MXPA00002353A - Gas phase polymerization of vinylpolybutadiene - Google Patents

Abstract

A process for the preparation of a 1,2-vinyl polybutadiene with an adjustable amount of vinyl linkages in the microstructure of the polymer which comprises polymerizing 1,3-butadiene in a gas phase reactor under polymerization conditions using an inert gas in the presence of a catalyst comprising:(a) a cobalt compound;(b) a compound selected from the group consisting of a phosphine, a xanthogen, a thiocyanide, a carbon disulfide, and mixtures thereof;and (c) an organoaluminum compound, and optionally a modifier (d) can be included in the catalyst composition. There is also provided a novel resin particle prepared by the process.

Description

POLYMERIZATION OF VINYLPOLIBUTADIENE IN GAS PHASE FIELD OF THE INVENTION The present invention relates to the production of a polybutadiene with a vinyl microstructure. More particularly, the invention relates to a 1,2-vinyl polybutadiene having an adjustable vinyl content that falls within a range from about 1% to about 99.9% vinyl in the polymer microstructure, said polymer being produced in a polymerization process in gas phase. BACKGROUND OF THE INVENTION To date, 1,2-vinyl-polybutadiene has only been commercially available in solution, paste or emulsion processes, such as, for example, the processes disclosed in US Pat. Nos. 3,498,963; 3,778,424; 4,182,813; and 5,548,045. Numerous problems associated with the production of vinyl polybutadiene were observed in these processes: the products are too crystalline or conversely have excessive rubber-like properties; they tend to be adversely affected by impurities, especially moisture, air, and water; require difficult polymerization conditions (eg, relatively low temperature and / or multiple reactors) for efficient commercial production; incompatibility of solvent medium with components / catalyst combinations; difficulties in controlling molecular weight; contamination with low molecular weight polymers; inability to incorporate a desirable amount of vinyl into the polymer; they require a large amount of catalyst due to a low catalyst productivity; low yield of desired product; etc. In addition, these processes require a lot of labor and a lot of energy, require several steps of washing and separation and removal of solvents, and present problems for the environment. All this increases the cost of the product and limits its use and availability due to its cost in the market. Finally, the vinyl polybutadiene products produced in these processes are recovered in bales, or in the form of bullet type, in such a way that before an end user can combine these products with other formulation components, the polybutadiene products containing vinyl themselves they must first be cut, ground and / or pulverized before a significant subsequent dispersion and distribution in an end-user formulation or processing can occur. It would be beneficial to carry out a polymerization of vinyl polybutadienes in a gas phase reactor, since a gas phase polymerization would be profitable, economical, and inherently safer insofar as the need to handle and recover large quantities of gas is eliminated. solvent while providing an operation in a process with low pressure. However, taking into account all of the processing difficulties mentioned above associated with the production of vinyl polybutadiene in non-gas phase processes, it would be unlikely to be expected that the production of vinyl polybutadienes in a gas phase process would be possible, and much less easy. On the contrary, one could expect some or many of the same problems associated with non-gas phase processes, as well as problems attributable to a gas phase operation. Nor is it expected that the product was easily formed into granules and / or can flow, have a regular, relatively homogeneous vinyl microstructure distributed throughout the polymer. Surprisingly, the present invention offers a process and a vinyl polybutadiene product of this type. SUMMARY OF THE INVENTION Accordingly, there is provided a process for the preparation of vinyl polybutadiene comprising the polymerization of 1,3-butadiene in a gas phase reactor under polymerization conditions using an inert gas in the presence of a catalyst comprising: ( a) a cobalt compound; (b) a compound selected from the group consisting of a phosphine compound, a xanthogen compound, a thioisocyanide, a carbon disulfide compound, or a mixture thereof; and (c) an organoaluminum compound; provided that when a cobalt phosphine is used, an additional phosphine compound is not required. The catalyst composition may further contain (d) a modifier. In addition, a free-flowing, granular-shaped resin particle is provided, consisting of a core and a shell wherein the core contains a mixture of particulate inert material and vinyl polybutadiene where the core mixture is essentially (more than 50%) of vinyl polybutadiene and the shell contains a mixture of inert particulate material where the shell mixture consists essentially of inert particulate material (more than 50%). DETAILED DESCRIPTION OF THE INVENTION Polymer. The vinylpolybutadiene produced by the gas phase process of the present invention can be a syndiotactic 1,2 (vinyl) -butobutadiene, an isotactic 1,2 (vinyl) -polybutadiene, an atactic 1,2 (vinyl) -polybutadiene, or a mixture thereof, with a polymer being preferred which is predominantly syndiotactic 1,2-vinyl-polybutadiene. The vinyl content can be adjusted within a range of about 1% to 99.9% vinyl in the polymer microstructure. For some end uses it is desirable to have a lower vinyl content (e.g., approximately % to about 70% vinyl in the polymer microstructure) together with cis and trans bonds in the microstructure. Likewise, a polymer having this vinyl content of 30% to 70% does not have tacticity or has a lower tacticity compared to a polymer whose vinyl content is higher (for example from about 80% to about 99.1%) . The vinyl polybutadiene obtained from the process of the present invention can be used in films, fibers, and molded articles. It can be used alone or in mixture with other natural or synthetic rubbers. In addition to natural rubber, synthetic rubbers combinable with the vinyl polybutadienes of the present invention can include, for example, styrene-butadiene rubber, butadiene rubber, isoprene rubber, nitrile rubber, chloroprene rubber, ethylene-alpha-olefin rubber, rubber of ethylene-alpha-olefinadiene, 1,2-polybutadiene, 1,4-polybutadiene, and the like. Preferably, the vinyl polybutadienes of the invention are used in combination with synthetic rubbers produced by processes in gas phase. If necessary, it can be spread with a process oil, and then mixed with conventional composition agents for vulcanized rubbers, such as filler, vulcanizing agent, accelerator, tackifier, and the like in order to obtain a composition of rubber. The thermoplastic polybutadiene of the present invention is used to make bags, packages, tubes, hoses, shoe soles, tires, and other rubber products. As for vulcanization, it is used in rubber applications where mechanical properties and resistance to abrasion are required, for example. In the vinyl polybutadiene obtained in the present invention, the molecular weight can vary over a wide range but the molecular weight the reduced average number is preferably from 5,000 to 1,000,000, more preferably from 10,000 to 800,000. The Mooney viscosity (MLi + 4 at 100 ° C) of the vinyl polybutadiene obtained in the present invention is preferably from about 20 to 150, more preferably from about 30 to 80. Polybutadiene (BR) with high vinyl content ( 1,2) (or HVBR) having from 85 to 99% of vinyl groups, or with a medium vinyl content (or MVBR) having from 30 to 84% of vinyl groups can be prepared by the process of present invention. Polybutadienes with an average content of vinyl tend to have an elastic, thermosetting, or amorphous appearance and behave like an emulsion-polymerized styrene-butadiene rubber (SBR). They can be used in a triple mixture of MVBR / SBR / cis-BR. HVBR, on the other hand, is thermoplastic or crystalline and can be used in mixtures and thermoplastic applications.

In accordance with the process of the present invention, a novel core-shell resin particle composed of a vinyl polybutadiene particle and an inert particulate material is produced. The core-shell type resin particle is formed of a mixture of vinyl polybutadiene and inert particulate material wherein the mixture in the core contains a majority of polymer and the mixture in the shell contains a majority of inert particulate material. In a preferred embodiment, a resin particle is produced comprising an outer shell having a mixture of an inert particulate material and a vinyl polybutadiene polymer said inert particulate material is present in said outer shell in an amount greater than 75% in. weight based on the weight of said outer shell, and an inner core having a mixture of said vinyl polybutadiene polymer and said inert particulate material, said vinyl polybutadiene polymer is present in said core in an amount greater than 90% by weight , based on the weight of said internal core. The particle has a cobalt residue that ranges from about 2 ppm to about 200 ppm, preferably from about 2 ppm to about 100 ppm, and more preferably from about 2 ppm to about 30 ppm. The particle may also have a phosphorus residue that is within a range of about 0.5 to 50 ppm, preferably 0.5 to 20 ppm; and a sulfide residue that is within a range of about 0.1 to 250 ppm, preferably 0.1 to 150 ppm. More preferably, the resin particle is produced by fluidized bed polymerization at temperatures that are at the softening or tackifying temperature of said vinyl polybutadiene or above said softening or tackiness temperature. The vinylbutadiene polymer produced by the process of the present invention is in the form of granules, free flowing, and / or flowable. By fluid we understand that the polymer produced by the process can be transported (for example by physical or mechanical means) using means and / or conventional or standard transport processes, for example, dense phase transportation. Monomer The monomer used in the process of the present invention is 1,3-butadiene. Catalyst. The catalyst composition of the present invention comprises: (a) a cobalt compound; (b) a phosphine, a xanthogen compound, a thioisocyanide, a carbon disulfide compound, or a mixture thereof; and (c) an organoaluminum compound. A modifier (d) can be further included in the catalyst composition. A cobalt-phosphine complex, a single component, can be employed in place of separate individual components (a) and phosphine compound of (b). Supported catalyst systems (eg, in silica, alumina, and / or carbon black) can be employed as well as unsupported (liquid or soluble feed). Cobalt compound The cobalt compound that can be used in the present invention can have an apparent valence from zero to maximum valence, with a preferred oxidation state of (II) or (III). As such, the cobalt compound is, for example, a cobalt salt of an inorganic or organic acid, a cobalt complex of one of the salts and an electron donor as a ligand. Typically, the cobalt salts of an inorganic acid are cobalt halides (e.g., Cl, Br and I), cobalt sulfate, cobalt nitrate, cobalt carbonate, cobalt phosphate, cobalt sulfide, cobalt hydroxide, cyanide. of cobalt, cobalt cyanate, cobalt thiocyanide, and cobalt naphthenate. Cobalt salts of organic acids may include, for example, cobalt octenoate, cobalt acetate, cobalt oxalate, cobalt valerate, cobalt carboxylate, cobalt stearate, cobalt versatate, cobalt benzoate, cobalt butanoate, hexanoate cobalt, cobalt heptanoate, cobalt salts of octanoic acids (such as 2-ethylhexanoic acid), cobalt decanoate; cobalt salts of higher fatty acids (stearic, oleic, etc.), cobalt salts of benzoic acids substituted by alkyl, aralkyl and aryl such as for example xylylic acid, ethylbenzoic acid and the like; cobalt naphthoate; and cobalt salts of naphthoic acids substituted by alkyl, aralkyl, or aryl, and the like, the electron donor as a ligand for complex formation includes phosphine compounds; phosphite compounds; pyridine, amines; dipyridyl compounds; phenanthroline; carbonyl; isonitrile; olefins; cyclodiene compounds such as 1,5-cyclooctadiene and cyclopentadiene; vinyl compounds; cyclopentadienyl compounds; pi-allyl compounds; 1,3-diketones, for example acetylacetone and acetoacetic acid, etc. Complex cobalt compounds such as, for example, cobalt bis-acetylacetonate, cobalt bis-acetoacetate, cobalt bis-diethylmalonate, cobalt bis-dimethylglyoxy a, dicyclopentadienyl cobalt, bis-1,5-cyclooctadiencobalt, cyclopentadienylcobalt, bis-1, 5- cyclooctadiencobalt, cyclopentadienyl cobalt cyclooctatethylene, cobalt tris-acetylacetonate, cobalt tris-acetoacetonate, cyclopentadienyl cobalt dicarbonyl, tri-pi-allyl cobalt, cyclohexadiencobalt dicarbonyl, dicobalt octacarbonyl, diene-tetracobalt tetracarbonyl, butadiene-cobalt hexacarbonyl and the like may be used in the catalyst system of the process of the present invention. Preferably these cobalt complexes having organic phosphine compounds as ligands are, for example, cobalt-phosphine complexes, CoX2 (PRR5R6) 2 wherein X represents a halogen atom, CN, or -SCN; and wherein each of R, R5 and R6 are the same or different and represent a C? -C8 alkyl group, a C6-C? 2 aryl group, or a hydrogen atom. Such complexes may include, for example, bis (triphenylphosphine) cobalt dibromide, bis (triphenylphosphine) cobalt dichloride, bis (tri-m-methylphenylphosphine) cobalt dibromide, bis (tri-m-methylphenylphosphine) cobalt dichloride, bis (tri) -p-methylphenylphosphine) cobalt dibromide, bis (tri-p-methylphenylphosphine) cobalt dichloride, bis (tri-p-methoxyphenylphosphine) cobalt dibromide, bis (tri-p-ethoxyphenylphosphine) cobalt dichloride, bis (dicyclohexylphenylphosphine) dibirroomuurroo of cobalt, bis (dicyclohexylphenylphosphine) cobalt dichloride, bis (tri-m-dimethylphenylphosphine) cobalt dibromide, bis (3,? -dimethyl-4-methoxyphenylphosphine) cobalt bromide, bis (3,5-dimethyl-4-methoxyphenylphosphine)) cobalt chloride and the like. In the present invention, the cobalt compound is employed in an amount of about 0.001 to 1 millimole, preferably about 0.01 to 0.5 millimole in terms of cobalt atoms per mole of 1,3-butadiene. Phosphine If it is not part of the cobalt (a) complex, the phosphine ligand can be added separately to the catalyst system. Typically, a tertiary phosphine compound is employed in order to control the 1,2-microstructure configuration of vinyl polybutadiene and the stereoregularity of the 1,2-configuration of the polymer. Preferably, tertiary phosphines, which have the general formula: PR4R5R6, where P is phosphorus; and R 4, R 5, R 6 are an alkyl, aryl, or hydrogen atom are used. The preferable alkyl group in the formula is a straight chain, branched chain, or cyclic alkyl group having from 1 to 8 carbon atoms, such as, for example, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, hexyl groups , octyl, and cyclohexyl. As the aryl group, phenyl and tolyl groups are preferred. These include, for example, aromatic phosphines such as tri (3-methylphenyl) -phosphine, tri (3-ethylphenyl) -phosphine, tri (4-methylphenol) phosphine, tri (3,5-dimethylphenyl) phosphine, tri (3, 4-diraethylphenyl) phosphine, tri (3-isopropylphenyl) phosphine, tri (3-tert-butylphenyl) phosphine, tri (3,5-dimethylphenyl) phosphine, tri (3-methyl-5-ethylphenyl) -phosphine, tri (3-phenylphenyl) ) phosphine, tri (3, 4, 5-trimethyl-phenyl) phosphine, tri (4-methoxy-3,5-dimethylphenyl) phosphine, tri (4-ethoxy-3,5-diethylphenyl) phosphine, tri (4-butoxy) -3,5-dibutylphenyl) -phosphine, tri (4-methoxyphenyl) phosphine, tricyclohexylphosphine, dicyclohexylphenylphosphine, dicyclohexylbenzylphosphine, tribenzylphenylphosphine, tri (4-methylphenyl) phosphine, 1,2-diphenylphosphinoethane, 1,3-diphenylphosphinopropane, 1,4- diphenylphosphinobutane, tri (4-ethylphenyl) phosphine and the like, and aliphatic phosphines such as triethylphosphine, tributylphosphine and the like, among these elements, especially triphenylphosphine, tri (3-ethylphenyl) phosphine, tri (4-methoxy), 3, 5-dimethylphenyl) -phosphine, tri (4-methoxyphenyl) phosphine, tri (dicyclohexylphenyl) -phosphine, tricyclohexylphosphine, tribenzylphosphine, tributylphosphine, dicyclohexylbenzylphosphine and tri (4-methylphenyl) phosphine. The phosphine is used in the catalyst in an amount that is within a range of about 0.01-10 moles per mole of cobalt compound, preferably about 0.05-5 moles per mole of cobalt compound. Xanthogens, thioisocyanides, and carbon disulfide. Instead of a phosphine compound, or in addition to a phosphine compound, a sulfur derivative can be added. The use of a sulfur derivative in the process of the present invention allows adjustment of the vinyl content from 50% to 99.9%. Such sulfur derivatives can include carbon disulfide, a xanthogen compound, a thioisocyanide compound, or a mixture thereof can be used as catalyst component (b). Suitable xanthogen compounds are presented, for example, in U.S. Patent No. 4,742,137. Specific examples of xanthogen compounds include diethylxanthogen sulfide, dimethylxanthogen sulfide, phenylxanthogen sulfide, tolylxanthogen sulfide, and mixtures thereof. Suitable thioisocyanide compounds are presented, for example, in US Pat. 5,548,045. Specific examples of the thioisocyanide compound include phenyl thioisocyanide, tolyl thioisocyanide, and mixtures thereof. In relation to the cobalt compound, these compounds (xanthogen, thioisocyanide, CS2, etc.) are used within the same range as that reported for phosphine, above, that is, in amounts that are within a range of approximately 0.5 to 10 moles per mole of cobalt compound (a). Organoalurainium. The organoaluminum compound used as component (c) is represented by one of the following three formulas: (I) A1R3 (II) Ml? NXs-m (III) AlRn2 (OR3) 3-n where each R, R1, R2 , R3 is the same or different and is a straight or branched chain alkyl group having from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, an aryl group (for example phenyl or tolyl), or a hydrogen; X is halogen (F; Cl, Br, and I, with Cl being preferred); m is 0, 1, 1.5 or 2; and n is 1 or 2. The organoaluminum compounds include alkylaluminums, halogenated alkylaluminum compounds, as well as alkylaluminum alkoxides, alkylaluminum hydroxides, and alkylaluminium hydrides. When organoaluminum compounds of the formulas (I) - (III) are used as the catalyst component (c) in the process of the invention, water is also used. The amount of water added together with the component (c) for organoaluminum compounds of the formulas (I) - (III) is within a range of 0.25 to 1.5 moles per mole of the organoaluminum compound. The organoaluminum can also be: where in (IV) and (V) each R is a hydrocarbon group, preferably R represent the same hydrocarbon groups, such as for example methyl, ethyl, propyl, butyl; m represents an integer from 2 to 100. Specific examples of the aluminoxane include methylaluminoxane, ethylaluminoxane, propylaluminoxane, butylaluminoxane, modified methylaluminoxane, and the like. The organoaluminum compound is used for the purpose of providing an Al / C atomic ratio between the aluminum atoms in (c) and the cobalt atoms in (a) of 4-107, more preferably 10-106. The molar ratio between the cobalt compound and the organoaluminum compound is usually within the range of 1/1 to 1 / 1,000, preferably 1/5 to 1/100. Modifier An additive can additionally be added to control the 1.2 consideration of the microstructure of the vinyl polybutadiene obtained and also to change the crystallinity of the polymer. These modifiers (d) may include, for example, amides, aldehydes (in accordance with that indicated in US Patents Nos. 5,011,896 and 5,278,263) or tertiary amines (in accordance with that indicated in US Patents Nos. 3,778,424 and 4,258,160) . Among these, triethylamine, tributylamine, and N, N-dibutylformamide (DBF) are preferred. When the modifier such as DBF is used, it is added to the reaction mixture in the gas phase reactor, either in pure form, as a solution, or through a previous contact with a catalyst component or with all of the catalyst components, in any order. The amount of the modifier used in the catalyst is 0.05 to 10 moles per mole of cobalt compound, preferably 2 to 7 moles per mole of cobalt compounds.

Gel suppressor Gel suppressors such as for example amines, ethers and the like can be used if desired. Typical gel suppressors as well as their use are described in U.S. Patent No. 5,652,304. Preparation of catalyst. The catalyst used in the present invention is prepared by the addition of individual components in any desired order and its mixture preferably in a hydrocarbon or halogenated hydrocarbon solvent or the components are added separately. The preparation can be carried out before the catalyst comes into contact with 1,3-butadiene, or it can be carried out by mixing the components in the presence of 1,3-butadiene in the reactor. The solvent is an inert organic solvent and includes aromatic hydrocarbon solvents such as benzene, toluene, xylene, methylene chloride, eumeno, and the like; aliphatic hydrocarbon solvents such as pentane, hexane, butane and the like; solvents of alicyclic hydrocarbons such as methylcyclopentane, cyclohexane, and the like; halogenated hydrocarbon solvents such as methylene chloride, chloroform, carbon tetrachloride, 1,2-dichloroethane, trichlorethylene, perchlorethylene, chlorobenzene, bromobenzene, chlorotoluene, and the like; and mixtures thereof. The catalyst can be supported by mixing the support material, the metal component, cocatalyst, optional promoter in any order in an inert solvent or diluent. When the metal component is supported, typical supports may include, for example, silica, carbon black, porous crosslinked polystyrene, crosslinked porous polypropylene, alumina or magnesium chloride support materials. Among these support materials, carbon black, silica, and blends of carbon black and silica are preferred. A typical silica or alumina support is a porous, solid, particulate material essentially inert to the polymerization. It is used as a dry powder having an average particle size of about 10 to about 250 microns and preferably about 30 to about 100 microns; a surface area of at least 200 square meters per gram and preferably at least about 250 square meters per gram; and a pore size of at least about 100 Angstroms, preferably at least about 200 Angstroms. Generally, the amount of support that is used is the amount that will offer from about 0.1 to about 1.0 millimole of rare earth metal per gram of support. In a preferred embodiment, two types of carbon black are used as support. DARCO G-60 is used (pH of water extract = 5) as dry powder having a surface area of 505 square meters per gram, average particle size of 100 microns, and porosity of 1.0 to 1.5 cubic centimeters per gram. NORIT A (pH of water extract = 9-11) used as dry powder has a surface area of 720 square meters per gram, an average particle size of 45 to 80 microns. These stands are available both at Aldrich. In general, the metal component may be impregnated in a support by well-known means such as, for example, by dissolving the metal compound in a solvent or diluent such as hydrocarbon, chlorinated hydrocarbon, or ether (including aliphatic, cycloaliphatic or aromatics such as pentane, isopentane, hexane, cyclohexane, benzene, toluene, tetrahydrofuran, and methylene chloride) in the presence of the support material and then removing the solvent or diluent by evaporation such as under reduced pressure. Alternatively, the metal component can be dissolved in a solvent or diluent such as a hydrocarbon or tetrahydrofuran and spray dried in order to generate a well-formed catalyst precursor that has little silica or no silica or other solid inorganic content , if desired. A preferred method for preparing one of the catalyst components of this invention includes impregnation of a silica support, a carbon black support, or a mixed support of the two with a cobalt-containing compound. The amount of metal impregnated in the support can be located within a range between 0.1 and 1.0 mmol / g of catalyst. An organic alkylaluminum compound can be added before, during or after the impregnation step, either in a hydrocarbon such as those mentioned above or in an oxygenated solvent such as THF. The catalyst can be isolated as a dry solid or used as a paste in a diluent. A more preferred process for making the catalysts of the present invention by treating a silica support, a carbon black support, or a mixture with the cobalt compound in a suitable solvent followed by solvent removal. The catalyst can also be prepared without support by simply contacting the metal with the alkylaluminum compound to form a solution or paste that is fed directly to the reactor. The ratio between aluminum and metal in the catalyst preparation step can vary between 0.5 and 1000. The polymerization metal can be used without aluminum treatment when the aluminum alkyl is fed separately to the reactor together with the other additives and modifiers. In order to avoid deactivation of the catalyst, it is desirable to take measures to avoid or minimize the incorporation of deactivation compounds such as oxygen, water, carbon dioxide, carbon monoxide and the like in the catalyst preparation and polymerization system. Accordingly, it is preferred to carry out the polymerization and prepare the catalyst under an inert atmosphere (nitrogen, argon, isopentane, ethane, butane, etc.). Processes and polymerization conditions. The present invention is not limited to a specific type of polymerization reaction in stirred or fluidized gas phase and can be carried out in a single reactor or in several reactors (two or more reactors connected in series preferably). In addition to conventional well-known gas phase polymerization processes, "condensed mode" can also be used, including what is known as "induced condensate mode", and "liquid monomer" operation of a gas phase polymerization reactor . A conventional fluidized bed process for producing resin is practiced by passing a gaseous stream containing one or more monomers, usually a monomer, continuously through a fluidized bed reactor under reactive conditions in the presence of the catalyst described above. The product is removed from the reactor. A gaseous stream of unreacted monomer is withdrawn from the reactor continuously and recycled to the reactor together with compensating monomer added to the recycle stream. Conventional gas phase polymerizations are presented, for example in US Pat. Nos. 3,922,322; 4,035,560; and 4,994,534. Optionally, and preferably, a conventional polymerization of the present invention is carried out in the presence of one or more inert particulate materials in accordance with that described in US Patent No. 4,994,534. Condensed mode polymerizations are presented in U.S. Patent Nos. 4,543,399; 4,588,790; 4,994,534; 5,352,749; and 5,462,999. Condensate mode processes are used to achieve higher cooling capacities and, consequently, higher reactor productivity. In these polymerizations, a recycling stream, or part thereof, can be cooled to a temperature below the dew point in a fluidized bed polymerization process, resulting in the condensation of all or part of the polymerization. of the recycling stream. The recycle stream is returned to the reactor. The point of waste of the recycling stream can be increased by raising the operating pressure of the reaction / recycling system and / or by increasing the percentage of condensable fluids and decreasing the percentage of non-condensable gases in the flow of recycling. The condensable fluid may be inert to the catalyst, reagents and polymer product produced; it can also include monomers and comonomers. The condensation fluid can be introduced into the reaction / recycling system at any point in the system. Condensable fluids include saturated or unsaturated hydrocarbons. In addition to condensable fluids from the polymerization process itself, other condensable, inert fluids for polymerization can be introduced in order to "induce" an operation in condensation mode. Examples of suitable condensable fluids may be selected from liquid saturated hydrocarbons containing from 2 to 8 carbon atoms (e.g., ethane, propane, n-butane, isobutane, n-pentane, isopentane, neopentane, n-hexane, isohexane, and others. hydrocarbons Ce saturated, n-heptane, n-octane and other hydrocarbons C and Ce saturated, and mixtures thereof). Preferred condensable fluids for use in the process of the invention include n-butane, isobutane, isopentane, and mixtures thereof. Condensable fluids may also include polymerizable, condensable comonomers such as olefins, alpha-olefins, diolefins, diolefins containing at least one alpha-olefin, and mixtures thereof. In the condensation medium, it is desirable that the liquid entering the fluidized bed be dispersed and vaporized rapidly. One mode of polymerization of liquid monomers is presented in U.S. Patent No. 5,453,471; US Patent Application Serial No. 510,375; PCT 95/09826 (US) and PCT 95/09827 (US). When operating in the liquid monomer mode, the liquid may be present in the entire polymer bed provided that the liquid monomer present in the bed is adsorbed on the solid particulate matter present in the bed or absorbed within the bed. of said solid particulate matter present in the bed, such as over / within produced polymers or fluidization aids, which are also known as inert particulate materials (e.g., carbon black, silica, clay, talc, and mixtures thereof) present in the bed, insofar as there is no substantial amount of free liquid monomer present. The liquid mode makes it possible to produce polymers in a gas phase reactor by employing monomers having condensation temperatures much higher than the temperatures at which conventional polyolefins are produced. In general, the liquid monomer process is carried out in a stirred bed or gas fluidized bed reaction vessel having a polymerization zone containing a growth bed of polymer particles. The process comprises the continuous introduction of a stream of one or more monomers and optionally one or more inert gases in the polymerization zone optionally in the presence of one or more inert particulate materials; the continuous or intermittent introduction of a reactive nickel polymerization catalyst in accordance with that described herein in the polymerization zone; the continuous or intermittent withdrawal of polymer product from the polymerization zone; and the continuous removal of unreacted gases from the area; compressing and cooling the gases while maintaining the temperature within the zone below the dew point of at least one monomer present in the zone. If there is only one monomer present in the gas-liquid stream as in the process of the present invention, there is also optionally and preferably at least one inert gas. Typically, the temperature within the zone and the velocity of gases passing through the zone are such that essentially no liquid is present in the polymerization zone that is not adsorbed on the solid particulate matter or absorbed within the material in solid particles. The use of fluidization aids is preferred in the liquid monomer process and in the process of the present invention. Taking into account the dew points or condensation temperatures of the diene employed in the gas phase polymerization process of the present invention, the liquid monomer mode is the preferred mode of polymerization.

In general, elastomers such as those of the present invention are produced in a fluidized gas phase reactor at the softening or tackiness temperature or above said temperature of the polymer product optionally and preferably in the presence of a particulate material. Inert selected within the group consisting of carbon black, silica, clay, talc, and mixtures thereof. Of the inert particulate materials, carbon black, silica and a mixture thereof, especially carbon black, are preferred. The inert particulate material is employed in the gas phase polymerization within a range which is between about 0.3 and about 80% by weight, preferably from about 5 to about 75% by weight, especially from 5 to 50% by weight. weight based on the weight of the final elastomeric polymer product. However, when preparing high syndactic high vinyl BR, it is not always necessary to use carbon black or other inert particle material since the polymer is thermoplastic and not elastomeric. Preferably the reactor system is passivated with the organoaluminum cocatalyst compound before starting the polymerization. Optionally, and preferably, the inert particulate material and / or the seed bed are also passivated with the organoaluminum compound.

In general, all the above modes of polymerization are carried out in a gas phase fluidized bed constituted or containing a polymer "seed bed" that is the same as or different from the polymer product being produced. The bed preferably consists of the same granular resin that must be produced in the reactor. Thus, during the course of the polymerization, the bed comprises polymer particles formed, particles of polymer in growth, and catalyst particles fluidized by the polymerization and gaseous modification components introduced at a flow rate or rate sufficient to cause the particles separate and act as fluid. The fluidizing gas consists of the initial feed, the compensating feed, and the recycle gas, i.e., monomer, and if desired, modifiers and / or an inert carrier gas (eg, nitrogen, argon, or hydrocarbon). inert (for example, a C1-C20 alkane such as, for example, isopentane or butane), with nitrogen and / or butane being preferred). A typical recycling gas consists of the monomer, inert carrier gas (s), and optionally hydrogen, either alone or in combination. The process can be carried out in a lot or continuously, with the latter option being preferred. The essential parts of the reactor are the container, the bed, the gas distribution plate, the inlet and outlet piping, at least one compressor, at least one recycle gas cooler or heat exchanger, and a discharge system of product. In the container, above the bed, there is a zone of speed reduction, and in the bed a reaction zone. Both are located above the gas distribution plate. If desired, variations in the reactor can be introduced. One variation includes the claim of one or more recycle gas compressors upstream to downstream of the cooler and another variation includes the addition of a vent line from the top of the product discharge vessel (stirred tank product). ) back to the top of the reactor to improve the call level of the product discharge container. In general, the polymerization conditions in the gas phase reactor are such that the temperature is within a range of about 0 to 120 ° C, preferably about 40 100 ° C, especially about 35 to 80 ° C. The partial pressure will vary according to the polymerization temperature and can be within a range of approximately 1 to 125 psi. The condensation temperature of the monomer is well known and is -4.5 ° C at atmospheric pressure. In general, it is preferred to operate at a partial pressure slightly up to slightly below, (i.e., ± 10 psi) from the monomer dew point. For example, in the case of 1,3-butadiene, the partial pressure is within a range of about 10 to about 100 psi. The total reactor pressure is within a range of about 100 to about 500 psi. Typically, the process of this invention is operated to have a space-time yield ratio (STY) of about 1:10. That is, a residence time longer than that used for polymerisation of alpha olefins is generally required. The higher the space-time yield ratio, the faster the polymer product in the reactor occurs. When employed, the solution catalysts are fed to the reactor in accordance with U.S. Patent No. 5,317,036. In accordance with the process of the present invention, the vinyl content in the obtained polybutadiene can be easily controlled over a wide range, for example by controlling the polymerization temperature. Thus, for example, higher temperatures (for example 50 to 80 ° C) result in higher amounts of vinyl bonds in the polymer, while lower temperatures (eg, from 25 to 40 ° C) result in lower amounts of vinyl bonds incorporated in the final polymer. When the polymerization reaction has reached a desired stage or must be terminated, an alcohol or other catalyst terminator or deactivator such as ammonia or water is added to the reaction. A stabilization package comprising one or more of the following can also be added: an aging retarder, an antioxidant, an antiozonant, an ultraviolet ray absorber, etc. The vinyl polybutadiene is then purged with an inert gas, optionally and the inert gas and water, to remove the unreacted monomer that is recycled to the reactor in the gas phase. All references mentioned herein are incorporated by reference. The invention is illustrated in the following examples. All parts and percentages are by weight, unless otherwise specified. EXAMPLES Characterization of polymer product. In the examples, property measurements were made in accordance with the following methods: the weight of the polymer was used to determine the yield. The microstructure was determined by IR. The melting point was obtained by DSC. Estimates of molecular weights were obtained by measuring the reduced viscosity, but GPC data was also collected. The GPC data were obtained with a Waters® 590 instrument and with a differential refractometer ERMA®ERC-7510 at room temperature with Waters® Styragel and tetrahydrofuran columns or toluene as the mobile phase. Polystyrene standards were used for calibration in the molecular weight range from 162 to 1,800,000. The reduced viscosity (RV), or the reduced specific viscosity (RSV), or viscosity index, is a measure of the ability of a polymer to increase the viscosity of a solvent. It is the ratio between the specific viscosity of a solution and the concentration (c) of the solute. In a diluted polymer solution, c is usually expressed in grams of polymer per deciliter (di) of solution. The specific viscosity is obtained by comparing the retention time (t) required for a solution of known concentration to flow between two marks in a capillary tube with the retention time required by the solvent (to). The definition is as follows:? Sp = (t-t0) / t0? Red =? Sp / c the reduced viscosity is expressed in the unit of dl / g. In this application, RV is determined by the following procedure: 0.15 g of BR containing stabilized flow aid and 50 ml of toluene were added in a 100 ml bottle with cap. The mixture was stirred overnight at room temperature and separated first by centrifugation then by filtration through glass wool and finally by filtration through a "millipore" filter. The solution obtained in this way was added to a Cannon-Fenske® viscometer and the retention time was measured at a temperature of 30 ° C. Is calculated RV using the following equation: RV = [(t-to) / t0] / c The concentration c was determined by solvent evaporation from an aliquot of 25 mL of the solution and by weighing the polymer residue in a aluminum plate. The following examples employ five different systems of cobalt catalyst, namely (B) CoBr2 / PPh3) 2 (C) (1-methylallyl) (buta-1,3-diene) triphenylphosphine cobalt, (D) CoCl2 (pyridine) 4, and (E) Co (acac) 3 in combination with 3 eq. CS2 Co (acac) 3, CoBr2, CS2, PPh3 were purchased from Aldrich Chemical Company, CoCl2 was purchased from AlfaAesar and MAO was obtained (1.8 M in toluene) in Akzo Nobel and used without further purification. All solvents were dried by standard procedures and then distilled under a nitrogen atmosphere. Cobalt triphenylphosphine (1-methyl-allyl) (buta-1, 3-diene) was prepared according to G.Vitulli, L. Porri, A.L. Segre, J. Chem. Soc (A) 1971, 3246. C0Cl2 (pyridine) 4 was prepared by stirring C0Cl2 in distilled pyridine overnight. Preparation of CoCl2 (PPh3) 2 CoCl2 (4.3g) was dissolved in 30 ml of ethanol under an inert atmosphere of nitrogen at a slightly elevated temperature. Triphenylphosphine (20g) was placed in a second flask and mixed with 130 ml of distilled ethanol. To this stirred paste the CoCl2 solution was added slowly through a syringe. The mixture was stirred in a hot ary bath under nitrogen pressure for 15 minutes. The catalyst was transferred into an inert frit and washed first with ethyl acetate, then with ethanol and dried under high vacuum. Isolated yield: 19.7 g of C0CI2 (PPh3) 2. Preparation of Co Br2 (PPh3) 2 An analogous procedure was used to prepare CoBr2 (PPh3) 2 from 7.3 g of CoBr2. However, instead of ethanol, acetone was used and the catalyst was washed three times with acetone alone and then dried under high vacuum. Isolated yield: 20.0 g of CoBr2 (PPh3) 2. Catalyst Procedures Different pretreatment procedures with catalysts, additions of modifiers and order of additions of catalyst components to the reactor were performed as follows: Procedure a: Separate addition of catalyst and cocatalyst. Catalyst and cocatalyst were separately added to a reactor, first the catalyst and the polymerization was initiated by the addition of cocatalyst at the end. Procedure b: Premixing of catalysts with catalyst The desired amount of catalyst (eg, 0.05 ramol) was sealed in the dry box in a 10 ml folded lid bottle. The bottle was removed and placed under a nitrogen purge. Distilled toluene (2 ml) and 100 eq. of MAO (1.8 M in toluene) in the bottle. The purge needle was removed and the bottle remained under nitrogen pressure. A color change from blue-green to gold-yellow was observed in most cases. The premix was stirred for 5 minutes at room temperature before its injection into the reactor. When carbon disulfide (CS2) was used, it was added to the premix immediately after the cocatalyst. Procedures c and d: Silica support catalyst (c) and activated carbon (d) The desired amount of catalyst, silica (or activated carbon) and freshly distilled solvent was placed in a bottle without air under an atmosphere of inert nitrogen. The mixture was stirred at room temperature for 30 minutes. The solvent was then removed under high vacuum until it remained in free-flowing powder. Table 1 summarizes the loads of catalyst, support, solvent and catalyst resulting for different examples. Table 1. Summary of catalyst support data Example solvent support catalyst charge No. Ig) (g) (mi; mmol / g 4.5 A 1.0 g Silica 2.8g THF 25 ml 0.40 958-600 6 A 1.0 g coal 2.8g THF 25 mi 0.40 activated 10.11 B 1.2 g silica 4.0g chloride 35 mi 0.30 958-6000d methylene 13 C 0.4 g silica 3.0 g toluene 20 ml 0.29 958-6000 Procedures e and f: Adding Modifier A modifier was added to the reactor after of passivation, before the catalyst and cocatalyst. The molar ratio between the modifier and the cobalt compound was 5: 1. The modifiers were tributylamine (e) and gaseous ammonia (f). The modifiers were used to control the vinyl content. Procedure g: Addition of triphenylphosphine free ligand In this procedure, the catalyst and cocatalyst were premixed in a manner similar to process (b) but together with a free phosphine ligand. The catalyst (0.05 mmol) and 0.05 mmol of triphenylphosphine were sealed in a fold cap bottle under nitrogen. Distilled toluene (2 ml) and 200 eq. Were injected into the bottle. of MAO (1.8 M in toluene). The premix was stirred for 5 minutes at room temperature before its injection into the reactor. Laboratory-scale gas-phase polymerization procedure A reaction vessel (one liter, stirred metal autoclave) was charged with inert particulate material and dried with nitrogen at a temperature of 90 ° C for 1 hour. The temperature in the vessel was adjusted to the desired temperature, and a small initial charge of cocatalyst was added to passivate in vessel, for example, with 0.08 mmol of organoaluminum compound per gram of particulate material. Preferably, the organoaluminium used in the passivation is the same as the cocatalyst used in the subsequent polymerization. The vessel was purged under pressure with butadiene before the addition of the desired amount of catalyst. The catalyst and cocatalyst were either separately added or premixed. The vessel was pressurized with butadiene for polymerization. The feed rate was adjusted in such a way that a constant pressure was maintained during the reaction. The polymerizations were terminated using a stabilizer package and washing methanol alone or methanol and water and the product was dried in vacuum. Variations in the parameters of Examples 1-17 are presented in Table 2. Examples 1-3 is used CoCl2 (PPh3) 2, (catalyst A) at different temperatures between 20 and 50 ° C. The catalyst showed good activity in the gas phase polymerization. A polymer having a vinyl content comprised between 50% and about 60% was obtained. The molecular weight can be controlled by the polymerization temperature and ranged from about 111,000 to about 235,000 in terms of average molecular weight. Examples 4-9 are variations of Examples 1-3 in the following manner: Examples 4 and 6 demonstrate the use of catalyst supported on silica or activated carbon, respectively. Example 5 used DEACO as a cocatalyst. A higher vinyl content was obtained with DEACO (diethylaluminum chloride treated with 0.25 eq of H20) but the catalyst activity and the polymer molecular weight were higher with MAO as cocatalyst. Examples 7-8 employed modifiers, triethylamine and ammonia, respectively, to control the microstructure. Additives of this type can also function as gel suppressors, if desired. Example 9 is a variation of example 2, but with additional free triphenylphosphine ligand. The results were similar, except that the vinyl content decreased to 37%. Examples 10-13 employed CoBr2 (PPh3) 2 / (catalyst B). A very good catalyst activity was illustrated for unsupported catalyst (example 10) and supported catalyst (example 12). Examples 11 and 13 demonstrated polymerization at 60 ° C. Examples 14 and 15 illustrated the feasibility of cobalt (1-methylalyl) (buta-1,3-diene) (triphenylphosphine) (catalyst C) for the gas phase polymerization of butadiene to produce 1,2-vinyl polybutadiene. Example 16 used CoCl2 (pyridine) 4 (catalyst D) in combination with free ligand, triphenylphosphine (equimolar). A good catalyst activity provided a polymer with high molecular weight and 35.7% vinyl bonds. Example 17 showed the production of syndiotactic high vinyl polybutadiene. The catalyst used was Co (acac) previously contacted with 100 eq. of MAO and 3 eq. of modifier CS2. The polymer was of very high crystallinity with a melting point of 205.7 ° C by DSC, indicating a highly syndiotactic raised vinyl BR. The product was insoluble in toluene.

Claims (1)

1. CLAIMS A process for the preparation of a vinyl polybutadiene comprising the polymerization of 1,3-butadiene in a gas phase reactor under polymerization conditions using an inert gas in the presence of a catalyst, comprising: (a) a cobalt compound; (b) a compound selected from the group consisting of one of the following: phosphine, xanthogen, thiocyanide, carbon disulfide and mixture thereof; and (c) an organoaluminum compound; provided that when a cobalt phosphine is used, an additional phosphine (b) is not required. The process according to claim 1 wherein an inert particulate material is employed in the polymerization. The process according to claim 1 wherein the cobalt compound is selected from the group consisting of cobalt salts of inorganic acids; cobalt salts of organic acids; a cobalt complex; cobalt salts of higher fatty acids; cobalt salts of benzoic acids substituted by alkyl, aryl, aralkyl; cobalt naphthoate; cobalt salts of naphthoic acids substituted by alkyl, aralkyl and aryl; and mixtures thereof. The process according to claim 1 wherein the phosphine of (b) is a tertiary phosphine having the formula: PRR5R6, wherein P is phosphorus and R4, R5, and R6 are the same or different and are an alkyl, aryl, or well hydrogen; wherein the xanthogen is selected from the group consisting of diethylxanthogen sulfide, dimethylxanthogen sulfide, phenylxanthogen sulfide, tolylxanthogen sulfide, and mixtures thereof; and wherein the thioisocyanide compound is selected from the group consisting of phenyl thioisocyanide, tolyl thioisocyanide, and mixtures thereof. The process according to claim 1, wherein the organoaluminum is represented by one of the following formulas: (I) A1R3 (II) AlR1mX3-m (III) AlRn2 (OR3) 3-n where each R, R1, R2, R3 is the same or different and is a straight or branched chain alkyl group having from 1 to 12 carbon atoms, preferably from 1 to 8 carbon atoms, an aryl group (for example, phenyl or tolyl), or a hydrogen; X is halogen (F, Cl, Br, and I, with Cl being preferred); m is 0, 1, 1.5 or 2; and n is 1 or 2; where in (IV) and (V) each R is the same or different and is a hydrocarbon group, and m represents an integer from 2 to 100. The process according to claim 1, wherein the catalyst further comprises a modifier selected within of the group consisting of an amide, an aromatic aldehyde, a tertiary amine, and mixtures thereof. The process according to claim 1, wherein the catalyst comprises CoBr2 (PPh3) 2 and MAO and are used in a ratio between cobalt and organoaluminum of 1:40 to 400. The process according to claim 1, wherein the catalyst comprises CoCl2 (pyridine) 4, PPh3 and. MAO in a ratio of 1: 0.5 - 2:40 - 400. The process according to claim 1, wherein the amount of (a): (b): (c) is within a range of 1: 0.1: 10 a 1: 10: 1000. . A resin particle that is granular and free flowing comprising a core and a shell in which the core contains a mixture of inert particulate material and vinyl polybutadiene where the core mixture is more than 50% vinyl polybutadiene and the shell contains a mixture of inert material in particles where the shell mixture is more than 50% inert material in particle; and where the particle has a cobalt residue that falls within a range of 2 ppm to approximately 200 ppm. . A resin particle comprising an outer shell having a mixture of an inert particulate material and a vinyl polybutadiene, said inert particulate material is present in said outer shell in an amount greater than 75% by weight based on the weight of the the outer shell and an inner core having a mixture of said vinyl polybutylene and said inert particulate material, said vinyl polybutadiene is present in said inner core in an amount greater than 90% by weight based on the weight of said inner core.