Abstract: Block copolymers and the processes of preparing them are disclosed wherein alpha-olefins and/or mixtures of alpha-olefins are alternately polymerized in the presence of a catalyst comprising a titanium halide and an aluminum alkyl compound.

Abstract: Radiation cross-linkable compositions comprising a copolymer of ethylene and a halogenated monomer selected from the group consisting of chlorotrifluoroethylene, tetrafluoroethylene and mixtures thereof and an effective amount of a radiation cross-linking agent selected from the group consisting of diallyl isophthalate, diallyl terephthalate and mixtures thereof.

Abstract: A modified elastomer having a phenolic hydroxyl group on the side chain which is excellent in tackiness and in compatibility with other elastomers, characterized in that the elastomer is obtained by graft-copolymerizing an elastomer, prepared by copolymerizing ethylene with at least one .alpha.-olefin represented by the general formula R'--CH=CH.sub.2, wherein R' is an alkyl group, and at least one non-conjugated diene or polyene, with at least one phenolic monomer represented by the general formula (A), ##STR1## wherein R is a lower alkyl group or a hydrogen atom; and R.sub.1 to R.sub.5 are individually an alkyl group, a hydrogen atom or a hydroxyl group, one of said R.sub.1 to R.sub.5 being a hydroxyl group, and wherein the said hydroxyl group may have been protected by an alkyl, acyl or the like group.

Abstract: A novel copolymer is obtained by reacting [A] at least one norbornene derivative having at least one polar group or polar-group-containing substituent with [B] at least one unsaturated polymer having carbon-to-carbon double bonds in the presence of a metathesis catalyst. This copolymer is excellent in chemical and mechanical properties. Particularly, when 50% by weight or more of the component [A] is contained, the resin is distinguished for its high impact strength.

Abstract: In the aqueous polymerization of vinyl chloride and vinylidene chloride polymers and copolymers in reactors having exposed metal surfaces, undesirable thin polymer build up is noted on the metal surface exposed to the polymerization media. Such polymer build up is substantially reduced if before the polymerization the reactor is first mechanically cleaned to remove visible polymer deposits and then cleaned of organic materials adsorbed on the metal surfaces; and thereafter between polymerization charges as required, by treatment with a hot-alkali detergent mixture to remove organic residues from the surface of said metal surfaces.

Abstract: A process for the manufacture of olefin polymers by polymerization of .alpha.-monoolefins by means of a silicic acid xerogel/chromium trioxide catalyst, which is obtained by a method wherein (1) a finely divided silicic acid xerogel is first manufactured by (1.1) employing a silicic acid hydrogel of relatively high solids content, (1.2) extracting at least 60% of the water contained in the hydrogel from the latter by means of a particular organic liquid, (1.3) drying the gel thus obtained until there is no further loss in weight (xerogel formation) and (1.4) reducing the xerogel thus obtained to particles of diameter from 20 to 2,000 .mu.m,2. this xerogel is then charged with the desired amount of chromium from a solution of chromium trioxide or a solution of a chromium compound which under the conditions of stage (3) is converted to chromium trioxide, with evaporation of the solvent, and3. finally the product thus obtained is heated in an anhydrous stream of gas containing oxygen.

Abstract: A two-step process comprises (A) polymerizing ethylene in the presence of a catalyst comprising (1) at least one organoaluminum compound, (2) at least one titanium tetrahalide and (3) optionally, at least one Lewis base, and (B) thereafter polymerizing isoprene in the presence of the step (A) reaction mixture. The reaction product contains polymerized therein about 0.05 to about 2.2 weight percent ethylene. The reaction product has satisfactory green strength and monomer conversion efficiency together with excellent processability.

Abstract: The polymerization of olefins to form polymers having a molecular weight greater than 50,000 wherein the polymerization is carried out in the presence of a catalyst component formed of a compound of a transition metal of the sub-groups IVa, Va and VIa, and a co-catalyst component of at least one organo-metallic compound of a metal from groups II and III of the periodic table, in which the co-catalyst is in the form of a liquid which is separately introduced into the reaction vessel on a carrier formed of an inert porous powder which is impregnated with the co-catalyst.

Abstract: Compounds having at least one olefinic unsaturation (e.g. isoprene) are polymerized in the presence of a catalyst system consisting of a transition metal compound such as TiCl.sub.4 and an aluminum hydride derivative which is either (a) an oligomer N-alkylaminoalane of the type: ##STR1## or (b) an oligomer derivative having the general formula:(XAlNR).sub.x (XYAl).sub.y (NHR).sub.y.

Abstract: A catalyst system for the polymerization of at least one 1-olefin to produce a polymer of ultralow molecular weight (ULMW) and prepared by (1) forming a substantially dry intimate mixture of an alkyl ester of titanium containing about 1-7 carbon atoms in the alkyl group and a support of the class consisting of finely divided silica, alumina, zirconia, thoria and mixtures thereof, (2) calcining said ester-support mixture to and at a temperature between about 400.degree.-1000.degree. C., (3) adding to the resulting calcined mixture an organotin chromate essentially of the formula ##STR1## wherein each R is an individually selected hydrocarbon radical containing from 1-14 carbon atoms, and (4) activating the resulting coated calcined mixture by heating to and at a temperature between about 300.degree.-500.degree. C. in the presence of oxygen.

Abstract: High molecular weight polymers and highly unsaturated polymers (e.g. butyl rubber) are prepared by homopolymerizing and copolymerizing olefins, isoolefins, conjugated multiolefins, or mixtures of isoolefins and conjugated multiolefins with a catalyst system comprising an organoaluminum compound in conjunction with a cocatalyst selected from the group consisting of sulfur dioxide, sulfur trioxide, halogens, mixed halogens and hypohalides.

Abstract: A melt phase process for the preparation of emulsifiable polyethylene waxes by reacting polyethylene waxes with an unsaturated polycarboxylic component in the presence of a free radical source in the substantial absence of oxygen.

Abstract: Block copolymers of (i) a polymer of ethylene or propylene, or copolymer of ethylene or propylene with another .alpha.-olefin and (ii) a polymer of an acrylic ester or a methacrylic ester are formed by polymerizing (i) in the presence of a titanium halide and an organic aluminum compound, and then adding in order (a), (b) and (c) to copolymerize a product so obtained with (a) an acrylic ester or a methacrylic ester, in the presence of (b) an organic phosphorus compound or tertiary amine and (c) a benzyl halide, a ring-alkylated benzyl halide, a benzyl halide in which a methylene hydrogen is replaced with an alkyl or aryl group, or an alkyl halide.

Abstract: A continuous process is disclosed for manufacturing a grafted polymeric material of improved quality. The process is conducted in baffled tubular reactors which exhibit dispersed plug-flow character and which provide: rapid heating and cooling of reactants; short reaction time with uniform material residence time; and radial uniformity of temperature.

Abstract: In apparatus for polymerizing high-pressure ethylene to produce polyethylene, a tubular reactor is connected to a source of solution to the tubular reactor. This solution includes one or more catalysts which promote the polymerization reaction. Within the tubular reactor, a peak temperature occurs in proximity of the point at which the catalysts are introduced. If the catalysts are introduced at more than one point, peak temperatures will result downstream of each of such points. For various reasons, the peak temperatures are displaced along the tubular reactor and a plurality of thermocouples are distributed at spaced positions in the tubular reactor to measure the temperatures at the positions at which the peak temperature might occur. These thermocouples generate signals which are fed into a gating arrangement which selects the peak signal which is compared in a comparator circuit with an adjustable or selectable signal representative of the peak temperature which is desired.

Abstract: Ethylene homopolymers and copolymers are made in a particle form process over a mixed catalyst comprising several portions of the same or different supported chromium components and metal promoted variations thereof in which each portion is activated at a different temperature, thereafter combined, and the composite, or each activated portion before being combined, is post treated with a hydrocarbyl aluminum hydrocarbyloxide. Broad molecular weight polymers are produced having excellent die swell characteristics and acceptable environmental stress cracking resistance and flow properties; this is achieved and while at the same time realizing high productivities.

Abstract: The residence time of material within a vessel having an inlet, an outlet, and conveyor means for moving material from the inlet to the outlet is controlled in response to the level of material within the vessel adjacent the input stream to the vessel, the level of material within the vessel adjacent the output stream leaving the vessel, and the rate at which material is flowing from the vessel. The speed at which material is conveyed from the inlet of the vessel to the outlet thereof is controlled in response to the flow rate of material leaving the vessel, the level of material adjacent the outlet of the vessel, and the desired residence time of material within the vessel. The flow rate of material to the vessel is controlled in response to the amount of material leaving the vessel, the level of material adjacent the inlet of the vessel, and the desired residence time of material within the vessel.

Abstract: Disclosed are chlorinated low unsaturation rubbers exhibiting improved adhesion properties and improved covulcanization ability with high unsaturation rubbers. Also disclosed is a method of preparing these rubbers which comprises reacting the chlorinated rubber with certain bromine and/or iodine containing compounds.

Abstract: The method of this invention is particularly useful for removing heat from an exothermic reaction of a liquid medium. An example of such a reaction is an emulsion polymerization of styrene and butadiene to obtain a latex product. In this reaction the butadiene will boil at the temperature and pressure conditions in the reactor. Attached to the reactor is a condenser unit, which is basically a modified shell and tube heat exchanger. During the reaction the butadiene vapors are directed from the reactor into the tube bundle of the condenser unit through the top of the unit. In the condenser the butadiene vapors are condensed to a liquid, which flows downwardly into the reactor to cool the reaction mass.

Abstract: There is disclosed a method of preparing high cis-1,4-polybutadiene which comprises continuously polymerizing butadiene in mixture with an inert aliphatic or cycloaliphatic solvent employing as a catalyst a mixture comprising (A) at least one trialkyl aluminum wherein the alkyl group contains from 2 to 8 carbon atoms, (B) at least one nickel salt of carboxylic acids and (C) at least one boron trifluoride complex of ethers in which each of the individual catalyst components are continuously injected into the polymerization vessel containing the mixture of butadiene and inert solvent.