Abstract: The present invention addresses heat integration in an alkylation/transalkylation process involving alkylation of an aromatic substrate with a C.sub.2 -C.sub.4 alklating agent coupled with separation to recover a monoalkylated aromatic product and liquid phase transalkylation of a polyalkylated product. Aromatic feedstock and a C.sub.2 -C.sub.4 alkylating agent are supplied to an alkylation reaction zone which is operated to produce an alkylated product. The output from the alkylation reaction zone initially travels through an arrangement of heat exchangers. From there, the alkylation effluent passes into the first separation zone which is operated to produce a lower boiling fraction comprising the aromatic substrate, which may be recycled to the alkylation reaction zone, and a higher boiling fraction comprising a mixture of monoalkylated and polyalkylated aromatics.

Abstract: The present invention provides a catalyst system that exhibits unprecedented catalyst efficiencies and control of desired properties in the polymer product. The catalyst system includes a new generation titanium catalyst in combination with an electron donor described by the formula: ##STR1## wherein R.sub.1 is an alkyl group containing a primary carbon atom attached to the silicon atom; R.sub.2 and R.sub.3 are alkyl or aryl groups; and R.sub.4 is an alkyl group with a primary carbon atom attached to the silicon atom; R.sub.1 and R.sub.4 are the same or different. R.sub.1 and R.sub.4 are preferably chosen from the group consisting of n-propyl, n-butyl and methyl; most preferably n-propyl and n-butyl with R.sub.1 and R.sub.4 being the same or, alternatively, most preferably, R.sub.1 is methyl and R.sub.4 is C.sub.3 or higher. The system has a catalyst efficiency of over 30 kg/g-cat.multidot.h as the Si/Ti mole ratio varies from 4-20 in the system. The system easily achieves efficiencies over 30 kg/g-cat.

Abstract: The invention is a process for using a metallocene catalyst system in polymerization of olefins. The metallocene is contacted with the Lewis acid. The aluminum alkyl is contacted with the olefin. The two mixtures are contacted with each other under polymerization conditions.

Abstract: The present invention discloses a composition of matter consisting of a high impact polystyrene exhibiting improved environmental stress crack resistance. The HIPS material is formed utilizing polybutadiene, polyisoprene, and copolymers thereof with styrene, having a Mooney viscosity exceeding about 35 and a gel content of up to about 28%. The present invention discloses the use of a combination of lubricant additives to obtain a HIPS material with higher ESCR values than either additive alone could provide, and also discloses the optimum level of each additive.

Abstract: A method of forming a polyolefin catalyst component which includes chlorinating magnesium ethoxide, and then treating the product first with an electron donor, particularly diethyl phthalate or di-isobutyl phthalate, at a relatively low donor level, and then second with a titanating agent, such as titanium tetrachloride, to produce a catalyst component. The catalyst component is activated with an aluminum alkyl cocatalyst. An external electron donor, such as an organosilane compound, is added for stereoselectivity control. The activated catalyst is used in the polymerization of olefins, particularly propylene, to obtain a polymer product with a broad molecular weight distribution.

Abstract: The present invention provides a catalyst and a process for increased catalyst activity and polymer yield. The catalyst system used in the process includes at least two supported metallocene catalyst precursor in combination with an oxyorganoaluminum. The process can be applied to the polymerization of olefins, preferably olefin of three carbon atoms and higher, particularly propylene. The catalyst activity and polymer yield for a dual supported metallocene catalyst are increased over that for a single supported metallocene catalyst. The polymer produced by this dual supported metallocene system has a relatively broad molecular weight distribution.

Abstract: Process for the production of ethylbenzene by alkylation over a silicalite alkylation catalyst with the subsequent transalkylation of diethylbenzene with the alkylation catalyst and conditions selected to retard xylene production and also heavies production. A feedstock containing benzene and ethylene is applied to a multi-stage alkylation reaction zone having a plurality of series-connected catalyst beds containing a pentasil molecular sieve alkylation catalyst which is silicalite of a predominantly monoclinic symmetry having a silica/alumina ratio of at least 275. The feedstock is supplied to the alkylation reaction zone to cause gas-phase ethylation of benzene at a flow rate to provide a space velocity of benzene over the catalyst to produce a xylene concentration in the product of about 600 ppm or less based upon the ethylbenzene content.

Abstract: A catalyst system for polymerization of olefins having increased molecular weight and melting point is disclosed. A chiral, stereorigid metallocene compound having a silicon hydrocarbyl compound as an interannular bridge between two cyclopentadienyl or substituted cyclopentadienyl rings described by the formula (C.sub.5 R'.sub.m) wherein R' is hydrogen or hydrocarbyl radical having from 1-20 carbon atoms, each R' being the same or different, is combined with an organoaluminum compound. The cyclopentadienyl ligands are coordinated with a metal of a group 4b, 5b, or 6b metal as designated in the Periodic Table of Elements. The metal is also bonded to a hydrocarbon radical or a halogen.

Abstract: A method of forming a polyolefin catalyst component which includes chlorinating a magnesium alkoxide, solubilizing the chlorinated magnesium alkoxide into a hydrocarbon solvent utilizing an alcohol, and then precipitating a solid from the solvent by the dropwise addition of titanium tetrachloride. Two more titanation steps follow, the first with an electron donor, the second without an electron donor, to produce a catalyst having an improved yield of polymer.

Abstract: Metallocene catalysts and their preparation and use in the polymerization of olefins. Specifically, the catalysts and processes relate to polymerization of olefins in which an aluminum ionizing agent containing a triphenylcarbenium ion is utilized in preparing the catalyst. The preparation of an olefin polymerization catalyst comprising a metallocene-type catalyst and triphenylcarbenium tetrakis(pentafluorophenyl)aluminate is disclosed.

Abstract: Stereospecific catalysts and processes for the stereotactic polymerization of ethylenically unsaturated monomers, specifically C.sub.3 -C.sub.4 alpha olefins involving a molecular sieve supported metallocene catalyst comprising a stereospecific metallocene catalyst component and a co-catalyst component. The metallocene catalyst component incorporates a metallocene ligand structure having two sterically dissimilar cyclopentadienyl ring structures coordinated with the central transition metal atom. Both the metallocene catalyst component and the co-catalyst component are supported on a molecular sieve having an average effective pore size which is less than the kinetic diameter of at least one of said ring structures. This supported catalyst is contacted in a polymerization reaction zone with an ethylenically unsaturated monomer which contains 3 or more carbon atoms or which is a substituted vinyl compound under polymerization conditions to produce stereospecific polymerization of the monomer.

Abstract: Bituminous compositions modified with self-adhesive cold-application polymers generally used for manufacturing of watertight panels, said compositions comprising a mixture containing a rubbery styrene-diene polymeric mixture, one or more tackifying resins, and bitumen.

Abstract: The present invention is a catalyst system to produce polymer blends in a single reactor, polymer blends of isotactic polyolefins and syndiotactic polyolefins. The catalyst system is a combination of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The multi-catalyst system is obtained by mixing the components of at least one metallocene catalyst and at least one conventional supported Ziegler-Natta catalyst. The metallocene catalyst comprises solid complx of a metallocene compound and an ionizing agent. The conventional supported Ziegler-Natta catalyst comprises an aluminum alkyl and a transition metal compound with, optionally, an electron donor.

Abstract: Medium-chain olefins containing as impurities 2-alkyl substituted isomers having a close boiling point are purified by (i) passing over a solid acid catalyst under mild conditions to selectively double-bond isomerise said impurities, and (ii) separating said isomerised olefins by distillation.

Abstract: The present invention provides a process for control of desired properties in the polymer product. The catalyst system used in the process includes a supported metallocene catalyst precursor in combination with an oxyorganoaluminum. The process can be applied to the co-polymerization of propylene and ethylene. The randomness of the ethylene incorporation of the co-polymer product is increased as the amount of ethylene in the feed is increased. The amount of ethylene in the feed is up to 6 wt. % with a resulting amount of ethylene incorporated into the copolymer product up to 4 mole %.

Abstract: This invention relates to a process for making a catalyst in which a metallocene is included in the synthesis of a Ziegler-Natta catalyst and a process for using the catalyst in the polymerization of olefins, specifically, propylene, to produce a polymer product with broad polydisperisty.The catalyst may be synthesized by:1) selecting a solid component comprising a magnesium dialkoxide;2) adding a chlorinating agent;3) adding a titanating agent;4) adding a metallocene prior to step 2), after step 2), prior to step 3) or after step 3) and5) adding an aluminum alkyl cocatalyst.

Abstract: Metallocene catalysts and their preparation and use in the polymerization of olefins. Specifically, the catalysts and processes relate to polymerization of olefins in which an aluminum ionizing agent containing a triphenylcarbenium ion is utilized in preparing the catalyst. The preparation of an olefin polymerization catalyst comprising a metallocene-type catalyst and triphenylcarbenium tetrakis(pentafluorophenyl)aluminate is disclosed.

Abstract: The present invention relates to polypropylene fibers and nonwoven fabrics produced from spunlaid or staple fibers having improved natural bulk. Said polypropylene fibers are made of a blend of sPP and iPP.

Abstract: A process of polymerizing ethylene with a catalyst using a single metallocene catalyst comprising a bridged metallocene compound having two cyclopentadienyl rings, one substituted with a bulky group in a distal position and one substituted such that a fused ring, substituted or unsubstituted, is formed, which produces a copolymer of ethylene. The metallocene catalyst promotes simultaneous oligomerization of a fraction of ethylene to form a comonomer in situ and copolymerization of the remaining ethylene and the comonomer to form a copolymer.

Abstract: A improved process is provided for the alkylation of aromatic compounds under at least partial liquid phase conditions, and in the presence of a zeolite-type alkylation/transalkylation catalyst. In accordance with the present process, a diluted aromatic hydrocarbon feedstock containing C.sub.5 -C.sub.7 olefins is brought into contact with a diluted olefinic feedstream in the presence of the alkylation/transalkylation catalyst. Prior to contact with the olefinic feedstream, C.sub.5 -C.sub.7 olefins present in the aromatic hydrocarbon feedstock are selectively hydrogenated.