GB1591726A - Continuous telomerization process and apparatus and liquid telomers produced thereby - Google Patents

Description

(54) CONTINUOUS TELOMERIZATION PROCESS AND APPARATUS AND LIQUID TELOMERS PRODUCED THEREBY (71) We, LITHIUM CORPORATION OF AMERICA, a corporation organised and existing under the laws of the State of Delaware of 449 North Cox Road, Castonia, North Carolina 28052, United States of America, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to a novel continuous process, and apparatus for simply and effectively carrying out such process, for the preparation of normally liquid, that is liquid at room temperatures of the order of 20 to 250C (or somewhat lower or somewhat higher temperatures), resinous telomers, in which the essential reactants utilized are (1) a normally liquid telogen, (2) a normally liquid organic solvent (which may be the telogen itself in which case no separate organic solvent is utilized, or, if not the telogen itself, then a non-reactive, generally liquid hydrocarbon, organic solvent in which the telogen is soluble), (3) an organometal telomerization initiator or catalyst which is soluble in the telogen or telogen solution, and (4) a taxogen in gaseous form. These reactants are reacted in a manner and under such conditions as to provide a novel continuous process for the production of the desired normally liquid telomers, resulting in novel telomers having a number of distinct improvements and advantages in relation to the properties of the normally liquid telomers, and in relation to processes of preparation of said telomers and apparatus for such production when compared with practices and knowledge heretofore existent in the art.

Normally liquid resinous telomers (sometimes the term "telomers" is generically characterized in the prior art as "polymers") produced by reactions of liquid telogens with gaseous polymerizable monomeric taxogens in the presence of organometal telomerization initiators or catalysts have been known to the art, as is shown by such illustrative U.S. Patents as Nos. 3,356,754; 3,678,121; 3,691,241; 3,751,501 and 3,760,025 and procedures utilized for the production of the normally liquid telomers thereof are fully shown and described therein.

Our present invention is generic insofar as it concerns the utilization of the aforesaid essential ingredients in reactions for the production of normally liquid telomers, the bases of the invention residing, among other things, in the manner of and means for carrying out the reaction or reactions for producing said normally liquid telomers employing the procedures and apparatus described below and utilizing the novel principles reflected thereby, and it also resides in improvements in the normally liquid telomers which are produced by the carrying out of said procedures. In its narrower and preferred embodiments, the invention is concerned more particularly with improvements over the inventions disclosed in the aforesaid U.S. Patents Nos. 3,678,121 and 3,751,501.

In general, said U.S. Patents Nos. 3,678,121 and 3,751,501 disclose, among other telomers, the production of certain novel telomeric normally liquid polybutadiene oils and processes for preparing them, said telomeric oils being characterized by containing, in the molecules thereof, one benzene ring per polymer chain, and which represent products which can be made to possess widely different physical and chemical properties which are achieved by carrying out the processes for their production under certain particular controlled conditions. In general, the procedures of said two patents involve, illustratively, the gradual addition of a monomer, such as 1,3-butadiene, in gaseous form, to a liquid telogen, such as toluene, or to an organic solvent solution of such liquid telogen, in the presence of an organolithium initiator or catalyst combination exemplified by the following: (a) An organolithium, such as n-butyllithium or dilithioisoprene, combined or complexed with an aliphatic tertiary diamine, such as N,N,N',N'tetramethylethylenediamnine, or (b) An organolithium, such as n-butyllithium, combined or complexed with another organoalkali metal, such as n-butylsodium or n-butylpotassium, optionally combined or complexed with an aliphatic tertiary diamine, such as N,N,N',N'tetramethylethylenediamine.

The reaction, as disclosed in said patents, may be carried out at various temperatures, but, most preferably, in the range of 25"C to 900 C, depending on the desired viscosity and molecular weight of the final telomeric product. Generally, the reaction is carried out in a batchwise manner, the 1,3-butadiene in gaseous form being gradually added to the mixture of toluene, organic solvent and organolithium initiator, no attempt being made to separate the processes of chain transfer and polymerization, said processes proceeding simultaneously throughout the 1,3-butadiene addition. The said 1,3-butadiene addition must be carried out gradually to prevent explosive or uncontrolled polymerizations from occurring and also to permit the formation of a more or less uniform product, (molecular weight distribution in the range of 24) of low molecular weight, generally in the range of about 500 to 5000 and in a relatively high yield, based on the amount of initiator or catalyst complex employed, generally of the order of 50150 pounds per gram equivalent of carbon-metal bond.

Continuous processes for the production of polymers have heretofore been proposed among which, by way of illustration, is that shown in U.S. Patent No.

3,297,793 for producing block copolymers of dienes and vinyl aromatic compounds where (a) a stream of a conjugated diene, such as 1 ,3-butadiene, (b) a stream of an organolithium initiator, such as n-butyllithium, and (c) at least one diluent stream, such as n-pentane, are continuously introduced into a prereaction zone in a prereactor wherein polymerization-is initiated, then passing the resulting prereacted mixture into a reaction zone in a reactor and introducing into said mixture a stream of vinyl-substituted aromatic compound, such as styrene, and recovering from the effluent from the latter zone a solid, rubbery block polymer of the said conjugated diene and said vinyl-substituted aromatic compound. The continuous process of this invention for the production of normally liquid telomers is radically distinguished from the process of Patent No. 3,297,793 in a number of respects including the fact that this process is concerned with the production of normally liquid telomers, and no prereaction mechanism such as that disclosed in said patent is involved because, in the present process, initiation takes place instantaneously, or essentially so, on contact of the reactants.

In U.S. Patent No. 3,780,139, a continuous polymerization process is disclosed for the production of solvent-free segment copolymers of conjugated 1,3-dienes and aromatic vinyl compounds and wherein, for instance, a mixture of 1,3butadiene, styrene, and an organolithium initiator is first prepared and gradually and continuously fed into a certain type of screw extruder while continuously removing said segment copolymers from the extruder at a rate commensurate with the rate of the feed. Again, this approach not only differs very substantially from that involved in the present invention but is, indeed, inconsistent with the concepts and principles involved in the invention. Wholly apart from the fact that Patent No.

3,780,139 does not involve the preparation of normally liquid telomers, a special premixing step and apparatus therefor are used in the practice of the patented invention. In the present process, wherein normally liquid telomers are produced, gaseous monomer is fed directly into the initiator-liquid telomer stream to effect instantaneous, or essentially instantaneous, reaction to produce telomer, which is, of course, not the situation in the case of Patent No. 3,780,139, over and above the further fact that the present process and apparatus are not disclosed in or suggested by said patent, and the normally liquid telomers obtained in the practice of the invention would be wholly unobtainable by attempting to follow the procedure or to use the apparatus of said patent.

Accordingly, one aspect of the present invention provides a continuous process for producing normally liquid telomers; wherein a solution is formed comprising an organometal initiator and a liquid telogen (as hereinafter defined) whereby the liquid telogen is metalated, and the solution is continuously passed through a plurality of reaction zones in each of which the solution is reacted with at least one gaseous taxogen which is selected from conjugated dienes and vinylsubstituted aromatic compounds, and wherein the gaseous taxogen is introduced into each reaction zone continuously as a controllled stream through fine apertures in a tubular member spaced from a wall and thereby defining a passageway so as to come into direct contact with the initial solution, in the case of the first reaction zone, or the resulting mixture which has left the previous reaction zone in the case of the second and any subsequent reaction zone, liquid telomer being recovered from the final reaction zone.

Another aspect of the present invention provides a normally liquid telomer prepared by the continuous process just indicated and having a viscosity substantially lower than the viscosity, measured in poises at 250C, of a liquid telomer made by a batch process utilizing the same ingredients in the same proportions and under the same temperature conditions.

A further aspect of the present invention provides apparatus for producing normally liquid telomers by the process just indicated comprising means for continuously passing a controlled stream of a solution comprising a liquid telogen metalated by an organometal initiator through a plurality of reaction zones each defined by a tubular member and a wall spaced from the tubular member, each tubular member having fine apertures extending therethrough, means for continuously passing a controlled steam of a gaseous taxogen through said fine apertures into each reaction zone and initially into direct contact with liquid therein, means connecting each reaction zone with a subsequent reaction zone to permit liquid to flow from one reaction zone to the next, and means for recovering liquid telomer from the final reaction zone.

In the practice of the present continuous process, the chain transfer (or transmetalation) and the polymerization phases involved in the production of the normally liquid telomers are isolated to a large extent. In order words, the metalation of the telogen is first effected by means of the organometal initiator, particularly an organolithium, and then the resulting metalated telogen is reacted with the taxogen in gaseous form to bring about chain transfer and polymerization of the conjugated diene and/or vinyl-substituted aromatic compound. This advantageously permits effective control of each phase of the process to enable production of the normally liquid telomers with a narrower molecular weight distribution than is obtainable in telomers using the same reactants in the same proportions but employing the batch type procedures described above in the aforementioned U.S. Patents Nos. 3,678,121 and 3,751,501. Thus, by way of illustration, utilization of the process of the present invention permits, in certain instances, the production of normally liquid telomers having a molecular weight of, say, substantially 4,000, as against the production of normally liquid telomers having a molecular weight of, say, 20 or 30 or 40 /" lower according to the batch type processes of U.S. Patents Nos. 3,678,121 and 3,751,501, but wherein the viscosity of the higher molecular weight normally liquid telomer made according to the invention is about the same or only little greater than that of the otherwise corresponding lower molecular weight normally liquid telomer made according to said U.S. Patent Nos. 3,678,121 and 3,751,501. In the same vein, liquid telomers made by the present continuous process and having a given molecular weight, say 4000, when compared with a generally corresponding batch-prepared liquid telomer having the same or essentially the same molecular weight, show a very substantially lesser viscosity than the batch-prepared liquid telomer, commonly of the order of 1/3 to 1/10'that of the batch-prepared liquid polymer.

The practice of the present invention has other advantages over prior known batch type procedures, such as are disclosed in U.S. Patents Nos. 3,678,121 and 3,751,501, in that it commonly results in producing very substantially greater yields of desired normally liquid telomers per unit time of operation than the yields obtained in such prior batch type processes.

The present invention and the principles involved therein can perhaps best be understood in connection with a consideration of the accompanying drawing which shows, schematically, a simplified arrangement of apparatus in which the process can readily and conveniently be carried out. As shown, it utilizes three unit reactors or contacting units connected in series, as will be described below, but it will be understood that, instead of three reactors, two, four, five or more reactors connected in series can be used although, in general, as a practical matter, a three or four reactor set up will be adequate and satisfactory in most cases.

In the accompanying drawing which will be discussed below and in connection with the continuous process, it will, of course, be understood, as has been stated above, that it is schematic or diagrammatic in nature, such items as various valves, pressure gauges, and other construction elements and the like have been omitted in the interest of simplicity and because those skilled in the art can readily construct the apparatus in light of what is actually shown and described. The embodiment shown in the drawing resides in the reactor or contacting unit combination and arrangements and the continuous process is described in connection with such embodiment. While, hereafter, the drawing will be described in connection with the utilization therein of particular reactant ingredients, other reactant ingredients of the nature disclosed herein can be employed to effect the production of other normally liquid telomers.

Referring, now, to the drawing, it shows a tank 10 (which is desirably provided with a preheater, not shown) in which is disposed a solution of the telogen, for instance, liquid toluene, as such or dissolved in a liquid hydrocarbon, for instance, n-hexane, and the organometal initiator or catalyst, for instance, a complex of nbutyllithium and potassium t-butoxide, with or without supplemental ingredients as, for instance, tetramethylethylenediamine (TMEDA). At least a substantial part, if not most or almost all, of the initial metalation of the liquid telogen may take place in said tank 10. A metering pump 11 pumps the telogen solution at a controlled rate through an inlet pipe 12 into the first reactor or contacting unit 13.

The reactor 13 is conveniently made up of a cylindrical tube 14 within which is disposed, centrally or concentrically within tube 14, another or inner cylindrical tube 16 thereby to provide an annular space 17 between the inner wall of cylindrical tube 14 and the outer wall of cylindrical tube 16 through which annular space 17 the liquid telogen solution flows upwardly. The tubes 14 and 17 may conveniently be made of stainless steel or glass or any other material which is corrosion resistant and inert to the ingredients with which they are in contact. The cylinder 16 is provided, preferably adjacent the bottom thereof, with a perforated section 18 having very fine apertures therein through which the gaseous taxogen may diffuse or pass, essentially as a stream, as hereafter described, to commingle thoroughly with the liquid telogen solution flowing upwardly in the annular space 17. The perforated section 18 may, and preferably does, extend around the entire circumference of the tube 16 and extends upwardly some distance from its lowermost or generally lower end, which distance is variable but, generally, is quite short, preferably 1/10 to 1/12 the height of the tube 16.

The perforations or apertures or openings in the perforated section 18 may vary somewhat in size or diameter but it is particularly preferred that they have a diameter in the range of 2 to 40 microns although the micron diameters can be greater, the objective being to enable the gaseous taxogen to diffuse through the perforations in the form of, in effect, a highly diffused stream-like gas for intimate contact with the upwardly flowing stream of liquid telogen. An alternative manner of providing a cylindrical tube 16 with fine apertures or openings at the lower end section is to utilize a commerical micro-screen porous cylindrical element, such as is used in industrial filters, and blank off or wrap around or block off the upper part thereof in any suitable manner to render said upper part impervious to the passage of the gaseous taxogen therethrough, leaving the lower part, to a suitable height or length, to provide the finely perforated or apertured section 18 through which the gaseous taxogen passes into the upwardly flowing body of telogen solution in the annular space 17. The cylindrical tubes 14 and 16 are supported at their lower ends on a base member 19 in fluid-tight relation by welding, sealing or other suitable or convenient means.

The gaseous taxogen, for instance, 1,3-butadiene, is admitted under pressure through a manifold 21 and passes through check valve 22 in conduit 23 and through flow meter 24 through a pipe 26 into the upper part of tube 16, then downwardly in the tube 16 from which it then issues or diffuses through the finely apertured section 18 directly into the upwardly flowing liquid telogen body or stream and is absorbed into the telogen stream and proceeds to react with the liquid telogen. The liquid telogen body or stream intimately intermingled with the gaseous taxogen continuously moving upwardly to the top of reactor 13 passes through outlet pipe 27, into contact with a thermometer 28 and thence continuous to move through the downwardly extending outlet conduit 29 and then upwardly into the next or second reactor or contacting unit 31 which is constructed similarly to the construction of the first reactor unit 13. The arrangement and sizing of the equipment are such that when the liquid telogen and gaseous taxogen reaction mixture have reached the top of the reactor 13 and move past the thermometer 28, and probably somewhat before, reaction of the 1,3-butadiene has occurred totally, or essentially totally, in regard to chain elongation. The arrangement and length of the conduit 29 are such that in the course of passage through the conduit 29, and probably somewhat before, total, or essentially total, transmetalation of polymer to liquid telomer occurs. The metalated or lithiated telogen is reformed and in the second reactor 31 the process of chain elongation is repeated. The processes of transmetalation and polymerization (or chain elongation) are repeated, respectively, in conduit 32 leading from reactor 31 and in the third reactor 33. In summary, transmetalation occurs essentially in the elongated downwardly extending conduits 29 and 32, or somewhat prior thereto, and chain elongation occurs in the annular chamber 17, or somewhat prior thereto, and in the corresponding annular chambers 34 and 36 of the reactors 31 and 33, respectively, in a manner similar and in a similar relation as to this solution with respect to chamber 17. Since the constructions of three reactors, the piping, the thermometer arrangement, and the gaseous taxogen feed and control system are the same in all three of the reactors, specific reference thereto and identification by numbering is superfluous and has, therefore, largely been avoided.

Some additional observations, however, appear to be in order so that an even more complete understanding of the continuous process and the invention may be had. The admittance of the gaseous taxogen is maintained constant, or essentially so, in all of the reactor units. In order to maintain a constant organometal initiator or catalyst to monomer ratio throughout the process and thus to regulate the molecular weight of the resulting liquid telomer (as well as its molecular weight distribution), the flow rate of catalyst solvent stream in the continuous unit is gradually increased. Thus, volume expansion (and catalyst dilution) during the process is compensated for by an increased process stream flow rate and a constant or essentially constant ratio of organometal initiator or catalyst to monomer is maintained throughout the reaction. The stream volume passing from one reactor unit increases due to the fact that the gaseous taxogen, say 1,3-butadiene gas, is incorporated in the ultimate liquid telomer in the form of polybutadiene which results, therefore, in an increase in the linear velocity of flow from one reactor to the next reactor in any given series of reactors. The dilution of the carbon-metal (say carbon-lithium) concentration in the flowing stream exposed at each succeeding reactor unit to the stream of, say, 1,3-butadiene admitted through the finely perforated area 18 in each reactor is offset by the increased flow rate of the stream thus ensuring that the same number of polybutadiene molecules of equivalent molecular weight is formed in each subsequent reactor unit. After passage through a given number of units, limited on the one hand by the need of full utilization of carbon-metal or carbon-lithium bond and on the other hand by a slowing down of the reaction by further catalyst dilution, the liquid telomer is collected in container 37 and processed further by conventional techniques.

Alternative procedures of termination, washing and solvent stripping of the telomer stream can be made a part of this continuous system, such that finished product in the form of the liquid telomer may be collected and packaged directly.

Temperatures of the chain elongation and transmetalation parts of the system may be varied widely to achieve any particularly desired physical properties; however, it is generally found best to maintain the temperatures of both parts approximately the same. Temperatures may be varied from about 25"C to 1100C, and most advantageously between 45 and 75"C. Coils or jackets or other means can be employed for purposes of temperature control, whether heating or cooling.

Although the process may be conveniently carried out at atmospheric autogenous pressures, the system may readily be adjusted to operate under pressure in excess, and well in excess, of atmospheric pressure if desired.

Many different ingredients can be used as the telogens for the production of the liquid telomers in accordance with the present invention. The term "telogen" as used herein is employed in the same sense and with the same meaning as is set forth in the aforesaid U.S. Patent No. 3,751,501, namely, an aromatic compound, notably an aromatic hydrocarbon, having at least one active hydrogen in a side chain capable of being replaced by a metal atom, particularly lithium, but devoid of any other substituents as, for instance, hydroxyl, chlorine, bromine, iodine, carboxyl and nitro, which substituents are reactive with the organolithium compositions or complexes which are utilized as catalysts. Illustrative examples of such useful telogens are C1-C4 mono-, di- and trialkyl benzenes exemplified by toluene, ethylbenzene, n-propylbenzene, isopropylbenzene, o-, m- and p-xylenes; 1+3,5-trimethylbenzene; n-, s- and t-butylbenzenes; cyclohexylbenzene; alkyl, notably C1-C4 and cycloalkyl substituted polycyclic aromatic compounds exemplified by 1,2,3,4-tetrahydronaphthalene, I-methylnapthalene, 1isopropylnaphthalene, 1,3-isobutylnaphthalene, and l-cyclohexylnaphthalene; alkoxyaromatic compounds exemplified by anisole; 1,3-dimethoxybenzene; monopropoxybenzene; I-methoxynaphthalene and 1,3-dimethoxynaphthalene; dialkylamino-aromatic compounds, notably those in which the alkyl is C1-C4, exemplified by dimethylaminobenzene; 1,3 - bis - (di - isopropylaminobenzene) and l-dimethylaminonaphthalene.

The taxogens which are utilized in the production of the normally liquid telomers which are made pursuant to the present invention include, illustratively, polymerizable monomeric dienes and polymerizable vinyl-substituted aromatic compounds, which advantageously contain from 4 to 12 carbon atoms, typical examples of which are isoprene, 1,3-butadiene, 2-methyl-1,3-butadiene; 2,3dimethyl-l, 3-butadiene; styrene; alpha-methylstyrene; 1,4-divinylbenzene; 1vinylnaphthalene and 2-vinylnaphthalene. Numerous other examples can also be used, many of which are shown, for instance, in U.S. Pat. No. 3,091,606.

The taxogen is contacted in gaseous form with the metalated telogen which is in the form of a liquid as such or in the form of a solution in an inert organic solvent, commonly a liquid hydrocarbon solvent. Illustrative of such solvents are nheptane, n-hexane, n-octane, isooctane, cyclohexane, methylcyclohexane, benzene, etc., and compatible mixtures of any two or more thereof.

The organometals which are utilized as initiators or catalysts in the practice of the continuous process of producing normally liquid telomers in accordance with the invention can be selected from wide groups at least most of which are, per se, known to the art as initiators or catalysts in telomerization and polymerization reactions. Many of them are complexes which are formed in organic solvent solutions or, in use, are dissolved in organic solvent solutions, particularly liquid hydrocarbon solutions. Among said initiators or catalysts are C2-C18 alkyllithiums, or other organolithiums listed below, used either alone or in admixture with alkylmetals of at least one of the metals sodium, potassium, rubidium and cesium, particularly sodium and potassium and. in certain cases, especially potassium.

Illustrative of the organometals used as such, or in the form of complexes, are (a) C3-C6 alkyllithiums in admixture with (b) C3-C6 alkylmetals in which the metals of said alkylmetals are one or more from groups of sodium, potassium, rubidium and cesium, especially the n-butylmetals. However, in one aspect of the broader phases of the invention, the organometals employed in the production of the compositions or complexes or the like utilized in the practice of the present invention can comprise C2-C18 hydrocarbon organo radicals, said organo radicals being, for instance, cycloalkyl, cycloalkenylalkyl, arylalkyl, arylcycloalkyl, cycloalkylaryl, arylcycloalkyl, and the like. Still other types of organo radicals that can be used are those of heterocyclic character, such as 2-pyridyl and 2-thienyl; ethylenically unsaturated organo radicals such as vinyl, allyl and propenyl; polyfunctional organo radicals such alkylene and polymethylenes, as for example, 1,4-tetramethylene and 1,5-pentamethylene, and those derived by addition of alkali metals and alkyllithiums to conjugated polyene hydrocarbons such as isoprene, 1,3butadiene and 1,3-divinylbenzene (see, for instance, U.S. Pats. Nos. 3,294,768; 3,388,178 and 3,468,970). Many of the said organometals which are utilized to produce the compositions or complexes can be represented by the formula X(R)a(Li)b . Y(R1)c(Mc)d where R and R' are the same or dissimilar C2-C18 hydrocarbon organo radicals; Me is one or more metals selected from the group of sodium, potassium, rubidium and cesium; X and Y are integers reflecting the molar ratios of the respective organometals comprising the compositions or complexes, the values of X and Y commonly involved being indicated hereafter; and a, b, c and d are integers, generally from 1 to 3. Illustrative examples of said hydrocarbon organo radicals, in addition to those previously mentioned, are n-propyl; n-butyl; s-butyl; n-amyl; tamyl; n-octyl; n-undecyl; n-decyl; n-dodecyl; 2-methyl-2-butenyl; cyclopentylmethyl; cyclohexyl-ether; cyclopentyl-ethyl; methylcyclopentyl ether; 4-cyclohexenyl-ether; alphanaphthyl-ethyl; cyclopentyl; cyclohexyl; methylcyclopentyl, dimethylcyclopentyl; ethylcyclopentyl; methylcyclohexyl; dimethyl-cyclohexyl; ethylcyclo-hexyl; isopropylcyclohexyl; phenylethyl; phenylcyclohexyl, phenyl;-tolyl; xylyl; benzyl; naphthyl; methylnaphthyl; dimethynaphthyl; ethylnaphthyl; cyclohexylbutyl; 2,7 - dimethylocta - 2,6 - dien 1,8 - yl; 2,6 - dimethylocta - 1,6 - dien - 1,8 - yl; and bis(a - 2 - methylbutyl) m - xylyl. Still other initiators or catalysts useful in the practice of our present invention are R2MgNa (made by admixing MgCl2, NaO-Bu-t, (BuLi); R2Mg (RNa)3 (made from MgCl2, NaO Bu-t, BuLi); R3MgK (made from BgBr2, t-BuOK, BuLi); 4RLi+2NaOt-Bu+MgCl2, wherein the MgCI2 or MgBr2 is advantageously initially activated, and R is lower alkyl.

The compositions or complexes can be of binary character, as in the case, for example, of n-butyllithium . n-butylsodium or n - butyllithium . n - butylpotassium; or of ternary character, as in the case, for example, of n butyllithium . butylsodium . n - butylpotassium or n - butyllithium . n butylpotassium . n - butylcesium. Compositions or complexes of quaternary character can also be utilized.

The initiators or catalysts can also be used in the form of polymetallo, particularly polylithio, hydrocarbon compounds, illustrative of which, in the case of the polylithio hydrocarbon initiators or catalysts, are dilithioisoprene; dilithiobutadiene; 2,4-dilithio, 2,4-diphenylhexane; 1,4 - dilithio - 1,1,4,4 tetraphenyl - butadiene and 1,8 - dilithio - 2,3,6,7 - tetramethyl - octa - 2,6 diene, and other dilithio adducts of other polyene hydrocarbons as shown, for instance, in U.S. Pat. No. 3,388,178. Still other polylithio hydrocarbons which can be used are alkylene dilithiums such as 1,4-dilithiobutane; 1,5-dilithiopentane; 1,6dilithiohexane, as well as such dilithio compounds as 4,4-dilithiobiphenyl; polylithio hydrocarbons in which there are 3 or 4 lithiums in the molecule are shown, for instance, in U.S. Pat. No. 3,377,404. As shown in said U.S. Pat. No.

3,377,404 the polylithioorganics therein described can be identified by the formula RLiX where x is an integer from 2 to 4, and R is a hydrocarbon radical selected from aliphatic, cycloaliphatic and aromatic radicals. It is especially desirable to utilize dilithio adducts of such conjugated polyene hydrocarbons as isoprene and 1,3butadiene in those instances in which the initiator or catalyst selected for use is a di-or poly-lithio hydrocarbon compound.

The soluble metalorganic complexes referred to above comprise compositions in which the organolithium to (other) organo-alkali molar ratios may vary considerably depending on the nature of the organoradicals involved. Generally, these ratios will vary from about 2:1 to about 10:1 for complexes containing alkyl groups such as n-butyl-, s-butyl-, or n-amyl-, but may be as high as about 100:1, 500:1 and even as high as about 1000:1 for complexes containing one or two organo groups derived from the addition of alkali metals to conjugated polyenic hydrocarbons such as 1,3-butadiene or isoprene. Especially preferred ratios utilized are those in which the molar ratios of organolithium to other organo-alkali vary from about 3:1 to about 10:1.

It is also desirable, in certain instances, to utilize, in the reaction medium in which the telomers of the present invention are produced, certain types of catalysts, namely, Lewis base ethers and aliphatic tertiary amines. Illustrative examples of such ethers are linear alkyl ethers such as dimethyl ether, diethyl ether, diisopropyl ether, di-n-butyl ether and diisobutyl ether; dialkyl ethers of aliphatic polyhydric alcohols such as dimethyl ether of ethylene glycol, diethyl ether of ethylene glycol, diisopropyl ether of ethylene glycol and diisopropyl ether of diethylene glycol, and dimethyl-, diethyl- and diisopropyl ethers of propylene glycol; cyclic alkyl ethers such as tetrahydrofuran (THF), tetrahydropyran (THP), dioxane, and 7-oxa[2,2,l]bicycloheptane (OBM); and liquid ethers in the form of azaoxa-alkanes, azo-alkyloxacycloalkanes or oxa-alkylazacycloalkanes which can be represented by the formulae:

where Rg, R2 and R3 are the same or different alkyls each containing from 1 to 4 carbon atoms, namely, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl and tbutyl; X is a non-reactive group as -CH2CH2-; -CR 2-C112-CH2-,

or other divalent aliphatic hydrocarbon or alkylene radical, preferably containing from 2 to 4 carbon atoms; and w is 1 to 4. Illustrative examples of such ethers include, for instance, 2-dimethylaminoethylmethyl ether [(CR3)2-N-CH- CH2-O-CH3l; 2-dimethylaminoethylmethyl ether [(C2H5)2-N-CH2-CH2)- CR3]; and 2-dimethylaminopropylmethyl ether [(CH3)2-N-CH2-CH2-CH3- 0-CR3]. An illustrative dioxacycloalkane is 2,2'-di-(tetrahydrofuranyl)

The Lewis base aliphatic tertiary amines include, by way of illustration, trimethylamine, triisopropylamine; and ditertiary amines such as N,N,N',N' tetramethylenediamine. Other suitable Lewis base tertiary amines which can be utilized are disclosed in U.S. Patents Nos. 3,206,519 and 3,451,988. Especially suitable, where such cocatalyst is used, are N,N,N',N'-tetramethylethylenediamine (TMEDA) and 1 - dimethylamino - 2 - ethoxyethane (2-dimethylaminoethyl ethyl ether).

The following examples show illustrative runs in accordance with the invention in the apparatus shown in the accompanying drawing. It will, of course, be understood that numerous other normally liquid resinous telomers can be made utilizing different telogens, different taxogens, different metalorganic initiators or catalysts, proportions of reactants, etc. It will, of course, be understood that such materials as oxygen, carbon dioxide and water, as contaminants or otherwise, as well as other certain materials, are significantly detrimental or destructive to the carrying out of the production of the liquid telomers. Hence, such materials should be removed from the reactants, which can be done by known procedures, and should be kept out of the system in which the desired reactions are taking place in the practice of the present continuous process.

EXAMPLE 1 4500 ml toluene (distilled from an n-butyllithium solution in toluene), 23 g concentrated n-butyllithium (0.36 moles) and 21.1 g potassium t-butoxide (0.18 moles) are premixed in tank 10 to provide a solution having a temperature of about 60"C. The metering pump 11 is started (flow rate of 90 minute) and the gaseous 1,3-butadiene feed rate is set for reactor 13 by flow meter 24 at 9 g/minute. As the aforesaid continuously flowing toluene solution reaches each reactor, reaction with the gaseous 1,3-butadiene occurs, being initiated in the annular area adjacent the finely perforated section 18. The gaseous 1,3-butadiene feed rate is set for each of the three reactors. After 12 minutes, each reactor comes to a temperature of 70"C.

The reactors are cooled when necessary in order to maintain a temperature of about 70"C. After 15 minutes, collection of the sample is begun. The sample (2600 ml) is collected for a period of 15 minutes. The 1,3-butadiene feed is then stopped and the reactor washed with dry toluene, flushed with nitrogen and sealed. The sample is terminated and washed twice with methanol (equal volumes of liquid telomer and methanol). The polymer layer is then dried under vacuum. A clear liquid telomer (381 g) is obtained as the final product. Its physical properties are as follows: Mn (VPO) = 950 Viscosity (poise at 250 C) (Engler) = 4.2 Volatiles /,, = 1.9* Base No. (Mg KOH/g) = 0.1 Microstructure (I.R.) = 42V Vinyl 2707o Trans 31 /" Cis & Sat *Wt. loss at 2000 C, 5 minutes, in air.

EXAMPLE 2 4500 ml toluene (distilled from an n-butyllithium solution in toluene), 24 g concentrated n-butyllithium (0.375 moles) and 43.2 g TMEDA (0.375 moles (distilled from an n-butyllithium solution in TMEDA) are premixed in tank 10 to produce a solution having a temperature of 60"C. The procedure than carried out is. the same as described in Example 1 except that the reaction temperature in each reactor unit is maintained at about 90"C. A total sample is collected in the amount of 3380 ml and when stripped yields 472 g of a liquid telomer having the following physical properties: Mn (VPO) = 1300 Viscosity (poise at 250C) (Engler) = 55.7 Volatiles % = 2.9* BaseNo.(MgKOH/g) = 0.18 Microstructure (I.R.) = 48 /,, Vinyl -14 Trans 38% Cis & Sat *Wt. Loss at 2000 C, 5 minutes, in air.

Additional specific normally liquid telomers, which represent particularly preferred embodiments of the present invention, can be made in accordance with the continuous process, utilizing the following overall formulations or total of ingredients in the stated proportions, etc., in suitably sized apparatus: EXAMPLE 3 193 kg toluene 623 kg n-hexane 43 gram equivalents n-butyllithium 21.5 gram equivalents potassium t-butoxide 1555 kg 1,3-butadiene Reaction temperature 500C EXAMPLE 4 864 kg toluene 42 gram equivalents TMEDA 73 gram equivalents dilithioisoprene 1591 kg 1,3-butadiene Reaction temperature 720C EXAMPLE 5 364 kg toluene 455 kg benzene 48 gram equivalents n-butyllithium 21.5 gram equivalents potassium t-butoxide 1.29 gram equivalents nickel acetylacetonate dissolved in 45.4 kg benzene 2041 kg 1,3-butadiene Reaction temperature 500C EXAMPLE 6 859 kg toluene 43 gram equivalents n-butyllithium 21.5 gram equivalents potassium t-butoxide 1441 kg 1,3-butadiene 341 kg a-methylstyrene A series of additional runs is made, in each case in accordance with our continuous process and with a corresponding separate run utilizing the batch type process of U.S. Patent No. 3,751,501, with the same ingredients, the same proportions thereof, the same reaction temperatures, and the same after-treatment to recover the liquid telomers in the continuous and the batch type runs. The following Table I shows a comparison of various properties of the normally liquid telomers of the continuous telomerization runs in accordance with the invention in relation to those following the aforesaid batch type procedure.

TABLE I Viscosity Liquid Continuous (Poise at Telomer Telomer or Mn 25"C) Run No. Type Batch (VPO) (Engler) (MWD 3372 A Continuous 1300 56 1.26 54 A Batch 1650 730 1.66 3298 A Continuous 2300 724 1.50 53 A Batch 2300 7000 1.66 3439 P Continuous 1300 10* 1.39 75 P Batch 1300 6.4** 1.70 3420 P Continuous 2000 22 1.26 85 P Batch 2500 70 1:98 Wt. loss 0.35 /O at 2000 C, 5 minutes, in air.

**Wt. loss 4.8 /" at 200"C, 5 minutes, in air.

The foregoing data in Table I show that, in all cases, the normally liquid telomers produced by the invention of our continuous process have a lower molecular weight distribution, commonly about 10 to about 35 /" lower, than those normally liquid telomers produced by the prior known batch type process using the same ingredients in the same proportions and under the same temperature conditions; as well as differences, generally, in other respects. In most cases, the lower MWD is reflected in lower viscosities. In the case of P type telomers, the high weight loss of the batch run P liquid telomers is due to an appreciable amount of very low molecular weight telomers, which explains the low visocosities in such P type liquid telomers. Commonly the viscosities of the liquid telomers, especially of the A type liquid telomers, measured in poises at 250C (Engler), produced by the continuous process of the present invention, are from about 1/10 to about 1/2 those produced by the batch process utilizing the same ingredients in the same proportions and under the same temperature conditions. The nature of the A and the P type liquid telomers referred to in the above Table I and the following Tables II and III is described hereafter.

We have referred to above to the fact that our invention results in the production of normally liquid telomers, particularly those which are in the form of telomeric polybutadiene oils, which are characterized by a significant reduction in the volatiles content thereof (at comparable molecular weights), in comparison with the otherwise generally corresponding liquid telomers when made by batch type processes as disclosed in such U.S. Patents as Nos. 3,678,121 and 3,751,501.

An additional improvement, closely allied to that of a lower volatiles content, is the more narrow molecular weight distribution (MWD) of the liquid telomers obtained by the employment of our telomerization process as compared to the batch type process, which leads to lower viscosities at equivalent molecular weights and a greater ease in handling of such higher molecular weight products. This is shown in the following Table: TABLE II Comparison of Batch vs Continuous Telomerization Runs Liquid Telomer Telomer Batch or Volatiles Run No. Type Continuous (%)* Mn (VPO) 75 P Batch 4.8 1300 3416 P Continuous 0.35 1300 3431 P Continuous 0.2 1150 3446 P Continuous 0.3 1450 3447 P Continuous 0.4 1200 3420 P Continuous None 2000 97 P Batch 1.2 3050 54 A Batch 0.5 1600 3298 A Continuous None 2300 *Wt. loss at 2000C, 5 minutes, in air.

The above date show not only that liquid telomers prepared via our continuous process have decidedly less volatiles than similar liquid telomers prepared by a batch type process, but, in fact, at the higher Mn liquid telomers, no volatiles are detected.

A still further and important advantage of the invention over the heretofore known batch type process, as exemplified in U.S. Patent No. 3,751,501, centers about when is referred to here as Unit Volume Production Capacity (C) the definition of which is in weight of liquid telomer produced over time over volume of reactor capacity or in kg/hr/reactor-liter In both laboratory-size equipment and in pilot plant production equipment, in batch operations, production of certain normally liquid telomers, the C values have commonly and quite consistently overall averaged approximately 0.037 kg/hr/reactor-liter for so-called P system liquid telomers, and 0.056 kg/hr/reactorliter for so-called A system liquid telomers. The P system liquid telomer resins, briefly stated, involve the preparation of a mixture of toluene, hexane, nbutyllithium and potassium t-butoxide into which mixture there is then passed gaseous 1,3-butadiene at a controlled rate, followed by purging the system, after the completion of the telomerization reaction, with nitrogen, and treatment with methanol to remove catalyst residues followed by stripping and recovery of the normally liquid telomers. The A system liquid telomer resins briefly stated, involve the preparation of a mixture of toluene, TMEDA and dilithiodiisoprene into which mixture there is then passed gaseous 1,3-butadiene at a controlled rate, followed by similar steps to those referred to above in connection with the P system liquid telomer resins.

The following Table III shows data obtained in the production of normally liquid telomer resins utilizing the continuous process of the present invention carried out in laboratory-size equipment in relation to the liquid telomers of the aforesaid P and A systems: TABLE III Continuous g/min of 1,3 Reactor Butadiene kg/hr/reactor Run No. System Vol (ml) Absorbed liter 3538 P 500 18.6 2.23 3343 P 500 17.2 2.06 3352 P 500 26.2 3.14 3353 P 500 21.7 2.60 3280 P 1000 34.0 2.04 3347 A 500 17.9 2.05 3300 A 1000 22.0 1.32 As noted above, the C value in the P liquid telomer resin system in pilot plant scale batch operation has commonly been about 0.037 kg/hr/reactor-liter.

In the continuous process of our present invention, in the production of the P liquid telomer resin system, the continuous system on the average absorbs about 25 g of gaseous l,3-butadiene/minute/500 ml, or 25x60 =3 kg/hr/reactor-liter 500 or, in other words, the continuous system of the invention is approximately 80 times more effective and faster.

Similarly, as noted above, the C value in the A liquid telomer resin system in pilot plant scale batch operation has commonly been about 0.056 kg/hr/reactorliter.

In the continuous process of our present invention, in the production of the A liquid telomer resin system, the continuous system on the average absorbs about 16 g of 1,3-butadiene/minute/500 ml, or 16x60 =1.92 kg/hr/reactor-liter 500 or, in other words, the continous system of our invention is approximately 34 times more effective and faster.

The foregoing C values have been obtained where our continuous process has been used in what is essentially laboratory size equipment. This laboratory size equipment has ranged in size, as to the reactors, in which the reactor volume or capacity or the amount of the reaction medium in each of the reactors 13, 31 and 33 has, in certain cases, been about 500 ml; and, in other cases, approximately 1000 ml. In other words, the reactor-volume in each of said reactors was the volume of the annular space 17 (in reactor 13) and similarly in the other reactor or reactors utilized. The diameters of the cylindrical tube 14 and the inner cylinder 16 are variable and the same is true as to the height thereof. Illustrative is a diameter of 4 to 4 1/2 inches of the cylindrical tube 14; a diameter of 2 1/2 to 3 inches of the inner cylinder 16; and a height of said tubes ranging from about 10 to 20 inches.

In the comparisons set forth above in arriving at the values of C, it will be understood, and as indicated, the reactor-liter (or reactor-volume) figure was arrived at by comparing the volume of the annular space in the number of reactors used in the continuous process with the volume of the reactor used in batch type runs according to U.S. Patents Nos. 2,678,121 and 3,751,501. The volume of the batch reactor was the volume of the liquid phase or material at the end of the telomerization reaction. Based on extrapolations, and also based on tests, this means that very much greater production of liquid telomers per unit of time per unit of volume of the continuous reactor are obtained than where the liquid telomers are made by a batch process. Expressed otherwise, much smaller reactor equipment volume according to the practice of our invention is required to produce the same weight of liquid telomer than where the batch production of liquid telomer is used.

It will be understood, of course, that the apparatus used for the carrying out of the present continuous process can be scaled up to any reasonable extent desired within reasonable limits and consistent with established engineering principles.

Although the telomers produced, for instance, in accordance with U.S.

Patents Nos. 3,678,121 and 3,751,501 have commerical utility for a variety of purposes, as described in said patents, as generally noted above, those of said telomers which are on the low molecular weight side commonly contain a relatively appreciable percentage of volatile components arising predominantly from the somewhat broad molecular weight distributions encountered in such telomerization reactions in which both transmetalation and polymerization processes are occurring simultaneously or substantially so. Such volatile components in the liquid telomers are detrimental in processing these telomers for can or coil coating applications. The volatile components are oxidized rapidly in air during curing above 1000C, producing noxious fumes and generally contributing to pollution. In the practice of our continuous process, the telomers, and notably the telomeric polybutadiene oils which are produced, are generally characterized by a substantially lower content, commonly from about 1/10 to 1/2, of undesirable volatile components, than are present in liquid telomers produced by a batch process utilizing the same ingredients in the same proportions and under the same temperature conditions, the volatiles content being measured by heating the telomer at 2000C for 5 minutes, in air.

The normally liquid telomers can be. made to correspond to particular molecular weights or ranges or molecular weights, particular viscosities, and of variable microstructures in order to possess properties to fill particular needs.

Thus, and as disclosed in the aforementioned U.S. Patent No. 3,751,501, for certain applications such as "potting" or "casting", liquid telomers of relatively high molecular weight, for instance, about 1500 to about 3000, are desirable to obtain good cures. On the other hand, for certain other applications, such as pollutionfree paints and coatings, distinctly lower molecular weight liquid telomers, for instance, about 145 to about 460, are particularly useful since it is unnecessary to resort to the use of admixed solvents to effect lowering of viscosity. There are many other utilities for low molecular weight liquid telomers as, for instance, plasticizers for rubbers, alkylates, and the production of biodegradable synthetic detergents.

WHAT WE CLAIM IS: 1. A continuous process for producing normally liquid telomers, wherein a solution is formed comprising an organo-metal initiator and a liquid telogen (as hereinbefore defined) whereby the liquid telogen is metalated, and the solution is continuously passed through a plurality of reaction zones in each of which the solution is reacted with at least one gaseous taxogen which is selected from conjugated dienes and vinyl-substituted aromatic compounds, and wherein the gaseous taxogen is introduced into each reaction zone continuously as a control stream through fine apertures in a tubular member spaced from a wall and thereby defining a passageway so as to come into direct contact with the initial solution, in the case of the first reaction zone, or the resulting mixture which has left the previous reaction zone in the case of the second and any subsequent reaction zone, liquid telomer being recovered from the final reaction zone.

2. A process as claimed in claim 1, in which polymerization of the taxogen occurs in each reaction zone, and in which the initial solution or the resulting mixture leaving a reaction zone is metalated prior to its entry into the first and subsequent reaction zones.

3. A process as claimed in claim 1 or 2, in which the telogen is toluene and the taxogen is 1,3-butadiene.

4. A process as claimed in any one of claims 1 to 3, in which the initiator is an organolithium.

5. A process as claimed in any one of claims 1 to 4, in which the organometal initiator comprises a complex of n-butyllithium and potassium t-butoxide.

6. A process as claimed in any one of claims 1 to 4, in which the organometal initiator comprises a complex of n-butyllithium and N,N,N',N'tetramethylethylenediamine.

7. A process as claimed in any one of claims I to 4, in which the organometal initiator comprises a complex of dilithiodiisoprene and N,N,N',N'tetramethylethylethylenediamine.

8. A process as claimed in any one of claims 1 to 7, in which the organometal initiator and liquid telogen are dissolved in an inert organic solvent.

9. A process as claimed in any one of claims 1 to 8, in which said fine apertures having a size corresponding to a diameter in the range of 2 to 40 microns.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (25)

**WARNING** start of CLMS field may overlap end of DESC **. Although the telomers produced, for instance, in accordance with U.S. Patents Nos. 3,678,121 and 3,751,501 have commerical utility for a variety of purposes, as described in said patents, as generally noted above, those of said telomers which are on the low molecular weight side commonly contain a relatively appreciable percentage of volatile components arising predominantly from the somewhat broad molecular weight distributions encountered in such telomerization reactions in which both transmetalation and polymerization processes are occurring simultaneously or substantially so. Such volatile components in the liquid telomers are detrimental in processing these telomers for can or coil coating applications. The volatile components are oxidized rapidly in air during curing above 1000C, producing noxious fumes and generally contributing to pollution. In the practice of our continuous process, the telomers, and notably the telomeric polybutadiene oils which are produced, are generally characterized by a substantially lower content, commonly from about 1/10 to 1/2, of undesirable volatile components, than are present in liquid telomers produced by a batch process utilizing the same ingredients in the same proportions and under the same temperature conditions, the volatiles content being measured by heating the telomer at 2000C for 5 minutes, in air. The normally liquid telomers can be. made to correspond to particular molecular weights or ranges or molecular weights, particular viscosities, and of variable microstructures in order to possess properties to fill particular needs. Thus, and as disclosed in the aforementioned U.S. Patent No. 3,751,501, for certain applications such as "potting" or "casting", liquid telomers of relatively high molecular weight, for instance, about 1500 to about 3000, are desirable to obtain good cures. On the other hand, for certain other applications, such as pollutionfree paints and coatings, distinctly lower molecular weight liquid telomers, for instance, about 145 to about 460, are particularly useful since it is unnecessary to resort to the use of admixed solvents to effect lowering of viscosity. There are many other utilities for low molecular weight liquid telomers as, for instance, plasticizers for rubbers, alkylates, and the production of biodegradable synthetic detergents. WHAT WE CLAIM IS:

1. A continuous process for producing normally liquid telomers, wherein a solution is formed comprising an organo-metal initiator and a liquid telogen (as hereinbefore defined) whereby the liquid telogen is metalated, and the solution is continuously passed through a plurality of reaction zones in each of which the solution is reacted with at least one gaseous taxogen which is selected from conjugated dienes and vinyl-substituted aromatic compounds, and wherein the gaseous taxogen is introduced into each reaction zone continuously as a control stream through fine apertures in a tubular member spaced from a wall and thereby defining a passageway so as to come into direct contact with the initial solution, in the case of the first reaction zone, or the resulting mixture which has left the previous reaction zone in the case of the second and any subsequent reaction zone, liquid telomer being recovered from the final reaction zone.

2. A process as claimed in claim 1, in which polymerization of the taxogen occurs in each reaction zone, and in which the initial solution or the resulting mixture leaving a reaction zone is metalated prior to its entry into the first and subsequent reaction zones.

3. A process as claimed in claim 1 or 2, in which the telogen is toluene and the taxogen is 1,3-butadiene.

4. A process as claimed in any one of claims 1 to 3, in which the initiator is an organolithium.

5. A process as claimed in any one of claims 1 to 4, in which the organometal initiator comprises a complex of n-butyllithium and potassium t-butoxide.

6. A process as claimed in any one of claims 1 to 4, in which the organometal initiator comprises a complex of n-butyllithium and N,N,N',N'tetramethylethylenediamine.

7. A process as claimed in any one of claims I to 4, in which the organometal initiator comprises a complex of dilithiodiisoprene and N,N,N',N'tetramethylethylethylenediamine.

8. A process as claimed in any one of claims 1 to 7, in which the organometal initiator and liquid telogen are dissolved in an inert organic solvent.

9. A process as claimed in any one of claims 1 to 8, in which said fine apertures having a size corresponding to a diameter in the range of 2 to 40 microns.

10. A process as claimed in any one of claims 1 to 9, in which the rate of

admision of the taxogen to each of said reaction zones is maintained substantially constant.

11. A process as claimed in any one of claims 1 to 10, in which the initiator to taxogen ratio is controlled to maintain it substantially constant throughout the process of forming said liquid telomers.

12. A process as claimed in any one of claims 1 to 11, in which the process is controlled whereby substantially the same number of molecules of polymerised taxogen of equivalent molecular weight is formed in each of the reaction zones.

13. A process as claimed in any one of claims 1 to 12, in which there are three reaction zones.

14. A continuous process for producing normally liquid telomers, substantially as hereinbefore described with reference to the accompanying drawings and/or in any one of the foregoing Examples.

15. A normally liquid telomer prepared by the continuous process claimed in any preceding claim and having a viscosity substantially lower than the viscosity, measured in poises at 250C, of a liquid telomer made by a batch process utilizing the same ingredients in the same proportions and under the same temperature conditions.

16. A telomer as claimed in claim 15, in which the viscosity of the liquid telomer prepared by the continuous process is from about 1/10 to about 1/2 that of the liquid telomer prepared by the batch process.

17. A telomer as claimed in claim 15 or 16, which has a volatiles content substantially lower than the volatiles content, measured by heating said telomer at 200"C for 5 minutes, in air, of the liquid telomer made by the batch process.

18. A telomer as claimed in any one of claims 15 to 17, which has a molecular weight distribution substantially lower than the molecular weight distribution of the liquid telomer made by the batch process.

19. A telomer as claimed in claim 18, in which the molecular weight distribution of the liquid telomer prepared by the continuous process is from 10 to 35% lower than that of the liquid telomer prepared by the batch process.

20. Apparatus for producing normally liquid telomers by the process claimed in any one of claims 1 to 14, comprising means for continuously passing a controlled stream of a solution comprising a liquid telogen metalated by an organometal initiator through a plurality of reaction zones each defined by ,a tubular member and a wall spaced from the tubular member, each tubular member having fine apertures extending therethrough, means for continuously passing a controlled stream of a gaseous taxogen through said fine apertures into each reaction zone and initially into direct contact with liquid therein, means connecting each reaction zone with a subsequent reaction zone to permit liquid to flow from one reaction zone to the next, and means for recovering liquid telomer from the final reaction zone.

21. Apparatus as claimed in claim 20, in which the fine apertures correspond to openings having a diameter in the range of about 2 to 40 microns.

22. Apparatus as claimed in claim 20 or 21, which includes means for maintaining the rate of admission of the gaseous taxogen substantially constant into each reactor.

23. Apparatus as claimed in any one of claims 20 to 22, in which the tubular members and walls define vertically extending annular reaction zones and the fine apertures are disposed in the lower part of each tubular member.

24. Apparatus as claimed in any one of claims 20 to 23, in which there are three reaction zones.

25. Apparatus for producing normally liquid telomers substantially as hereinbefore described with reference to the accompanying drawing.