Abstract: This invention relates to a process for the synthesis of addition polymers containing branches upon branches and having a polymerizable olefin end group by a convenient one-pot copolymerization of selected vinyl monomers with chain polymerization initiators and a method to provide olefin end groups by chain transfer or termination agents; and polymers produced thereby.

Abstract: There is disclosed a method for synthesizing polyolefins having a silyl group at one terminus, the method comprising reacting a monomer of an a-olefin (C.ltoreq.3.ltoreq.10) and a tetrasubstituted silyl radical in the presence of a metallocene catalyst.

Abstract: There is disclosed a method for synthesizing polyolefins having a silyl group at one terminus, the method comprising reacting a monomer of an .alpha.-olefin (C.ltoreq.3.ltoreq.10) and a tetrasubstituted silyl radical in the presence of a metallocene catalyst.

Abstract: A novel process for the preparation of Ziegler-Natta catalyst systems containing, as active components,a) a titanium-containing solid component which contains titanium, magnesium, halogen and a carboxylic ester and, as a cocatalyst,b) an aluminum compound andc) if required, a further electron donor is described. Ziegler-Natta catalyst systems which are obtainable by this process, the preparation of polymers of propylene with the aid of these catalyst systems, the polymers obtainable thereby and films and moldings of these polymers are also described.

Abstract: The present invention provides substituted phenols which are effective to inhibit polymer formation during the manufacture of acrylonitrile. Preferred substituted phenols are (a) hindered phenols, nonhindered phenols, and partially hindered phenols, or (b) combinations of hindered phenols with nonhindered or partially hindered phenols. A most preferred substituted phenol is p-nitrosophenol. In a preferred embodiment, the substituted phenols (with the exception of p-nitrosophenol) are combined with hydrogen transfer agents.

Abstract: The invention provides a catalyst composition, comprising: (a) an organolithium compound; and, (b) an organic acid salt of lanthanide series element; wherein: (1) only components (a) and (b) are required to promote the synthesis of 1,4-trans-polybutadiene; (2) the ratio of component (a) to component (b) is selected to maximize formation of the trans structure of said 1,4-trans-polybutadiene; and, (3) components (a) and (b) are selected for enabling further diblock synthesis. The invention further contemplates a process for using the catalyst to synthesize 1,4-trans-polybutadiene and other polymers and copolymers having trans configuration in the conjugated diene monomer contributed units.

Abstract: A method of terminating a gas phase polymerization of an olefin to be conducted subsequent to producing a polyolefin by feeding a gaseous olefin into a fluidized bed reactor to polymerize the gaseous olefin while holding solid particles containing a catalyst in a fluid state, said method comprising introducing a deactivator in the fluidized bed reactor through at least two deactivator introduction ports of the fluidized bed reactor so as to terminate the gas phase polymerization. The height of the fluidized bed is generally at least 3 m. The deactivator is preferably introduced through deactivator introduction ports disposed at heights Ha=-0.3 D to 0.3 D (a) and Hb=0.3 D to 2.0 D (b) (D is the inside diameter of the fluidized bed reactor (cm)). After the termination of the polymerization, the gas phase polymerization can directly be resumed.

Abstract: The invention describes a dental composition, delivery system and method for making temporary crowns and bridges in which the composition comprises two free-radical polymerizable pastes, one a catalyst paste and the other a base paste, wherein the catalyst paste comprises at least one polymerizable monomer, at least one polymerization initiator which is a peroxide oxidizing agent, at least one first polymerization inhibitor and a filler, and wherein the base paste comprises at least one polymerizable monomer, at least one polymerization accelerator, at least one second polymerization inhibitor, at least one non-polymerizable plasticizer and a filler. These catalyst and base pastes are stored in a dual cartridge from which they can be dispensed with a dispenser, preferably in a 1:1 volume ratio, and can be mixed in a static mixer to form a moldable polymerizing material, which is then applied to a prepared area of one or more teeth in a patient's mouth to form a crown or a bridge.

Abstract: A polymerization process is provided comprising contacting under polymerization conditions a catalyst, a taming agent, ethylene and optionally a comonomer, wherein the catalyst comprises chromium oxide, titanium oxide and an inorganic refractory oxide, wherein the taming agent is selected from the group consisting of water, alcohols, aldehydes, ketones, esters, and organic acids and mixtures thereof. The process is especially suited for polymerizing ethylene resins suitable for blow molding use.

Abstract: The present invention relates to a method of terminating a free-radical initiated emulsion polymerization by utilizing a shortstopping agent that contains a stable nitroxyl free-radical or is capable of forming a stable nitroxyl free radical in situ. Besides more effective stopping of polymerization, the present invention does not contain nitrosamine precursors nor is the shortstop agent easily removed during latex and polymer processing.

Abstract: Disclosed is a process for the preparation of a polymer which comprises effecting bulk polymerization of a mixture of at least one monomer, a free radical polymerization initiator, and a stable free radical agent until from about 10 to about 50 weight percent of the monomer has been polymerized; optionally adding additional free radical initiator; optionally adding a colorant; dispersing with a high shear mixer the aforementioned partially polymerized mixture in water containing a stabilizing component selected from the group consisting of non-ionic and ionic water soluble polymeric stabilizers to obtain a suspension of particles with an average diameter of from about 0.1 to about 10 microns; polymerizing the resulting suspension to form said polymer.

Abstract: A continuous process for the polymerization of one or more alpha-olefins in the gas phase in the presence of a chromium based catalyst, under polymerization conditions including the reaction temperature, the pressure, and the target oxygen to alpha-olefin molar ratio operating point required for desired resin properties.

Abstract: A process for producing a styrenic polymer having the syndiotactic configuration which process comprises a plurality of polymerization stages, at least one polymerization stage selected as desired from the plurality of polymerization stages being a polymerization stage in which hydrogen is introduced; in accordance with the present invention, efficient control of molecular weight and molecular weight distribution is enabled. By increasing activity of the polymerization catalyst, the amount of the catalyst and the amount of residual metals can be decreased, and the cost of production can be decreased.

Abstract: Polymers of alkyl-1-vinylimidazoles, a process for preparing polymers of alkyl-1-vinylimidazoles by free-radical polymerization of a monomer mixture comprising(a) 10-100% by weight of at least one alkyl-1-vinylimidazole and(b) 0-90% by weight of 1-vinylpyrrolidone, 1-vinylcaprolactam, 1-vinyltriazole, 1-vinylimidazole, 1-vinyloxazolidinone or mixtures thereof,(c) 0-30% by weight of other monoethylenically unsaturated monomers and(d) 0-10% by weight of a monomer containing at least 2 monoethylenic double bondsin water, at least one C.sub.1 -C.sub.4 -alcohol or mixtures thereof, and the use of polymers which comprise at least 10% by weight of an alkyl-1-vinylimidazole as copolymerized unit as additive to detergents to inhibit transfer of dyes during the washing process.

Abstract: An improved method of free radical polymerization conducted in the presence of a relatively low molecular weight macromonomer such as can be made with a metal chelate chain transfer catalyst. This method has various uses, including reducing the molecular weight of a variety of crosslinkable polymers and copolymers.

Abstract: A process for the free radical initiated polymerization of unsaturated species characterized by the use of compound of Formula (I) as chain transfer agents: ##STR1## wherein: X is selected from hydrogen; CN; optionally substituted aryl; COOH; COOR; C(O)NHR.sup.6 ; C(O)NR.sup.7 R.sup.8 ; and halogen;Q is selected from COOR.sup.1 ; CN; and C(O)NR.sup.7 R.sup.8 ;Y is selected from hydrogen; C.sub.1 to C.sub.6 alkyl; C.sub.1 to C.sub.6 alkyl substituted with one or more substituents selected from hydroxy, amino, C.sub.1 to C.sub.6 alkoxy, C.sub.1 to C.sub.6 alkoxycarbonyl, halogen, CN and optionally substituted aryl; C.sub.1 to C.sub.6 alkenyl; and C.sub.1 to C.sub.6 alkynyl;Z is selected from COOR.sup.2 ; CN; and optionally substituted aryl;R.sup.3 and R.sup.4 are the same or different and are selected from hydrogen C.sub.1 to C.sub.4 alkyl and halogen; or R.sup.3 and R.sup.

Abstract: A polymerization apparatus comprising a cylindrical polymerization vessel having a straight cylindrical section, a cooling means for cooling the contents of the polymerization vessel, and paddle impellers, each fixed to a central shaft positioned along the center line of the vessel and spaced apart at predetermined positions, each impeller having impeller blades for agitating the contents inside the polymerization vessel as the shaft is rotated, wherein the polymerization vessel has an inner capacity of 100 m.sup.3 or more and has a ratio L/D (the length L of the cylindrical section to the inner diameter D of the vessel) of at least 1.

Abstract: A method for the solution or amulsion polymerization of ethylenically unsaturated monomers, styrene, and other free radical polymerizatable monomers in aqueous media in which a cobalt chain transfer agent is used which has both hydrolytic stability and solubility in water and in the organic phase with preferential solubility in the organic phase.

Abstract: This invention relates to a process for transitioning between incompatible polymerization catalyst systems. Particularly, the invention relates to a process for transitioning from an olefin polymerization reaction utilizing a traditional Ziegler-Natta catalyst system to a metallocene-olefin polymerization reaction.

Abstract: This invention relates to a process for transitioning between incompatible polymerization catalyst systems. Particularly, the invention relates to a process for transitioning from an olefin polymerization reaction utilizing a traditional Ziegler-Natta catalyst system to a metallocene-olefin polymerization reaction.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: A modified acrylic urethane prepolymer composition and an unsaturated polyester resin composition to which the prepolymer has been added. The prepolymer composition includes an acrylic urethane prepolymer prepared by the reaction of diisocyanate, like MDI, with an hydroxyl-containing acrylate monomer, such as a pentaerythritol triacrylate, which prepolymer composition may contain a styrene monomer and an inhibitor, such as benzoquinone, to retard the reaction of the prepolymer and styrene monomer prior to the addition of the prepolymer composition into the polyester resin composition. The employment of the modified urethane prepolymer composition provides for the reduction in the amount of styrene monomer used in the unsaturated resin composition and also provides for improved chemical and physical properties of the cured, unsaturated resin composition, such as a reduction in glass roll-out when the resin composition is employed with fiberglass.

Abstract: A macromonomer composition, wherein at least 80 mol % of the macromonomer is a random copolymer of 2 to 1,000 units of monomers and having a very high content of acid monomers, i.e. >50% by weight of acid monomers, and an end group linked to the random copolymer having the formula:CH.sub.2 .dbd.C(C(O)OR.sub.1)(CH.sub.2 .paren close-st.,wherein R.sub.1 is selected from the group consisting essentially of H; an alkyl group of 1 to 8 carbon atoms; and X.sub.n (CH.sub.2 CH.sub.2 O).sub.m --R.sub.4 wherein n is 0 or 1, X is an alkyl, aryl or alkaryl diradical connecting group of 1 to 9 carbon atoms, m is 2 to 50, and R.sub.4 is H or an alkyl group of 1 to 4 carbon atoms. These macromonomers can be used effectively in solution form to prepare structured polymers such as block copolymers and graft copolymers for industrial applications.

Abstract: A process for producing a branched polymer from a vinyl aromatic monomer comprising:A) contacting a vinyl aromatic monomer with a difunctional anionic initiator under conditions such that a dianion macromer is formed,B) contacting the dianion macromer with a multifunctional coupling agent having at least 3 reactive sites under polymerization conditions such that branches form during polymerization, andC) contacting the product of step B with a terminating agent under conditions such that the reactive sites are terminated.

Abstract: The present invention provides a method of anionic synthesis of stable macrocyclic polymers that are compounded to form vulcanizable elastomeric compounds exhibiting reduced hysteresis properties. Cyclic organometallic compounds containing divalent metal atoms of Groups IIA and IIB of the Periodic System are employed as initiators of anionic polymerization of conjugated diene, vinyl aromatic and/or triene monomers. Coupling of the living ends of the resulting macrocyclic polymers or copolymers with a coupling agent or a coupling agent that is also a functionalizing agent results in stable macrocyclic polymers with improved hysteresis properties.

Abstract: The invention is a practical process for anionically synthesizing commercially significant quantities of macrocyclic polymers from polar and/or non-polar monomers by using Group IIA and IIB metal cyclic organometallic initiators. Activation of the ring metal atom results in anionic polymerization of the monomers by addition into the initiator ring at the bonds between the atom and its two adjacent carbon atoms, the metal atom acting as a bridge between the two living ends of the propagating chain. Coupling of the cyclic polymer living ends by coupling agents produces macrocyclic polymers that are stable in air and moisture and that exhibit desirable properties, such as low viscosities at high molecular weights. Such macrocyclic polymers provide enhanced polymer processability during molding, extruding and the forming of films.

Abstract: This invention relates to a process for transitioning between polymerization catalyst systems which are incompatible with each other. Particularly, the invention relates to a process for transitioning from an olefin polymerization reaction utilizing a traditional Ziegler-Natta catalyst system to a metallocene-olefin polymerization reaction.

Abstract: This invention relates to a process for transitioning between incompatible polymerization catalyst systems. Particularly, the invention relates to a process for transitioning from an olefin polymerization reaction utilizing a traditional Ziegler-Natta catalyst system to a metallocene-olefin polymerization reaction.

Abstract: The present invention relates to a method of reducing hydrolysis and coupling of substituents of siloxane end capped polymers containing hydrolyzable substituents during contact with water. The Mooney viscosity of siloxane terminated polymers is stabilized during such contact by treating the polymer with a stabilizing amount of stabilizing agent selected from the group consisting of: an acid, an acyl halide, methane sulfonic acid, toluene sulfonic acid, sulfuryl chloride, thionylchloride, phosgene, carbon dioxide, sulfur dioxide, sulfur trioxide, SOCl.sub.2 and SO.sub.2 Cl.sub.2, prior to contacting the siloxane terminated polymer with water.

Abstract: A water-soluble polyvinyl 5-membered lactam having a molecular weight ranging from about 1000 to about 20,000 and chain-terminated with a compound selected from the group consisting of compounds of the following formulas ##STR1## wherein R and R.sup.1 are C.sub.1 to C.sub.4 alkyl or substituted alkyl; n is 0 to 20; R.sup.II is ethylene; R.sup.III is C.sub.1 to C.sub.24 alkylene or substituted alkylene; and R.sup.IV is C.sub.1 to C.sub.4 alkyl or substituted alkyl; can be prepared by polymerizing an N-vinyl 5-membered lactam in a liquid solvent-chain terminator compound of the formula (I) or (II) in the presence of a free radical initiator. The lactam polymer so-obtained may be activated and grafted to (conjugated with) a drug or an enzyme to alter the properties thereof.

Abstract: A polymerization method carried out in the presence of unsaturated organic peroxide chain transfer agents is disclosed. Also disclosed are (co)polymers and oligomers made by this process and articles of manufacture comprising one or more (co)polymers or oligomers made by this process. Furthermore, the use of these unsaturated organic peroxides as chain transfer agents is disclosed. The present process reduces the severe retardation of polymerization observed for unsaturated organic peroxide chain transfer agents of the prior art and, in some cases, even improves the monomer conversion in comparison to the control.

Abstract: There is disclosed a method for synthesizing polyolefins having a silyl group at one terminus, said method comprising reacting(A) a monomer selected from the group consisting of ethylene and a combination of ethylene and an .alpha.-olefin; and(B) a silane having the formulaR.sup.2 R.sup.3 R.sup.4 SiHwherein R.sup.2, R.sup.3 and R.sup.4 each represents a monovalent group selected from the group consisting of hydrogen, alkyl having 1 to 4 carbon atoms, aryl, alkylaryl, arylalkyl, alkoxy having 1-4 carbon atoms, phenoxy, fluorinated alkyl having 3 to 6 carbon atoms, a dialkylamino group in which the alkyl groups contain 1 to 4 carbon atoms and a diorganopolysiloxane chain containing 1 to 10 siloxane units, said reaction taking place in the presence of(C) a catalyst comprising a metallocene compound.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: Addition polymers derived from norbornene-functional monomers are terminated with an olefinic moiety derived from a chain transfer agent selected from a compound having a terminal olefinic double bond between adjacent carbon atoms, excluding styrenes, vinyl ethers, and conjugated dienes and at least one of said carbon atoms has two hydrogen atoms attached thereto. The addition polymers of this invention are prepared from a single or multicomponent catalyst system including a Group VIII metal ion source. The catalyst systems are unique in that they catalyze the insertion of the chain transfer agent exclusively at a terminal end of the polymer chain.

Abstract: There is provided a process for producing a cyclic olefin copolymer by copolymerizing (A) ethylene and (B) a particular cyclic olefin in the presence of (C) a metallocene catalyst and (D) a small amount of an .alpha.-olefin having 3 to 20 carbon atoms. According to the said process, said copolymer can be produced at a high activity and its molecular weight can be controlled in a wide range. The copolymer produced by the said process has excellent properties inherent to the cyclic olefin copolymer.

Abstract: A one-step polymerization process for producing a bimodal resin having a distinct low molecular weight portion and a high molecular weight portion includes initiating an anionic polymerization of a monomer or monomers to produce living polymer chains, terminating a portion of the living polymer chains, and completing the polymerization of the remaining living polymer chains. The bimodal resin is useful, for example, in high gloss, low melt toner applications.

Abstract: A process comprising contacting propylene in two reaction zones connected in series, under gas phase polymerization conditions, with a transition metal catalyst system comprising(a) introducing the catalyst into the first reaction zone;(b) partially deactivating the catalyst and simultaneously increasing the monomer level to achieve a desired resin productivity in the first zone; and(c) transferring resin together with catalyst from the first zone to the second zone having purged the deactivator or added activator in sufficient amount to achieve a desired resin productivity in the second zone.

Abstract: In the preparation of polyolefin in a vapor phase polymerization using catalysts comprising a solid catalyst component containing titanium and/or vanadium; and magnesium and an organoaluminum compound, when the reaction is stopped for a certain period of time, the restarting of reaction is possible by feeding in the first place an organoaluminum compound into the reaction system with retaining of polymer particles in the reactor.

Abstract: The invention relates to a polymerization process for the production of polymethacrylate molding compounds having high heat deflection temperature and high stability against thermal degradation, are prepared by polymerizing methacrylate monomer in a reaction medium such that at least 70 wt. % of the polymethacrylate molding compound is produced at a monomer concentration in the reaction medium of at least 5 mol per liter.

Abstract: A photopolymerized acrylic pressure-sensitive adhesive having excellent heat-resistance, an adhesive sheet using the adhesive, and methods for producing the adhesive and the adhesive sheet, are disclosed. The pressure-sensitive adhesive sheet having excellent heat resistance comprising a photopolymerization product of a composition comprising;a) 100 parts by weight of monomers comprising from 70 to 100% by weight of a (meth)acrylic acid alkyl ester having from 2 to 14 carbon atoms in the alkyl moiety, and from 30 to 0% by weight of a monoethylenically unsaturated monomer copolymerizable with the (meth)acrylic acid alkyl ester,b) from 0.02 to 20 parts by weight of a radical chain inhibitor,c) up to 5 parts by weight of a polyfunctional (meth)acrylate as a crosslinking agent, andd) from 0.01 to 5 parts by weight of a photopolymerization initiator.

Abstract: The capping of anionic polymers to make functionalized polymers is used to make heterotelechelic polymers by using a protected functional initiator to polymerize a polymer comprising a conjugated diene and then capping the polymer with low surface energy fluorocarbons. The protected functional groups are stable under a variety of conditions and then readily convert to more reactive terminal functional groups useful for making sealants, coatings, molded or extruded goods and fibers having low surface energy.

Abstract: A single component ionic catalyst consists essentially of an organonickel complex cation, and a weakly coordinating neutral counteranion. The cation is a neutral bidentate ligand removably attached to a Group VIII transition metal in an organometal complex. The ligand is easily displaced by a norbornene-type (NB-type) monomer in an insertion reaction which results in an unexpectedly facile addition polymerization. A NB-type monomer includes NB or substituted NB, or a multi-ringed cycloolefin having more than three rings in which one or more of the rings has a structure derived from NB, and a ring may have an alicyclic alkyl, alkylene or alkylidene substituent. The insertion reaction results in the formation of a unique propagating species more soluble in a polar than in a non-polar solvent and devoid of an available .beta.-hydrogen for termination. The ensuing propagation of a polymer chain proceeds without measurable unsaturation.

Abstract: The temperature of the polymerization medium of vinyl chloride with the involvement of oil-soluble initiators is controlled essentially by direct and modified injection of an effective amount of a strong inorganic inhibitor of radical polymerization or of a precursor advantageously chosen from iodine and nitrogen monoxide, as well as from alkali metal iodides and nitrites, which are the respective precursors of iodine and of nitrogen monoxide.

Abstract: A process for producing a monovinylidene aromatic polymer having molecular weight (Mw) greater than 275,000 which comprises polymerizing a monomer mixture comprising a monovinylidene aromatic monomer in the presence of:A) from 10 to 2000 ppm by weight of at least one free radical generating, branching polymerization initiator; andB) from 10 to 2000 ppm of one or more organic gel reduction agent selected from the group consisting of:1) mercaptans, terpenes, halocarbons and halohydrocarbons, such agent having up to 20 carbons,2) distillate recovered from the reaction devolatilization process (recycle), and3) mixtures of 1) and 2).

Abstract: Simultaneous control of the molecular weight and the molecular weight distribution in the production of toner resins can be accomplished by using a starve fed emulsion polymerization process, which includes: selecting a desired molecular weight and molecular weight distribution of the polymer resin; determining a starve fed fraction to achieve the desired molecular weight and molecular weight distribution; and charging a reaction vessel with a chain transfer agent and a first monomer emulsion, and polymerizing monomer in the first monomer emulsion while simultaneously adding to the reaction vessel additional monomer, in the form of a second monomer emulsion, and additional chain transfer agent. The resins thus produced may be used in dry toners, liquid developers and inks suitable, for example, for ink jet applications.

Abstract: This invention relates to a process for transitioning between incompatible polymerization catalyst systems. Particularly, the invention relates to a process for transitioning from an olefin polymerization reaction utilizing a traditional Ziegler-Natta catalyst system to a metallocene-olefin polymerization reaction.

Abstract: A process for preparing olefinic polymers by metallocene catalyzed olefin polymerisation in which at least one volatile catalyst kill agent is introduced. A non-volatile catalyst kill agent may also be used in conjunction with the volatile catalyst kill agent. Water may be used as the volatile agent and compounds containing a terminal hydroxy group, oxygen, nitrogen or sulfur may constitute the non-volatile agent. Purified monomer is recycled to the reactor.

Abstract: A method of terminating, under emergency conditions, an olefin polymerization reaction conducted in the presence of a transitioned metal based catalyst in a gas phase reactor by using a recycle gas from the reactor or a feed stream to the reactor to operate an expander associated with a circulator which maintains fluidized conditions in the reactor while introducing a kill gas into the reactor to terminate the reaction.

Abstract: A process for making a fluorinated copolymer is disclosed. The process comprises polymerizing a monomer to form a polymer and then terminating the polymerization by adding a perfluorinated alkyl chlorosilane to the polymer. The perfluorinated alkyl chlorosilane reacts with the polymer to form a copolymer having a fluorinated terminal portion thereon.

Abstract: The present invention relates to a process for stopping an olefin polymerization which is carried out in a low pressure gas phase reactor, which process comprises introducing an effective quantity of deactivating agent into the reactor, characterized in that the olefin polymerisation is carried out using a chromium oxide catalyst and in that the deactivating agent is selected from oxygen, ammonia, water and carbon monoxide and is introduced over a relatively short period of time. The deactivating agent is preferably introduced into the polymerization reactor in a quantity such that in the reactor the weight ratio of the deactivating agent to the catalyst is at least 0.001.