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: An saturated nitrile-conjugated diene copolymer obtained by copolymerizing acrylonitrile with butadiene in the presence of a free radical initiator and an alkylthiol compound as a molecular weight modifier. A part of the molecular weight modifier is incorporated in a monomer charge before polymerization, and the remainder thereof is incorporated in a polymerization mixture during polymerization. The alkylthiol compound has 12 to 16 carbon atoms, which include at least three tertiary carbon atoms, and further has a sulfur atom directly bound to at least one of the tertiary carbon atoms. The copolymer has a Mooney viscosity of 15 to 150 and contains 3 to 20 weight % of a fraction having a number average molecular weight of not larger than 35,000. The copolymer is used in combination with a sulfur-containing vulcanizer.

Abstract: Crystalline polychloroprene compositions comprise mercaptan-modified or xanthogen disulfide-modified 2-chloro-1,3-butadiene homopolymers having gel contents of 5-80 percent by weight. The polymers are prepared by free radical emulsion polymerization at a temperature of 5.degree.-20.degree. C. to a conversion of 70-95 percent in the presence of 2.5.times.10.sup.-4 -5.5.times.10.sup.-4 moles of mercaptan or xanthogen disulfide modifier per mole of 2-chloro-1,3-butadiene.

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: 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: Method for the shortstopping of polymerizations of conjugated dienes possibly mixed with vinyl-substituted aromatic products in a radicalic emulsion polymerization process using a redox initiator, in particular radicalic emulsion polymerizations of butadiene possibly mixed with styrene or acrylonitrile, a method which enables the production of polymers without nitrosamines (NA) and/or their precursors.

Abstract: A polymerizable composition containing;(A) 100 parts by weight of a vinylbenzyl compound of the formula (I), ##STR1## wherein each of R.sup.1 and R.sup.2 is independently a halogen atom, each of h and i is independently 0, 1 or 2, each of X.sup.1, X.sup.2 and X.sup.3 is independently an oxygen atom or a sulfur atom, and each of j, k and m is 0 or 1, provided that when k is 0, j is 0, that when m is 0, each of j and k is 0, that when j is 0 and when each of k and m is 1, X.sup.1 and X.sup.2 cannot be sulfur atoms at the same time, and that when each of m, k and j is 1, X.sup.1, X.sup.2 and X.sup.3 cannot be sulfur atoms at the same time,and(B) 0.1 to 20 parts by weight of 2,4-diphenyl-4-methyl-1-pentene.

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: A one-pot method of preparing sulfonic acid-terminated polyisobutylene by sulfonation with acetyl sulfate of living polyisobutylene in a single step. The method permits preparation of sulfonated telechelic polyisobutylenes (STPs) by "inifer" initiated carbocationic polymerization of isobutylene with Lewis acid to form a polymer, followed by the addition in the same reaction vessel of acetyl sulfate at the polymerization temperature or the decomposition temperature of the complex.

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: 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: There are provided a process for obtaining a polymer having hydroxyl groups at both terminals easily and with cheap cost and excellent efficiency from a wide variety of vinyl-based compounds, a composition containing said polymer and its use, and a polymer derived from said composition and its use.The polymerization reaction of a vinyl-based monomer (b) is carried out by using a radical polymerization initiator (c) in the presence of a compound (a) represented by the general formula:HO--A--(S).sub.x --B--OH (I)and, a polymer having hydroxyl groups at both terminals is obtained under conditions that, in the above reaction, any compound other than (a), (b) and (c) is not practically used and the compound (a) always exists in 50 mole times or more of the initiator (c) in the course of reaction in a reactor; and either a composition containing this polymer or a polymer derived from this composition is used.

Abstract: A process for emulsion polymerization to form a latex having a particle size greater than about 0.5 micrometers by charging to a reaction vessel under agitation a reaction mixture including water, emulsifiers at an initial concentration slightly greater than or equal to the critical micelle concentration, a protective colloid, ethylenically unsaturated monomers, and an ionically balanced combination of an anionic and a cationic water soluble free radical initiator or a nonionic initiator; reacting the mixture to form an emulsion of polymerized monomer; and adding additional monomer, emulsifier, and protective colloid and a water soluble chain transfer agent to the reactor while continuing to agitate the mixture under conditions such that the emulsifier concentration does not exceed that at which new polymeric nuclei are formed.

Abstract: Novel adhesive products are prepared by coating a novel adhesive formulation onto appropriate substrates. The adhesive formulation is capable of maintaining coatable viscosity at solids levels in excess of 58% and may comprise an interpolymer prepared in the presence of a high concentration of chain transfer agents, and may also comprise external and/or internal crosslinking agents. The Williams Plasticity Number of solids from the formulation may be less than 1.8 (determined in the absence of external crosslinking agents). Alkyl acrylamidoglycolate alkyl ether monomer copolymerized with a more reactive monomer provides an interpolymer having reduced need for strong acid catalysis.

Abstract: A process for shortstopping a free radical polymerization of a conjugated diene and optionally a vinyl-substituted aromatic in an aqueous emulsion, using a hydroperoxide as initiator and a redox activator, comprising a divalent transition metal, a reducing agent and optionally being carried out in the presence of a modifier, and being performed by using as sole shortstopping agent an alkali metal polysulphide. This process results in the production of polymeric products which are free of carcinogenic nitrosamines.

Abstract: A process for preparing a vinyl chloride polymer, which comprises polymerizing vinyl chloride or a monomeric mixture composed mainly of vinyl chloride in an aqueous medium, wherein the polymerization reaction is terminated at the last stage of polymerization by addition of an aqueous dispersion of an antioxidant, containing a polyoxyalkylene glycol as a dispersing agent. A polymer with good initial coloration characteristic, thermal stability and take-up of plasticizer, and large bulk density can be obtained.

Abstract: A chloroprene polymer having dithiocarbamate groups at both terminals, represented by the following formula (I): ##STR1## wherein M.sub.1 is a chloroprene monomer residue; X is a group represented by the following formula (II): ##STR2## wherein R.sub.1 is a C.sub.1 -C.sub.8 alkyl group, R.sub.2 is a C.sub.1 -C.sub.8 alkyl group or a hydrogen atom, R.sub.1 and R.sub.2 may be the same or different, or R.sub.1 and R.sub.2 together form a C.sub.3 -C.sub.8 methylene group so that they form a cyclic group together with the adjacent nitrogen atom, or a group represented by the following formula (III): ##STR3## wherein R.sub.1 is a C.sub.1 -C.sub.8 alkyl group, and R.sub.2 is a C.sub.1 -C.sub.8 alkyl group or a hydrogen atom; and n is a natural number of from 10 to 5,000 when X is the group of the formula (II) or a natural number of form 5 to 100 when X is the group of the formula (III).

Abstract: A process for the continuous polymerization of one or more alpha-olefins with a transition metal catalyst, in a reactor having a fluidized and/or mechanically stirred bed, in which a very small amount of an activity retarder, generally less than 0.1 ppm, is introduced continuously into the reactor at a flow rate which is varied with time so as to keep substantially constant either the polymerization rate or the content of transition metal in the polymer produced. Suitable activity retarders include polymerization inhibitors such as, for example, oxygen, alcohols, carbon monoxide and carbon dioxide and electron donor compounds such as amides and ethers.

Abstract: A process for manufacturing a polymer includes the first step of reacting a solution of one of two starting materials in an organic solvent with the other material in the form of a powder, and the second step of reacting a solution of the reaction product of the first step in an organic solvent with a solution of the other material in an organic solvent. The process preferably includes one or both of two additional steps, i.e. filtering the reaction product of the first step, and degassing the reaction product of the second step by stirring it at a reduced pressure. An apparatus for carrying out the process is also disclosed. This invention makes it possible to produce a polymer of high and uniform quality having a final viscosity controlled within a certain range and not containing foreign matter or bubbles.

Abstract: A conjugated diene copolymer comprising (A) 40 to 90 mole % of a conjugated diene component, (B) 0.5 to 10 mole % of an alpha,beta-ethylenically unsaturated carboxylic acid component, (C) 0.1 to 5 mole % of a polyfunctional alkenyl compound component and (D) 5 to 58 mole % of a monoolefinically unsaturated compound component wherein the intrinsic viscosity [.eta.] of the copolymer as measured at 30.degree. C. in dimethylformamide is 0.01 to 3.0 dl/g, the width (.DELTA.Tg) of the endothermic transition temperature section determined by a differential scanning calorimetry is 45.degree. to 120.degree. C., and the limit temperature (T.sub.1) on the lower temperature side of the endothermic transition temperature section is -40.degree. C. or less.

Abstract: Coupling agents of general formula ##STR1## and their use in a method for the termination of living polymers obtained by anionic polymerization of diene and/or vinylaromatic monomers.

Abstract: In a process for the mass polymerization of vinyl aromatic monomer wherein vinyl aromatic monomer is polymerized in successive stages of increasing temperature, the improvement which narrows the molecular weight distribution of the resulting polymer comprising incorporating a polymerization inhibiting agent into a polymerizing mass at a point where about 60 to about 95% of monomer is converted to polymer.

Abstract: An improved method of terminating ethylene polymerization and interpolymerization reactions by deactivating the Ziegler-type catalyst used in the reaction comprises the step of injecting a selected deactivating agent into the molten polymer solution in the polymerization reactor prior to degassing of the polymer solution.The deactivating agent is selected from the group consisting of:(a) natural hydrotalcite minerals and synthetic hydrotalcite-like materials;(b) Group IIIA metal salts of monocarboxylic acids;(c) alkali metal and alkaline earth metal salts of alkarylsulfonic acids;(d) alkali metal and alkaline earth metal salts of alkyl and alkaryl sulfuric acids;(e) organophosphites of a formula selected from the group consisting of (RO).sub.3 P and (RO).sub.2 POH where R is a hydrocarbon group containing 1 to 22 carbon atoms, inclusive;(f) ethoxylated hydrocarbylamines of the formula R'.sub.3-n N[(OCH.sub.2 CH.sub.2).sub.m OH].sub.

Abstract: An improved process for terminating the suspension polymerization reaction of vinyl chloride monomer into polyvinyl chloride which comprises adding hindered phenols of the structure presented hereinafter to the polymerization reaction at a point in time when a predetermined amount of monomer conversion has occurred.

Abstract: A compound and a process for utilizing the compound to prevent the polymerization of vinyl aromatic compounds, such as styrene, during heating. The composition includes effective amounts of 2,6-dinitro-p-cresol and either a phenylenediamine or 4-tert-butylcatechol respectively, to act as a polymerization co-inhibitor system in the presence of oxygen.

Abstract: A compound and a process for utilizing the compound to prevent the polymerization of vinyl aromatic compounds, such as styrene, during heating. The compound includes effective amounts of phenothiazine, 4-tert-butylcatechol and 2,6-dinitro-p-cresol respectively, as a polymerization inhibitor system in the presence of oxygen resulting in a less viscous polymer tar and in the effective inhibition of polymerization to temperatures as high as 150.degree. C.

Abstract: A compound and a process for utilizing the compound to prevent the polymerization of vinyl aromatic compounds, such as styrene, during heating. The composition includes effective amounts of 2,6-dinitro-p-cresol and either a phenylenediamine or 4-tert-butylcatechol respectively, to act as a polymerization co-inhibitor system in the presence of oxygen.

Abstract: A process is described for the production of copolymers derived predominantly from a monomer, e.g. tert-butylstyrene, having a very low solubility in water, by low temperature emulsion polymerization in a medium consisting substantially of water alone, under specified reaction conditions; high levels of conversion of monomer are achieved. The copolymer products are useful as additives to liquid hydrocarbon fuels for the purpose of reducing the tendency of the fuels to disseminate into mists under conditions of shock.

Abstract: By adding substances corresponding to the following general formula I ##STR1## in which X=O, S or N--R.sub.5 ; R.sub.1 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.2 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.12 -alkenyl, phenyl or C.sub.1 -C.sub.4 -alkylene phenyl; R.sub.3 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl formyl or acetyl; R.sub.4 and R.sub.5 =same or different, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.4 and R.sub.5 may also form a C.sub.4 -C.sub.7 -ring which may optionally contain an oxygen atom in ether form and the radicals R.sub.1 and R.sub.2 may form a C.sub.5 -C.sub.12 -alkylene bridge or a C.sub.5 -C.sub.12 -alkenylene bridge, the radicals R.sub.

Abstract: A heat-stable, polymer-forming composition of a polymerizable material, a transition metal compound, a polymer chain terminator, and, optionally, a preventive antioxidant is disclosed as well as particular uses of such composition.

Abstract: Process for rapidly terminating the polymerization of vinyl chloride in aqueous suspension in the presence of lower dialkyl peroxydicarbonates by introducing effective amounts of ammonium hydroxide and an alkali metal thiosulphate, e.g. sodium or ammonium thiosulphate, into the polymerization medium. This process enables polymerization to be quickly and effectively terminated when a breakdown occurs.

Abstract: An acrylic resin having an intrinsic viscosity [.eta.] of about 0.028 to about 0.117 l/g and a weight-average molecular weight to number-average molecular weight ratio (Mw/Mn), measured by gel permeation chromatography of about 2.3 to about 6.0, said resin comprising the polymerization product of (1) about 50 to 100 wt. % of methyl methacrylate and (2) 0 to about 50 wt. % of at least one monomer selected from the group consisting of acrylic ester monomer and methacrylic ester monomer, said acrylic ester monomer comprising the reaction product of an alkyl alcohol having 1 to 8 carbon atoms and acrylic acid and said methacrylic ester comprising the reaction product of an alkyl alcohol having 2 to 12 carbon atoms and methacrylic acid.

Abstract: The present invention relates to the polymerization of vinyl monomers either alone or copolymerized with ethylenically unsaturated polymerizable monomers having a terminal CH.sub.2 .dbd.C< grouping using a free-radical yielding catalyst or catalyst system, wherein the polymerization reaction is effectively stopped by the addition to the reaction mixture of a shortstopping agent, such as, for example, 4,4'-thiodiphenol (TDP).

Abstract: Small particles of cellulose-containing plants and an oxidated silicon compound are mixed with an alkali metal hydroxide then heated to 150.degree. to 220.degree. C. while agitating thereby producing an alkali metal broken down lignin-cellulose silicate polymer which is then reacted with a polysubstituted organic compound to produce a broken down lignin-cellulose silicate copolymer.

Abstract: This invention relates to a process for preparing polyisocyanate silicate plastics by reaction of an alkali metal cellulose silicate condensation product with a compound having at least two isocyanate groups to produce a polyisocyanate silicate prepolymer. The prepolymer is then reacted with an organic compound to produce a polyisocyanate silicate plastic.

Abstract: What is disclosed is a method for the partial polymerization of at least one vinyl monomer to form a mixture of said monomer with a polymer thereof, which comprises initiating polymerization of said monomer with a percarbonic acid ester and inhibiting further polymerization when the desired mixture is formed by addition thereto of a thioether, an organic disulfide, or a mercaptan, as are the partially-polymerized mixtures so produced, and their use for forming an organic glass by further polymerization thereof.

Abstract: Small particles of cellulose-containing plants, fine granular oxidated silicon compounds and an alkali metal hydroxide are mixed, then heated to 150.degree. C. to 220.degree. C. while agitating until the plant particles soften or melt, thereby producing an alkali metal cellulose silicate condensation product.

Abstract: Vapor phase polymerization of an olefin which comprises conveying inactive high yield titanium catalyst component to a vapor phase polymerization reactor with a liquid comprising recycled quench liquid, reactivating said inactive high yield titanium catalyst component inside the reactor with a metal alkyl reducing agent and polymerizing olefin under gas phase polymerization conditions with reactivated high yield catalyst to form a resinous polymer of an olefin having a low level of catalyst residues.

Abstract: Esters of acrylic acid and methacrylic acid may be polymerized with the aid of either free radical forming or ionically effective initiators. The stereospecificy of the polymers may be influenced by the selection of specific initiators; magnesium-organic compounds are suitable for the synthesis of isotactic polymers. Acrylic acid and methacrylic acid esters having a high degree of isotacticity and a narrow molecular weight distribution are obtained with the aid of substituted phenylmagnesium halides. They are suitable as gauge and as test substances.

Abstract: A graft copolymer is provided which is characterized by excellent gas impermeability, transparency and impact strength, as well as good flowability, and hence good molding workability, by copolymerizing an olefinically unsaturated nitrile with an alkyl vinyl ether in the presence of a rubbery polymer, which contains at least 50% by weight of a conjugated diene; said olefinically unsaturated nitrile being present in an amount of from 60 to 95% by weight, based on the total weight of said olefinically unsaturated nitrile and said alkyl vinyl ether; and wherein said olefinically unsaturated nitrile and said alkyl ether are present in an amount of from 3 to 50 times by weight the quantity of said rubbery polymer.

Abstract: Organic reinforcing fillers for rubber are prepared by the anionic initiated slurry polymerization of styrene and divinylbenzene in the presence of a block polymer dispersant. The polymerization reaction may be carried out using, as the anionic initiator, an alkali metal-bearing compound capable of initiating polymerization of styrene without imparting to the polymerization product groups reactive with rubber in a rubber cure in which case the polymerization is terminated by reaction of the polymer particles with a terminating agent that provides in the polymer groups reactive with rubber in a normal rubber cure; or the polymerization reaction can be carried out using, as the initiator, an alkali metal-bearing unsaturated polymer that in itself imparts to the polymer groups reactive with rubber in a normal rubber cure.

Abstract: Low molecular weight polymers of ethylenically unsaturated monomers are prepared by a bulk polymerization process using organic mercaptans as the polymerization catalysts and carried out in the presence of oxygen. These low molecular weight polymers find utility as high solids casting and coating resins.

Abstract: A process for preparing polymeric compositions having low permeability to gases and which are particularly useful in the packaging industry wherein said polymers are prepared from rubber-modified copolymers of an olefinically unsaturated nitrile monomer and a vinyl aromatic monomer using tertiary butyl mercaptan as a chain transfer agent in the polymerization reaction.