Albemarle Corporation

Ethyl Corporation

Ablemarle Corporation

John F Balhoff

Ronny W Lin

Charles H Kolich

Troy E DeSoto

Jamie R Strickler

Martin B Berdon

Arthur G Mack

John M Power

Chi Hung Cheng

Bruce C Peters

Douglas W Luther

Jeffrey Todd Aplin

David W Owens

Robert C Herndon

David A Lee

Meng-Sheng Ao

Hassan Y Elnagar

Donald E Balhoff

Bruce C Berris

Arcelio J Malcolm

Gerald M Sulzer

Steven G Karseboom

Michael J Turpie

Phillip R Devrou

Jr Robert C Herndon

Brominated styrenic polymer is recovered from solution in a vaporizable solvent by converting the solution in a devolatilization extruder into a brominated styrenic polymer melt or flow and a separate vapor phase comprised predominately of vaporizable solvent, recovering the melt or flow from the devolatilization extruder, and allowing or causing the melt or flow to solidify. The solidified brominated styrenic polymer can be subdivided into a powder or pelletized form. Pellets so made have improved hardness and/or crush strength properties along with reduced formation of fines. Brominated anionic styrenic polymer is preferably used in the process.

Process technology for recovering brominated styrenic polymers from reaction mixtures in which they are formed and/or converting such mixtures into pellets or into granules or pastilles

Preparing brominated styrenic polymer by maintaining a mixture formed from (i) brominating agent, (ii) a solvent solution of styrenic polymer, and (iii) aluminum halide catalyst, at &#x2212;20 to +20&#xb0; C., and terminating bromination in 20 minutes or less. New brominated anionic styrenic polymers have better melt flow and/or lower initial &#x394;E values than the best previously-known brominated anionic styrenic polymers. Other features of such new polymers include high thermal stabilities at 320&#xb0; C. and/or very low initial color values. Brominated styrenic polymers, especially brominated anionic styrenic polymers, are useful as flame retardants for thermoplastic polymers.

Brominated styrenic polymers and their preparation

Concurrently fed into a reaction zone held at about 10&#xb0; C. or less are brominating agent, aluminum halide catalyst, and a solution of anionic styrenic polymer having a GPC Mn about 2000-30,000. The components are in at least two separate feed streams. The feeds are proportioned to maintain (a) the amount of aluminum halide being fed at about 0.8 mole percent or less based on the amount of aromatic monomeric units in the polymer being fed, and (b) amounts of brominating agent and unbrominated polymer in the reaction zone that produce a final washed and dried polymer product containing about 60-71 wt % bromine. The catalyst is deactivated, bromide ions and catalyst residues are washed away from the reaction mixture, and the brominated anionic styrenic polymer is recovered and dried. The dried polymer has a volatile bromobenzene content of about 600 ppm (wt/wt) or less as well as other beneficial properties.

Brominated anionic styrenic polymers and their preparation

Bromination of styrenic polymer is carried out in a closed reaction system to retain HX coproduct (where HX is HBr or HCl, or both) in the bromination reaction mixture at superatmospheric pressure. Preferably, the reaction mixture which includes the brominated styrenic polymer and substantially all of the HX coproduct formed is discharged into an aqueous quenching medium. By operating in this manner, the reaction is terminated and the brominated styrenic polymer of desired bromine content and substantially all HX coproduct are captured in the same operation, process equipment costs are reduced, and processing of the reaction mixture is facilitated.

Preparation of brominated styrenic polymers or resins

Epoxyalkanes are subjected to at least one of the following washing operations: (1) washing with aqueous inorganic base, and then with aqueous borohydride, or vice versa; or (2) washing with an aqueous solution of both inorganic base and borohydride. Undesirable odor is reduced or eliminated from alkanediol(s), if produced from the treated epoxyalkane(s) by hydrolysis. Use of such washing procedures in the production of alkanediols is also described.

Preventing undesired odor in and/or purifying alkanediols

Chloropentafluorobenzene or bromopentafluorobenzene is formed by heating perhalobenzene, C F X where n is 0 to 4, and each X is, independently, a chlorine or bromine atom, with alkali metal fluoride, and an aminophosphonium catalyst (e.g., (Et N) PBr). The resultant chloropentafluorobenzene or bromopentafluorobenzene can be converted into a pentafluorophenyl Grignard reagent or a pentafluorophenyl alkali metal compound. This in turn can be converted into tris(pentafluorophenylborane), which can be converted into a single coordination complex comprising a labile tetra(pentafluorophenyl)boron anion (e.g., a trialkylammonium tetra(pentafluorophenyl)boron complex or an N,N-dimethylanilinium tetra(pentafluorophenyl)boron complex). The complex can be used in the preparation of an active catalyst by mixing the complex with a cyclopentadienyl metal compound containing a Group 4 metal in suitable solvent or diluent so that the cation of the complex reacts irreversibly with a ligand of the cyclopentadienyl compound, and such that the pentafluorophenyl anion forms a non-coordinating ion pair with a resulting cation produced from the cyclopentadienyl metal compound. Alternatively, the tris(pentafluorophenylborane) can be contacted with a metallocene of the formula LMX wherein L is a derivative of a delocalized pi-bonded group imparting a constrained geometry to the metal active site and where L contains up to 50 non-hydrogen atoms, M is a Group 4 metal, and each X is, independently, hydride, or a hydrocarbyl, silyl, or germyl group having up to 20 carbon, silicon, or germanium atoms to form a catalyst having a limiting charge separated structure of the formula LMX&oplus; XA&ominus; wherein A is an anion formed from the tris(pentafluorophenyl)borane.

Halogen exchange reactions in preparing catalysts and their precursors

4-Fluorobenzaldehyde is produced by a commercially feasible process. The process comprises heating a mixture of fluorobenzene and a strong Lewis acid with dissolved hydrogen halide in an atmosphere of carbon monoxide at about 45 to about 100&deg; C. and at a total pressure of about 150 psig up to the maximum pressure rating of the reactor. Formed is a reaction mass containing a Lewis acid complex of 4-fluorobenzaldehyde and at least a halobis(fluorophenyl)methane by-product. The complex is broken by quenching the reaction mass with a Lewis acid-solvating liquid to liberate 4-fluorobenzaldehyde. By-product halobis(fluorophenyl)methane is converted to di(fluorophenyl)methanol to avoid potential corrosion problems and formation of light sensitive color bodies in the recovered 4-fluorobenzaldehyde.

Production of 4-fluorobenzaldehyde

Chloropentafluorobenzene or bromopentafluorobenzene is formed by heating perhalobenzene, C,F,X,where n is 0 to 4, and each X is, independently, a chlorine or bromine atom, with alkali metal fluoride, and an aminophosphonium catalyst (e.g., (Et,N),PBr). The resultant chloropentafluorobenzene or bromopentafluorobenzene can be converted into a pentafluorophenyl Grignard reagent or a pentafluorophenyl alkali metal compound. This in turn can be converted into tris(pentafluorophenylborane), which can be converted into a single coordination complex comprising a labile tetra(pentafluorophenyl)boron anion (e.g., a trialkylammonium tetra(pentafluorophenyl) boron complex or an N,N-dimethylanilinium tetra(pentafluorophenyl)boron complex). The complex can be used in the preparation of an active catalyst by mixing the complex with a cyclopentadienyl metal compound containing a Group 4 metal in suitable solvent or diluent so that the cation of the complex reacts irreversibly with a ligand of the cyclopentadienyl compound, and such that the pentafluorophenyl anion forms a non-coordinating ion pair with a resulting cation produced from the cyclopentadienyl metal compound. Alternatively, the tris(pentafluorophenylborane) can be contacted with a metallocene of the formula LMX,wherein L is a derivative of a delocalized pi-bonded group imparting a constrained geometry to the metal active site and where L contains up to 50 non-hydrogen atoms, M is a Group 4 metal, and each X is, independently, hydride, or a hydrocarbyl, silyl, or germyl group having up to 20 carbon, silicon, or germanium atoms to form a catalyst having a limiting charge separated structure of the formula LMX,XA,wherein A is an anion formed from the tris(pentafluorophenyl)borane.

It has been found possible to separate catalytically-active aminophosphonium catalysts from mixtures composed predominately of aminophosphonium catalyst residue(s) and heavy ends from a halogen exchange reaction conducted in an aprotic solvent/diluent by extracting such mixtures with a neutral or acidic aqueous extraction solvent medium. Various ways of isolating from the halogen exchange reaction product mixture a mixture composed predominately of aminophosphonium catalyst residue(s) and heavy ends are described. Halogen exchange processes in which the catalytically-active aminophosphonium catalysts are separated for reuse are also described. Since aminophosphonium catalysts are expensive, the present process technology fulfills a need which has existed for an effective way of recovering such catalysts in catalytically active form enabling reuse of such materials, especially as halogen exchange catalysts.

Catalyst recovery for halogen exchange reactions

A metallocene having one or two hydrocarbyl groups bonded to a Group 4 metal are produced from a crude impure pasty or non-wet mixture containing at least 50% by weight of a metallocene having two halogen atoms bonded to a Group 4 metal atom, by (a) mixing liquid aromatic hydrocarbon with the crude impure pasty or non-wet mixture; (b) mixing a solution of an organolithium compound in a suitable anhydrous ether or paraffinic hydrocarbon solvent or a mixture thereof, with the mixture from (a) and agitating the resulting mixture so that lithium halide solids are formed; and (c) separating the solids and recovering the resultant liquid portion which is mainly a solution of the metallocene having one or two hydrocarbyl groups bonded to a Group 4 metal. Additional optional steps include (d) replacing the original solvent from the solution from (c) with a liquid paraffinic hydrocarbon diluent to form a slurry of product solids; and (e) recovering the product metallocene solids. Preferred organolithium compounds have the formula, RLI.nLiX, where R is tert-alkyl, aryl, alkaryl, benzyl, or alkyl-substituted benzyl, or most preferably, methyl, and X is Br or I.

Metallocene synthesis

Enhanced synthesis of racemic metallocenes

Bridged metallocene compounds are produced by a process of promising commercial utility for plant-sized operations. One of the key steps of the process involves converting a deprotonated silicon-, germanium- or tin-containing ligand into the metallocene. Preferably, and in accordance with an embodiment of the invention, this is accomplished to great advantage by adding a diamine adduct of a Group IV, V, or VI metal tetrahalide to a solution or slurry formed from a deprotonated silicon-, germanium- or tin-containing ligand and an organic liquid medium so as to form a metallocene. The overall process of the invention involves the direct conversion of benzoindanones to benzoindanols which, without isolation, are converted to benzoindenes. Thereupon the benzoindenes are bridged by deprotonating the benzoindenes with a strong base such as butyllithium and reacting the resultant deprotonated product with a suitable silicon-, germanium- or tin-containing bridging reactant such as dichlorodimethylsilane. The resultant bridged product is deprotonated with a strong base such as butyllithium and reacted with a suitable Group IV, V, or VI metal-containing reactant such as ZrCl.sub.4 to provide a silicon-, germanium- or tin-bridged Group IV, V, or VI metal complex, such as a dihydrocarbylsilyl-bridged zirconocene complex.

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Baton Rouge, LA, United States of America

John F Balhoff