mz Molytek max. =”, V [33] 306: 0} X; spc 2; ret 307: “error”, wrt 723.1, 4000; wait 15000; wrt 72
3.1,0; stp ^* 1106 In this program, statements 2-16 activate all variables and clear all cards. A true clock is set to use and started. Statements 19-43 control a 9825 model display that can be charged by the operator by pressing a special function key (SFK) fl on the computer. Statements 44-126 calculate the Mw (molecular weight) of the polymer from the detector reading. Do this segment when all readings are correct and under the control of the valve subroutine. Statements 88-91 actually modify the colorimeter-initiator addition rate control loop. Statements 98-100 print Mw information on paper tape. Statements 130-1
34 takes the Mw input off-line. That is, the operator can enter Mw information from another external source (eg, another GPC) to modify the colorimeter-initiator addition rate control loop. Statements 135-171 include the subroutines "valve" and "long valve".
"Valve" is GPC when GPC cycle is less than 30 minutes
Control the sampling valve. This control is accomplished by writing to the relay card and turning on and off certain relays. This is also relayed via ASCO ^*
Whitey by powering the selenoid valve
^* Open and close the ball valve. The length of the GPC cycle is defined as the number of times the Mw information is received, that is, the number of times a sample is made and passed to the GPC. The frequency of normalization (how many samples followed the standard) can be varied by the variable V [15]. Also, CP
The C cycle (V [3]) can be changed in increments of 5 seconds.
The other variable factor included in this subroutine is the injection time V
Control [28], and computer "searches" for injected samples [V17] and [V20] in GPC detector.
Control the time of day. A "long valve" has all of the above characteristics but with some minor variations: (1) it uses for GPC cycle times of 30 minutes or more,
And (2) it only allows standard sample cycles; s
ample std, sampie ... Statement 172-190; The "clock" of the subroutine does two important things. First
In fact, it determines what of the signals the true-time clock is issuing at the time of interruption must be read from the output device. Second, it reads the input signal from either a colorimeter or a GPC detector. The "detector" of the subroutine is used to read the GPC detector. Statements 228-238 are the colorimeter control subroutines,
It is based on the anion concentration in the reactor effluent and is used to calculate the continuously changing initiator addition demand. It then emits a new voltage on the D / A card to change the rate of addition. This is done by varying the amount of power supplied to the motor driving the initiator addition pump.
The computer provides a 0-10V signal to the PARAJUST ^* motor controller, which then changes the power output to the motor. The SpecialFunctional Key Tape is a printed copy of the statement, stored in a special functional key on your computer. These statements allow the operator to control aspects such as controls, variable values, displays, etc. These statements are stored on cassette tape and loaded into computer memory at statement # 4 (Trk1, 1dk1). It should be noted that not all computer program statements are used. Example 2 A 1: 1 weight ratio mixture of styrene and ethylbenzene was added to 55
The feed stream was purified by pumping into a heat exchanger at 0 ° C. and removing oxygen and most of the water present via a spray nozzle into a receiver with an internal pressure of 2.6 KPa.
From this receiver the feed was passed through a bed of molecular sieves (commercially available under the tradename Linde 3A). The bed length / diameter ratio was 18, and the feed rate through the bed was 5 parts by weight feed stream per part by weight molecular sieve. The resulting feed contained styrene and ethylene in a ratio of about 1: 1 and contained less than 1 ppm oxygen, 3 ppm water, 5 ppm or less benzaldehyde, 5 ppm styrene oxide, 5 ppm acetophenone, and about 40 ppm phenylacetylene. Purified styrene-ethylbenzene feed stream was double-cylinder 0.6c
The polymerization reactor was pumped using an m Milton-Roy pump. The polymerization reactors were two nearly cylindrical reactors commercially available under the trade name Parr and equipped with a hollow spiral pyramidal stirrer. This stirrer contained a cylinder that was slightly shorter in length than the interior of the spiral cone and slightly smaller in diameter. The lands were arranged spirally on the outside of this cylinder so that the hollow cylinder and the cylinder generated by the rotation of the lands were slightly smaller than the internal volume of the reactor. Such a reactor is described in US Pat. No. 4,239,863. The reactor was heated to 95 ° C using pressurized hot water.
The purified feed stream and initiator were introduced into the side of the reactor at a rate to give a residence time of 2 hours. About 6 initiators
It was n-butyllithium pumped at a rate to give 0 ppm. The pressure in the reactor was maintained at 450 KPa (50 psig) using a pressure control valve at the outlet. The flow from the reactor was fed to a terminal coil with an internal volume of about 467 cm ³ connected in a square with 316 steel tubes with an inner diameter of 2.5 cm. The material was circulated in the termination coil using a Northern Gear Pump Stock No. 4448 operating at about 200 revolutions per minute. A solution of 1 wt% ethanol in ethylbenzene was fed to the termination coil at a rate of about twice that of n-butyllithium fed to the polymerization tank. The effluent from the termination coil was then fed to a steam condenser equipped with a flat plate heater and screw extruder as described in US Pat. No. 3,014,702. The outer surface of the heater was maintained at a pressure of 4.67 KPa and the reaction mixture was heated to a temperature of about 240 ° C. to obtain a polymer containing 0.8 wt% volatiles. The molecular weight of the resulting polymer was maintained at 210,000 ± 5,000 over 24 hours.
The color tone of the product was excellent and the yellow index was 0.007. Example 3 A styrene-ethylbenzene mixture with a weight of about 1: 1 was purified as in Example 1, but on a larger scale, by analysis 42% by weight styrene, 58% by weight ethylbenzene, less than 1 ppm oxygen, A purified feed stream was obtained having a composition of 5 ppm water, 14 ppm acetophenone, 5 ppm benzaldehyde, 5 ppm styrene oxide, and about 34 ppm phenylacetylene. A polymerization vessel was used consisting of 1893 vessels with the condensation mounted vertically above the vessel. Condenser
It had a cooling surface of 14.7 m ² . The polymerization vessel and condenser were supported on a weighing cell, the output of which was used to control the volume of the reaction mixture in the polymerization vessel. The inside of the tank was depressurized using a vacuum system. Steam removal was used to maintain the desired polymerization temperature. A variable speed pump was attached to the bottom of the polymerization tank to remove the polymer solution. The speed of this pump was changed to maintain a substantially constant polymerization tank weight. A hydraulically driven stirrer rotating at about 100 revolutions per minute was attached to the polymerization tank. The condensate from the condenser was recycled to the feed stream. The polymerization tank was operated under the following conditions: Reactor inventory 630 Kg; Feed rate 3
86 kg / hour; residence time Reaction mixture temperature 100 ° C .; reactor pressure 31.5 KPa; n
-Butyl lithium 80 ppm (based on total weight of feed). This polymerization contains 21 ppm of lithium and the yellow index is
A product was obtained which was 0.029. The weight average molecular weight measured by gel permeation chromatography was 195,000 over 24 hours.
It was ± 10,000. The reaction was stopped by passing a section of 3.8 cm pipe with a fiber optic probe and a sidestream outlet (connected to a gel permeation chromatograph). The reaction mixture was then passed through a section of 15.2 cm shackled pipe containing 18 15 cm x 20 cm electrostatic mixing elements (commercially available from Koch Engineering Company). The shacket was heated to a temperature of 120 ° C. and a 5 wt% methanol solution in ethylbenzene was added to the reaction mixture prior to entering the electrostatic mixer at four opposing points approximately 90 ° from adjacent points of the pipe. , Pumped in at a flow rate of about 2.3 kg per hour. After the polymerization was completed, the partial polymer was devolatilized using two devolatilizers in series. The first devolatilizer operates at 160 ° C and 79.7KPa,
The second devolatilizer was operated at 240 ° C. and 2.65 KPa. Example 4 The method of Example 2 was repeated except for the following points. The feed mixture to the reactor was 42 parts by weight of paramethylstyrene, 2 parts by weight of paraethyltoluene, and 56 parts of ethylbenzene.
It was part by weight. Supply rate Was 1 reactor volume. The polymerization temperature was 80 ° C.
The weight average molecular weight of the obtained product is over 24 hours.
It was 340,000 ± 30,000. The resulting polymer was extruded through a strand die. The resulting strands had no visible lumps or gels. The product was suitable for extrusion and injection molding of high quality articles. Comparative Example 1 The method of Example 2 was repeated except that the stirrer was not rotated. The best molecular weight control obtained over 24 hours was about ± 100,000. The product was extruded to give yellow strands containing large lumps or gels. Moldings from such strands had a poor hue and poor appearance. Comparative Example 2 The colorimeter and gel permeation chromatograph described in Example 1 were equipped in a jacketed tubular reactor having a diameter of 1.2 cm and a length of 76 cm. At the inlet end of the reactor, a mixture of styrene and ethylbenzene (1: 4 by weight) was fed with a polymerization amount of n-butyllithium at a rate sufficient to give a residence time of 15 minutes. Atmospheric pressure steam was supplied to the jacket. A temperature sensor probe placed in the reaction mixture of the reactor showed a temperature range of about 20 ° C. This temperature and gel permeation chromatographic signal were used to control the reaction, yielding a product that varied ± 100,000 from average over 24 hours. The effluent from the reactor contained a large visible gel. The product was not useful as a good quality material for extrusion or injection molding. Comparative Example 3 A vertical stirring tube reactor having an inner diameter of 16.5 cm, an internal effective length of 1.40 m and a volume of 0.026 m ³ was used. The reactor was jacketed in approximately three equal zones, each zone equipped with a thermometer protruding into the reaction mixture. The top driven stirrer had a 2.5 cm diameter shaft and a 1.3 cm straight arm with 6.3 cm spacing on this shaft. A plurality of fixed rods with a diameter of 1.2 cm are placed in the reactor in the radial direction.
It was protruding by 6.17 cm. The fixed rod engaged with the arm of the stirrer in a finger-like manner during rotation of the stirrer. The reactor had a total heat transfer area of 1.04 m ² . The physical arrangement of the reactor was such that the axis of rotation was vertical. The reaction mixture had good mixing in the plane perpendicular to the axis of the reactor and stirrer shaft, but very poor or no mixing at the top and bottom. As a result, it was considered as a plug flow reactor. An external line connected the pump between the top and bottom of the reactor. The pump was able to recycle the contents of the reactor at a rate of 7.5 times per hour. Equal parts by weight of styrene and ethylbenzene purified as in Example 2 and a polymerization initiating amount of n-butyllithium solution were pumped into the top of the reactor. The reaction reagents were fed to the reactor at a rate of 1/2 reactor volume per hour for a residence time of 2 hours. The following temperature relationships were observed. In the operation for 24 hours, the weight average molecular weight could not be kept closer than ± 50,000. Most of the polymerization appears to have occurred in the middle of the reactor. Gels or lumps were observed when the product was extruded as strands and the polymer was unsatisfactory for extrusion or injection molding.

[Brief description of drawings]

FIG. 1 shows diagrammatically a device suitable for carrying out the method of the invention. 2 and 3 diagrammatically show the sampling method in the device of FIG. In the figure; 10 ... Device; 11 ... Supply tank; 12, 13 ... Inlet conduit; 14 ... Outlet conduit; 15 ... Pump; 17 ... Water inlet conduit; 19 ... Heat exchanger; 21 ... Decomposition column; 25 ... Decanter 27 ... Organic substance receiving tank; 29, 38 ... Distillation column; 31, 32 ... Release line; 33 ... Heat exchanger; 43, 44 ... Tank; 46 ... Continuous stirring tank polymerization reactor; 46a ... Pump; 47, 48 ... Reaction Inlet and outlet of the vessel; 51 ... Initiator supply tank; 53 ... Variable speed pump; 56 ... Polymer molecular weight corresponding signal generator; 57 ... Hue detector; 58 ... Control device; 61 ... End stirring reactor; 64 ... Pressure control Valves; 65 ... Devolatilizers; 68 ... Quality indicators; 72 ... Mixing chambers; 73 ... Stirrers; 81 ... Gel permeation chromatographs;

Claims (3)

[Claims] 1. An organic material in a continuous stirred tank reactor in which the reactor contents are substantially uniform and the polymerization components are continuously added and the reaction mixture is continuously discharged from the reactor at substantially the same rate. In a method of anionically polymerizing an anionically polymerizable alkenyl aromatic monomer with a metal anion initiator; conversion of the monomer to polymer greater than 99% by weight and initiated corresponding to the molecular weight of the polymer in the discharge stream from the reactor An anionic polymerization method characterized in that a substantially constant polymer molecular weight is obtained by controlling the addition rate of the agent feed stream. 2. The method according to claim 1, wherein the polymerizable alkenyl aromatic monomer is styrene. 3. The method according to claim 1, wherein the organometallic polymerization initiator compound is butyllithium.