Патент USA US2403966код для вставки
2,403,966 Patented July 16, 1946 UNITED STATES PATENT OFFICE 2,403,966 POLYMER SLURRY PROCESS and Irving E. John R. Brown, Jr., West?eld, to Stand Lightbown, Cranford, N. J ., assignors ard Oil Development Company, a corporation of Delaware No Drawing. Application October 14, 1942, Serial No. 461,986 8 Claims. This invention relates to polymerization proc esses and rubber-like polymers; relates particu larly to processes for the interpolymerization of iso-ole?ns and diole?ns; and relates especially to the polymerization of ole?nic material in the presence of non-reactive components for main taining the solid polymer in a ?nely dispersed (Cl. 260-8) 2 When the polymer is prepared in the presence of substantial quantities of a diluent or diluent refrigerant such as liquid ethylene, it is only slightly sticky at the polymerization temperature, and is only slightly sticky at room temperature when moistened with water; but at temperatures . in the range from about -55° C. to about -—20“ C., it is extremely sticky and it shows a very great tendency to coalesce into large coherent masses, and to adhere to surfaces with which like polymers are produced by the polymerization 10 it comes into contact. In other methods of prep or 'interpolymerization of an iso-ole?n such asiso aration, where small quantities only of diluent. butylene, with or without a diole?n such as bu or no diluents are present, the material is ex tadiene, isoprene, pentadiene, dimethyl butadi tremely sticky at the polymerization temperature, condition. '. . It is known in the art that synthetic rubber ene, or the like. The polymerization reaction is and at the intermediate intervening tempera conducted at temperatures ranging from about 15 tures and is troublesomely sticky at room tem C. or lower, and —40° C. or —78° C. to -l60°' perature in water. These characteristics of the consists in the mixing of the lique?ed ole?ns with newly polymerized material interfere seriously a lique?ed diluent-refrigerant such as liquid eth with the handling of the product and with the ylene or with a refrigerant such as solid carbon complete removal of spent and surplus catalysts, 20 dioxide with or without a higher boiling diluent. since the sticky character 01' the interpolymer To the rapidly stirred mixture is then added, causes it to adhere to the treating apparatus, preferably by spraying onto the surface, a cat and to cohere in relatively large lumps, contain alyst consisting of aluminum chloride or similar ing occluded catalysts which cannot be washed metal halide dissolved in a suitable solvent such out or removed in subsequent operations. as carbon disul?de or the low-freezing alkyl It is anobject of the invention to eliminate halides. The resulting polymer has a molecular these undesirable characteristics from the inter weight ranging from 20,000 to 150,000 or above, polymer and to obtain fine particle suspensions has an iodine number ranging from 0.1 to 40, or slurries by adding into the reaction mixture. preferably between 0.5 and 10, depending upon 30 either prior to the polymerization reaction or the quantity of diole?n interpolymerized into the prior to the fiashring operation but preferably polymer; and in addition the polymer has the prior to the polymerization reaction, a small capability of reacting with sulfur, in spite of its quantity of an inert material in order to coat very ‘low iodine number, to develop an elastic the solid particles of interpolymer formed so as limit in the material, a tensile strength ranging to keep them in a dispersed condition during the from 2500 lbs. to 4500 lbs/sq. in., an ultimate 35 subsequent operations; which material may later elongation ranging from 500% to 1200%, and a be washed out of the polymer if desired. This high abrasion and fiexure resistance. The result material serves as a' de?oculating agent to pre ing material, while not a true synthetic rubber vent the undesired cohesion and adhesion of the in any way, is a high-grade substitute for rub 40 polymer throughout its processing. ber, possessing many advantages over rubber. A further object of the present invention is to The polymer is a plastic, elastic solid, but it provide a new and useful combination of proc has been found exceedingly diiilcult to obtain essing steps for the treatment of low tempera the solid polymer during the interpolymerization ture interpolymers to obtain and maintain the reaction in the form of small particle aggregates solid interpolymers in the form of ?ne-grained with a physical structure adapted for eii‘lcient 45 slurries. A further object is the slurrying of the and convenient processing through such subse interpolymers in water, and the maintenance of quent steps as the ?ashing of! of unreacted ole the slurry during subsequent processing, includ ?nic material, diluent and refrigerant; and wash ing dry and subsequent mechanical working and ing out of spent catalyst or residual catalyst. milling operations. Likewise, it is dimcult to prevent cohesion be 60 The objects of the invention are accomplished tween the particles 01' the interpolymer, and to ' by the incorporation into the reaction mixture prevent adhesion of the particles or interpoly prior to the interpolymerization reaction or an mer to the reactor, to the supporting screen in inert de?occulating material in the form of a the drier, and other metal objects with which 55 fine powder which may comprise inert powders the interpolymer comes in contact. ' 9,408,988 4 such as talc, whiting, zinc oxide, other pigments or various inorganic ?llers, colloidal clays, such / other means; the water being preferably quite warm to supply the necessary heat of vaporiza as bentonlte, kieselguhr and the like; and other tion for the residual volatile components of the swellable materials such as powdered gelatine, reaction mixture. This process step results in powdered gum tragacanth, gum arabic and the the formation of a relatively ?ne-grained slurry like. Other objects and details of the invention of , the polymer in water, which is particularly will be apparent from the following description. advantageous to handle, since the de?occulating In practicing the present invention, the steps agent prevents coalescence of the particles dur of preparing a reactive mixture of the desired ole ing the warming-up procedure, and similarly pre ?nic material at the desired low temperature is in 10 vents adhesion of the particles to the container. accordance with the steps as taught in Australian The resulting polymer slurry in water is readily Patent No. 112,875, issued to R. M. Thomas and processed by any of a number of subsequent steps. W. J. Sparks or in the corresponding U, S. Patent The polymer slurry is readily separated from the 2,356,128, issued Aug. 22, 1944 to Thomas and water merely by straining out the polymer, and sparks. 15 the fine grains of polymer are readily dried to re Broadly these steps comprise mixing in the move both the water and residual traces of dilu proper proportions an iso-ole?n containing 4 to 8 ent and reactants, by treatment in a drying oven. Alternatively. the polymer may be washed in a capable of interpolymerization with an isoole?n kneader or on the mill as desired, using substan and containing 4 to 12 carbon atoms such as bu 20 tial quantities of water (preferably warm), to tadiene, isoprene, 2,3-dimethyl-l,3 butadiene; pi remove the deflocculating agent and the residual perylene, or a non-conjugated diole?n such as 2~ traces of reaction mixture; as well as to destroy methyl-hexadiene-1,5; 2,6-dimethyl - hexadiene~ any residual traces of catalyst. When gelatine or 1,5; or triole?ns such as hexatriene, myrcene; 1,6 other aqueous colloids are used, they are water dimethyl-heptatriene-l,3,5 and 2,4,6-trimethyl 25 soluble and are very readily removed from the carbon atoms such as isobutylene with a diole?n ' 1,3,5-hexatriene, or the like and cooling the mix ture by internal refrigeration by means of solid carbon dioxide or external refrigeration, e. g., by liquid ethylene, to a temperature ranging from -80° C. to —-100° C. or as low as —160° C. polymer, together with the catalyst and volatile reaction mixture components by a relatively short, simple and easy washing operation. In the case of the pigment type of de?occulating 30 agent, the removal is not so readily accomplished, To this mixture there is then added a small _ although, particularly in the case of the bentonlte quantity of a pulverant or comminuted, inert, de type of clays and the talc, a major portion of the ?occulating material selected from the class con pigment may be removed by a reasonable amount sisting of inert powders such as talc, whiting, cal of washing in the kneader or on the mill. cium silicates, zinc oxide pigments, inorganic ?ll 35 It is of course advantageous to use pigments ers, colloidal clays such as bentonlte, kieselguhr which may be retained in the polymer to avoid and the like; or a swellable aqueous colloid such the necessity of prolonged washing; or, if a poly--' as gelatine or gum tragacanth or gum arable or mer free from de?occulating agents is desired, it powdered agar or the like. The inert material is of course preferable to use the aqueous colloid may be added as such in a pulverant form or may 40 type of material. In either instance, the poly be dispersed in methyl chloride or in the feed. mer may be dried and milled to prepare it for After the inert material has been thoroughly dis further use. persed in the reaction mixture, there is then added a Friedel-Crafts type catalyst; which may be boron ?uoride or aluminum chloride in solu tion in an inert low-freezing solvent such as ethyl or methyl chloride or other similar active halide materials. This polymerization reaction is con ducted under conditions to give a ?nely grained form of interpolymer which is highly desirable, in order to permit the maximum speed of process log the solid interpolymer in subsequent oper- - Era'mple I An ole?nic mixture consisting of 495 parts by volume of isobutylene and 5 parts by volume of isoprene (70% purity) was diluted with 1000 parts by volume of liquid ethylene. To this mixture there was then added 10 parts (by weight) of a good grade of talc in the form of a hydrous mag-‘ nesium silicate having a soft, greasy touch, which is available in various grades; such as potstone, ations. steatite or French chalk. The mixture was pre The catalyst may be any convenient Friedel pared in a reactor equipped with stirring means, Crafts catalyst as is indicated by N. 0. Calloway 55 and provided with a cover to avoid contact with in his article on the “Friedel-Crafts synthesis” the air and to confine the volatilized portions of printed in the issue of "Chemical Reviews,” pub the mixture. The reactor was carefully insulated lished for the American Chemical Society at Bal to reduce the rate of heat in?ow and to reduce timore in 1935; volume XVII, No. 3, the article the volatilization of the ethylene refrigerant. beginning on page 327; the list of useful Friedel 60 The catalyst was prepared by dissolving commer Crafts catalysts being particularly well shown on cial anhydrous aluminum chloride in methyl page 375. For the solvent, any of the mono- or poly-aliphatic halides having less than about_ three or four carbon atoms are useful; the com pounds having carbon atoms above about 2, re quiring special low-temperature technique to pro duce a satisfactory catalyst solution, and the mono~halides being preferred. In addition, such solvents as carbon disul?de are also useful. chloride at the boiling point of the methyl chlo ride to yield a nearly saturated solution contain ing about 1.0% of materials calculatedas alumi num chloride. This solution was then diluted with an additional amount of methyl chloride to produce a, solution containing 0.5% of dissolved aluminum chloride. This solution was then pre cooled to -'78° C. and applied through a spray When the polymerization reaction has reached 70 nozzle'onto the surface of the vigorously stirred ole?nic mixture. The polymerization proceeded rapidly and was approximately 80% complete in about 5 to 7 minutes. entire reaction mixture may be mixed quickly The intenpolymer was formed in the reactor as with water, in a vigorously stirred tank, or by 75 a ?ne-particle slurry in the residual liquid, par a desired stage of completion, the unreacted ma terials are separated from the residual polymer ization mixture in any convenient manner. The ' 2,408,900 5 of tine, inert powders, which will serve to prevent agglomeration of the polymer particles. The tlcularly in the ethylene. The slurry was then dumped into a ?ash tank for the final separation group includes such substances as rouge, clay, or the interpolymer and the diluent-refrigerant, whiting, zinc oxide, chromite. vermiilion, and many other inert, ?nely powdered pigments. Ex and it was found to retain its fine-particle char acter with no perceptible tendency to coalesce in ample III shows a second class of substances to large aggregates. The solid interpolymer. after thorough washing with water and drying which, like the colloidal class, tends to swell up and disperse the material in the presence of was found to have a molecular weight of 80,000. This molecular weight was satisfactory, and the polymer was suitable for compounding and our water. These materials are the mineral ?llers prepared from such substances as the diatoma ceous earth materials of silicious origin known to the trade as “Celite”; and include the intusorial ing with non-sulfur vulcanizing agents of the type of qulnone dioxime to give desirable vulcan earths and clays oi the hydrous-silicate-of-alu izates: and the interpolymer material was found mina type. Example IV shows an organic col to be in a particularly advantageous form for loid having powerful swelling properties which 15 subsequent processing. including such steps as is representative of a considerable number oi! sub drying with hot air and for mechanical working stances including gelatine, gum tragacanth, gum on the mill. arabic, agar-agar, and tannin. Example I! Other inert anticoalescing materials, enumer ated above and illustrated by the present Example I was repeated with the following 20 invention, include such substances as kieselguhr, variation: no talc was added to the polymeriza abestine, infusorlal earth, whiting, calcium sili tion reaction mixture. After the polymerization cate, magnesium carbonate, Kalite, lithophone, reaction was completed, it was noted that the in titanium pigment, zinc oxide, Zinc sul?de, terpolymer particles formed agglomerated into a organic toners and various waxes such as car large bulky mass, quite di?'erent from Example I. nauba, montan and rubber wax. These are the The solid polymer, after thorough water washing preferred species to be added severally or in and drying was found to have a molecular weight admixture in a pulverant comminuted form to of 80,000. This molecular weight was satisfac the reaction mixture prior to the commencement tory, and the solid polymer was suitable for com the interpolynierization reaction, since they pounding and curing to give a vulcanizate pos 30 of impart highly advantageous and desirable The sessing desirable physical characteristics. physical properties -to the vulcanizate. Since tendency of the interpolymer material, however, some of the materials enumerated above to coalesce or agglomerate after the completion. particularly the waxes are soluble in the alkyl of the polymerization reaction and in the washing halides, they may be incorporated in the form steps was highly undesirable, since the coalesced of a solution or supension and used as such in material was di?icult to handle and was not suit distributing the inert materials into the inter able ior plant operations such as hot air drying polymerization reaction mixture. and mechanical working on mill rolls. Example III 40 A similar mixture to that in Example I was pre pared, and to it was added approximately 10 parts by weight of the weight of the ole?nic material of bentonite. The polymerization was then con ducted, as in Example I. and an excellent poly mer well filled with the bentonite was obtained. The polymer showed only a minor tendency to agglomerate while in the cold liquid; coalesced only slightly during the warming up; and formed an excellent slurry in water at room temperature. ' The small amount of coalescence which occurred during the warming up was readily overcome, These anticoalescing materials may, in some instances, remain in the polymer through subsequent compounding, molding, and curing operations to serve as ?lters and colorants. Alternatively some of them may be more or less completely washed out by kneading the polymer in water in equipment such as the Werner and P?eiderer kneader. Relatively short time , oi.’ kneading in water will remove nine-tenths or more of the aqueous colloids and substantially all can be washed out by a reasonable length of time of kneading. In this respect, these materials are sharply different from other types of pigments. such as the reinforcing pigments, which cannot be washed out but become an integral part or the merely by vigorous stirring, since, in water, the polymer mass. bentonite swells up and disperses the polymer These examples‘ and the practicing of this very effectively in the water. invention show that the broad class of inert Example IV pulverant, comminuted, inert materials-such as talc,‘ inorganic pigments, clays, organic colloids, A similar mixture to that in Example I was etc.—will function to control and reduce the prepared, and to it was added approximately 2 parts by weight on the ole?nic mixture of ?nely 60 coalescing tendency of the slurry of interpolymer in the reaction medium as anticoalescing agents powdered gelatine. Gelatine as an amino acid is, at room temperature, strongly reactive with and serve as internal inert extenders when added aluminum chloride; but at polymerization tem to the interpolymers in the process of their for peratures below about -40° C. the material is mation in order to decrease the extent oi’ wholly inert and non-reactive. Nevertheless the 65 agglomeration, and to reduce the tendency of the particles serve as polymerization nuclei, and as interpolymer to adhere to metal and to coalesce a dispersing and de?occulating agent for the par in the intermediate drying and processing ticles of polymer; and, when the material was operations. ' brought up to room temperature in water, the Thus the invention consists of the steps, in gelatine substance swelled very rapidly and yield 70 combination, of adding to the interpolymerization ed a very thorough dispersion of the polymer. mixture of ole?nic or ole?nic-polyole?nic mate These examples are representative of three rials at low temperatures an inert anticoalescing groups of addition agents according to the inven and ?ller material, polymerizing the ole?ns in tion. Example I shows an inert powder; talc, the presence of anticoalescing material and. then which is representative oi.’ a considerable number 76 2 2,403,966 7 slurrying the solid polymer in water by the aid of the anticoalescing material. perature, separating the polymer in dispersed from from the polymerization mixture, slurrying the polymer in water, and maintaining the poly mer in dispersed form after polymerization by the action of the de?occulating agent. While there are above disclosed but a limited number of embodiments of the invention, it is possible to provide still other embodiments With out departing from the inventive concept here disclosed; and it is therefore desired that only 5. A polymerization process comprising the steps in combination of mixing a major propor such limitations be imposed upon the appended tion of isobutylene with a minor proportion of claims as are stated therein or required by the a diole?n having 4 to 12 carbon atoms, inclue 10 prior art. sive, cooling the mixture to a temperature with The invention claimed is: in the range of —20° 0. to —160° 0., adding to 1. In a polymerization process in which a the mixture an inert de?occulating agent, poly major quantity of an isoole?n of 4 to 8 carbon . merizing the mixture by the addition of a Friedel~ atoms is polymerized with a minor quantity of Crafts catalyst dissolved in a non-complex-form a diole?n of 4 to 12 carbon atoms at a tempera 15 ing solvent which is liquid at the polymerization ture of from —'-20° to —160° 0.. bymeans of a temperature, separating the polymer in dispersed solution of a Friedel-Crafts catalyst dissolved in form from the polymerization mixture, slurrying an alkyl halide which is liquid at polymerization temperatures, the step of conducting the poly merization in the presence of an inert de?occu lating agent, then separating the polymer in a the polymer in water, and maintaining the poly mer in dispersed form after polymerization by 20 the action of the de?occulating agent. 6. A polymerization process comprising the steps in combination of mixing a major pro portion of isobutylene and a minor proportion it in a dispersed form after polymerization by of butadiene, cooling the mixture to a tempera the action of the de?occulating agent. 25 ture within the range of —20° C, to —160° 0., 2. A polymerization process comprising the adding to the mixture an inert de?occulating steps in combination of mixing a major propor agent, polymerizing the mixture by the addition tion of an isoole?n having 4 to 8 carbon atoms, of a Friedel-Crafts catalyst dissolved in a non inclusive. with a minor proportion of a diole?n complex-forming solvent which is liquid at the dispersed form from the polymerization mixture, slurrying the polymer in water, and maintaining - having 4 to 12 carbon atoms, inclusive, cooling 30 polymerization temperature, separating the poly the mixture to a temperature within the range mer in dispersed form from the polymerization of --20° 0. to —160° 0., adding to the mixture an mixture, slurrying the polymer in water, and inert de?occulating agent comprising bentonite, maintaining the polymer in dispersed form after polymerizing the mixture by the addition of a polymerization by the action of the de?occulating Friedel-Crafts catalyst dissolved in an alkyl 35 agent. halide solvent which is liquid at the polymeriza 7. A polymerization process comprising the tion temperature, separating the polymer in steps in combination of mixing a major propor dispersed form from the polymerization mixture, tion of isobutylene and a minor proportion of slurrying the polymer in water, and maintaining the polymer in dispersed form after polymeriza 40 'isoprene, cooling the mixture to a temperature within the range of —20° 0. to —160° 0., add tion by the action of the de?occulating agent. ing to the mixture an inert de?occulating agent. 3. A polymerization process comprising the polymerizing the mixture by the addition of a steps in combination of mixing a major propor. Friedel-Crafts catalyst dissolved in a non-com tion of an isoole?n having 4 to 8 carbon atoms, inclusive, with a minor proportion of a diole?n 45 plex-forming solvent which is liquid at the poly merization temperature, separating the polymer having 4 to 12 carbon atoms, inclusive, cooling in dispersed form from the polymerization mix the mixture to a temperature within the range. ture, slurrying the polymer in water, and main of -20° C. to —160° 0., adding to the mixture an taining the polymer in dispersed form after poly inert de?occulating agent, polymerizing the mix merization by the action of the de?occulating ture by the addition of a Friedel-Crafts catalyst agent. dissolved in an alkyl halide solvent which is 8. A polymerization process comprising the liquid at the polymerization temperature, sepa steps in combination of mixing a major propor rating the polymer in dispersed form from the tion of isobutylene and a minor proportion of polymerization mixture adding the polymer to dimethyl butadiene, cooling the mixture to a water, and maintaining the polymer in dispersed temperature within the range of —-20° C. to —160° form after polymerization by the action of the 0., adding to the mixture an inert de?occulating de?occulating agent. agent, polymerizing the mixture by the addition 4. A polymerization process comprising the of a FriedeI-Crafts catalyst dissolved in a non steps in combination of mixing a major propor complex-forming solvent which is liquid at the tion of an isoole?n having 4 to 8 carbon atoms, 60 inclusive, with a minor proportion of a diole?n having 4 to 12 carbon atoms, inclusive, cooling the mixture to a temperature within the range of —20" 0. to —160° 0., adding to the mixture an inert de?occulating agent comprising gela tine, polymerizing the mixture by the addition of a Friedel-Crafts catalyst dissolved in an alkyl halide which is liquid at the polymerization tem polymerization temperature, separating the poly_ mer indispersed form from the polymerization mixture, slurrying the polymer in water, and maintaining the polymer in dispersed form after polymerization by the action of the de?occulating agent. >' "JOHN R. BROWN, JR. IRVING E. HGH'I‘BOWN.