Abstract: Spherical polymer particles have at least two peaks, or have at least one peak and a shoulder formed on the high-molecular weight side with respect to the peak, in their chromatogram obtained by gel permeation chromatography. The spherical polymer particles can turn into a viscoelastic form in a broad temperature range, and promise a superior heat fixing performance of toner images especially when used as image forming toner.

Abstract: The present invention is an improved method for making fiber polymer optical fiber cable and graded index optical fibers. The polymer can be any shape including, but not limited to sheets, films or cable. The present invention also includes improved polymer optical fibers that incorporate compositions that shift the wavelength of radiation from ultraviolet radiation or X-ray radiation or infrared radiation to visible radiation.

Abstract: Highly flexible propylene/ethylene copolymers having a high rubber content are obtainable by two-stage polymerization from the gas phase in an agitated fixed bed by means of a Ziegler-Natta catalyst system which, in addition to a titanium-containing solid component, also contains an aluminum compound as a cocatalyst, in a first polymerization stage, propylene being polymerized at from 15 to 40 bar and from 50.degree. to 90.degree. C. and during an average residence time of the reaction mixture of from 0.5 to 5 hours and then, in a second polymerization stage, a mixture of propylene and ethylene being polymerized with the polymer discharged from the first polymerization stage, at from 5 to 30 bar, this pressure being at least 2 bar below the pressure of the first polymerization stage, and at from 60.degree. to 100.degree. C. and during an average residence time of the reaction mixture of from 0.

Abstract: A continuous process is disclosed for producing a strip of decorated ski coating material from ultra-high molecular weight polyethylene. A 0.5 to 1.5 mm thick strip of ski coating material produced in a screw-type or piston-type extruding machine or by sintering followed by peeling and printed with thermodiffusion dyes continuously runs through a heating zone in which it is uniformly heated up to a temperature above 140.degree. C., so that the crystalline structure of the ultra-high molecular weight polyethylene is partially decomposed and the thermodiffusion dye diffuses into the molten ski coating material without the need for an intermediate carrier.

Abstract: A method is provided for the production of a water-soluble or water-dispersible copolymer. The copolymer is comprised of a water-soluble base monomer and/or a water-soluble or water-dispersible macromer. The disclosed method involves a two step polymerization procedure wherein in a first step a minor portion of the reactants are polymerized to conversion under conditions which result in the formation of a low molecular weight product, and in a second step the remaining portion of the reactants are polymerized to conversion in the presence of the reaction product of the first step under conditions which result in the production of a higher molecular weight product.

Abstract: Microcapsules which are composed of a core and of a shell of a polymer, the core containing at least one oil which can be emulsified in water, and which are obtainable by polymerization of oil-soluble monomer mixtures which contain(a) 1-100% by weight of acrylic anhydride, methacryic anhydride, itaconic anhydride, citraconic anhydride, dimethylmaleic anhydride, 4-vinylbenzoic anhydride, mixed carboxylic anhydrides, mixtures of the said anhydrides and/or more than 40% by weight of maleic anhydride,(b) 0-99% by weight of at least one monoethylenically unsaturated monomer which is different from the monomers of group (a),(c) 0-80% by weight of crosslinking monomers which have at least two monoethylenically unsaturated non-conjugated double bonds in the molecule, and(d) 0-20% by weight of water-soluble monoethylenically unsaturated monomersin the oil phase of a stable oil-in-water emulsion in the presence of polymerization initiators which form free radicals, where the temperature of the polymerizing reaction mix

Abstract: The invention comprise a composition for breaking oil-in-water emulsions comprising adding from about 1 part per million to about 500 parts per million of an amphoteric acrylic acid copolymer to the emulsion. Once the copolymer is added, the emulsion is subjected to agitation until the oil-in-water emulsion is resolved and the oil and water separates into two phases. The oil and water phases are then subjected to a separation technique to separate the phases. The invention further comprises a method of synthesizing the amphoteric polymers used in the emulsion breaking application.

Abstract: An absorbent resin exhibiting a high absorption ratio, having only a small water-soluble component content, and have excellent gel stability to withstand the effect of aging is produced. The production of the absorbent resin comprises a step of polymerizing a water-soluble monoethylenically unsaturated monomer by using, in a proportion of 0.01-0.3 mol % based on the amount of the water-soluble monoethylenically unsaturated monomer, a cross-linking agent having at least one group of the following formula I: ##STR1## wherein R.sup.1 is an alkylene group of 2 to 4 carbon atoms interposed between two polymerizing unsaturated groups in the molecular unit thereof and then heat-treating the resin produced by the polymerization at a temperature in the range of from 160.degree. to 230.degree. C.

Abstract: This invention discloses a process for preparing a latex which is particularly beneficial for utilization in manufacturing high performance masking tape, which includes the sequential steps of (1) terpolymerizing a vinyl aromatic monomer, an alkyl acrylate monomer, and an alkyl propenoic acid monomer in an aqueous polymerization medium by free radical polymerization to produce a seed polymer latex; (2) neutralizing the seed polymer latex to a pH of about 6 to about 9 by the addition of an alkali; (3) adding additional vinyl aromatic monomer and alkyl acrylate monomer to the neutralized seed polymer latex; and (4) allowing the additional vinyl aromatic monomer and alkyl acrylate monomer to polymerize in a second polymerization step to a solids content of about 30% to about 50% to produce the latex which is particularly beneficial for utilization in manufacturing high performance masking tape.

Abstract: A process for the preparation of an ethylenic polymer composition having excellent physical properties such as high impact properties, environmental stress cracking resistance, pinch-off fusing characteristics and having an intrinsic viscosity ranging from 3.2 to 4.5 dl/g and a density ranging from 0.943 g/cm.sup.3 to 0.958 g/cm.sup.3.

Abstract: The invention concerns a process for manufacturing a strip of ski-coating material made of polyethylene of ultra high molecular weight, wherein a ski-coating strip material 4 manufactured to a thickness of 0.5 to 1.5 mm by a screw extruder, a ram extruder or press sintering with subsequent peeling is made to pass continuously first through a heating zone 1 in which it is heated to temperature above 140.degree. C. and then through a cooling zone consisting of two sizing plates 2, 2' in which it is cooled to a temperature equal to or lower than ambient. This process produces a ski coating of which the crystalline proportion can be adjusted within a range of 25 and 60%, as a result of which improved gliding by the ski coating on snow and improved wax acceptance is assured in comparison with the known methods.

Abstract: Disclosed are a styrene copolymer having a weight average molecular weight of about 200,000 to 2,000,000, having 1 to 20 branching points in the Z-average molecular weight, and having a methyl ethyl ketone/methanol mixture-insoluble matter content of not more than 5% by weight and a methanol-soluble matter content of not more than 5% by weight; processes for preparing the styrene copolymer; a polystyrene resin composition containing the styrene copolymer; and injection-molded article prepared by injection-molding the polystyrene resin composition.

Abstract: A continuous process for the solution polymerization of appropriate polycycloolefins in a ROMP zone to obtain a processable ROMP homo- or copolymer in solution, and subsequent hydrogenation of the ROMP (co)polymer without removing the residual ROMP catalyst and co-catalyst, provides an optical product having a mol wt M.sub.w in the range from 50,000-300,000 and polydispersity M.sub.w /M.sub.n in the range from 1.3-5.0, more preferably from 1.3-3, the lower the polydispersity the more desirable the physical properties of the (co)polymer.

Abstract: A process for suspension polymerization of tetrafluoroethylene to polytetrafluoroethylene is characterized by starting reaction at low temperature and increasing temperature to higher temperature during the reaction.

Abstract: A process for preparing copolymers of ethylene with acrylic esters by copolymerizing 100 parts by weight of ethylene with from 0.1 to 25.0 parts by weight of acrylic ester in a continuous tubular polymerization system at from 500 to 4000 bar and from 100.degree. to 400.degree. C. in the presence of free radical polymerization initiators, comprises controlling the temperature for the reaction mixture, comprising ethylene, the acrylic ester, the polymerization initiator and optionally a regulator, after entry into the reaction zone in such a way that the ratio dT/dt (temperature increase per unit time) is kept constant at a value within the range from 1.5.degree. to 2.5.degree. C. per second.

Abstract: A hydrophobic polyelectrolyte copolymer which is useful in the removal of color in paper mill waste water. The copolymer preferably comprises diallyldimethylammonium chloride and a hydrophobic monomer selected from the group consisting of quaternized dimethylaminoethylacrylates and quaternized dimethylaminoethylmethacrylates.

Abstract: This invention relates to an improved process for producing a clear solution of vinylpyrrolidone (VP) and vinyl acetate (VA) monomers which comprises, in an anhydrous system,(a) reacting a C.sub.2 to C.sub.3 alcoholic solution containing said VA monomer and between about 60 and about 80 wt. % portion of total VP monomer in the presence of between about 0.05 and about 0.3 wt. % of a free radical initiator selected from the group consisting of tertamylperoxy pivalate and 2,2-azobis(2-methylbutyronitrile) or a mixture thereof for a period of from about 5 to about 10 hours, at a temperature between about 60.degree. and about 110.degree. C.;(b) gradually adding the remaining VP monomer in C.sub.2 to C.sub.3 alcohol solution at reaction temperature after the addition of the VA monomer is complete;(c) raising the temperature of the resulting reaction mixture to between about 110.degree. and about 150.degree. C.;(d) continuing the polymerization reaction at said higher temperature in the presence of from about 0.

Abstract: Polyolefin rubber which is an ethylene/propylene and/or 1-butene copolymer, which has a melt index of 0.3 to 15 dg/min and a relative density of 0.860 to 0.885, comprising 74-91 mol % of units derived from ethylene and 9-26 mol % of units derived from propylene and/or from 1-butene, characterised by a crystalline melting point J of 100.degree. to 125.degree. C. The process for obtaining this rubber consists in copolymerising, at a temperature of 150.degree.-300.degree. C. and at a pressure of 400-2000 bars, a gas stream containing 15-42% by vol. of ethylene and 58-85% by vol. of propylene and/or 1-butene, in the presence of a Ziegler-type catalyst system comprising at least one compound of a transition metal of groups IVB, VB, VIB and VIII of the Periodic Classification, and at least one organoaluminium compound and, if appropriate, in the presence of at least one chain transfer agent.

Abstract: The processes for producing highly water absorptive resins of the present invention comprise the following steps: (A) suspending an aqueous solution of partially neutralized alkali metal acrylate and optionally partially neutralized acrylamido alkane sulfonate in a hydrocarbon solvent containing a surfactant having a HLB value of 3.apprxeq.6 or 8.apprxeq.

Abstract: Microcapsules useful for producing pressure-sensitive recording materials are obtainable by polymerizingA) 30-100% by weight of one or more C.sub.1 -C.sub.24 -alkyl esters of acrylic or methacrylic acid (monomers I),B) 0-80% by weight of a bi- or polyfunctional monomer (monomer II) which is soluble in a solvent which is insoluble or only sparingly soluble in water, andC) 0-40% by weight of other monomers (monomers III),the solvent being present alone or together with the monomers and a free radical initiator as the disperse phase of a stable oil-in-water emulsion and the polymerization being initiated and controlled by the thermal decomposition of the free radical initiator.

Abstract: A styrene, isoprene, butadiene terpolymer rubber with a characterization according to its glass transition temperatures and unit structure and a pneumatic tire with a tread composed of such terpolymer rubber specifically in combination with selected other rubber.

Abstract: The present invention provides a process for polymerizing diallyldialkyl ammonium compounds to produce polymers with increased molecular weight in which the polymerization is carried out in an aqueous medium containing an inorganic salt and a water soluble free radical initiator that does not react with the inorganic salt or a counterion of the diallyldialkyl ammonium compound to form a chain transfer or chain terminating agent.

Abstract: A novel styrene type resin having excellent strength which comprises(A) a unit represented by the formula ##STR1## wherein l and n are each an integer of 1 to 20;m is an integer 0 to 5; andR.sub.1, R.sub.2, R.sub.3 and R.sub.4 are each a hydrogen atom, an alkyl group having 1 to 5 carbon atoms, a cyclohexyl group or a phenyl groupand(B) a unit represented by the formula ##STR2## wherein R.sub.1 is a hydrogen atom or a methyl group andR.sub.2 is a hydrogen atom or an alkyl group having 1 to 5 carbon atomsand wherein the ratio of S.sub.A (namely, an amount of structural unit (A)) to S.sub.B (namely, an amount of structural unit (B)), S.sub.A /S.sub.B, is in the range of 0.00001 to 0.006; the resin having weight average molecular weight in the range of 200,000 to 600,000; and a total amount of styrene type monomers, styrene type dimers, styrene type trimers and a solvent of not more than 0.8% by weight.

Abstract: An extrusion polymerization process is described in which the polymerization of vinylic monomers, in particular acrylic monomers, is carried out in bulk in an extruder. The polymerization reaction is catalysed by a catalyst composition comprising an initiator, e.g. a ureido substituted silane, and a co-catalyst which is a salt providing a source of anions, e.g. fluoride ions.

Abstract: An improved process for the production of a water-absorbent resin by reversed phase suspension polymerization of a water-soluble ethylenic unsaturated monomer is disclosed. The process is conducted by subjecting an aqueous solution of a water-soluble ethylenic unsaturated monomer to reversed phase suspension polymerization reaction of a first stage in a petroleum hydrocarbon solvent in the presence of a surfactant and/or polymeric protective colloid by using a radical polymerization initiator optionally in the presence of a crosslinking agent, cooling the resulting slurry to precipitate the surfactant and/or polymeric protective colloid, and adding an aqueous solution of a water-soluble ethylenic unsaturated monomer containing a radical polymerization initiator and optionally a crosslinking agent to the first polymerization reaction system to further carry out the reversed phase suspension polymerization reaction, at least, once.

Abstract: A suspension polymerization process for the preparation of a polymeric material formed from at least two monomers, a non-gaseous monomer and a gaseous monomer. The composition of the beads or particles of the polymeric material is controlled by adding gaseous monomer to the vapor phase after polymerization of about 5% to about 90% by weight of the non-gaseous monomer or by removing a portion or substantially all of the gaseous monomer in the vapor phase before polymerization of about 70% by weight of the gaseous monomer in the aqueous suspension, or a combination thereof.

Abstract: The invention relates to a process for preparing polymers, with a polydispersity optionally approaching the theoretical polydispersity and substituted by functional groups in .alpha.,.omega.-positions, via radical polymerization of radically polymerizable monomers and using one or more initiators. In compliance with this process the degree of polymerization is maintained at the desired value by continuous elevation of the temperature.In case of a given heat program, the process of the invention renders possible to increase the conversion in producing polymers without the deterioration of the polydispersity.

Abstract: A process for preparing a blend of a norbornene polymer and a vinyl polymer, the process comprising (a) injecting into a mold a reaction mixture comprising from about 30 to about 70 weight percent, based on the total monomer weight, of at least one substituted or unsubstituted norbornene monomer, from about 70 to about 30 weight percent of at least one polymerizable monomer, a metathesis catalyst system comprising a transition metal catalyst and a cocatalyst, and a free radical initiator, and (b) subjecting the reaction mixture to temperature conditions to sequentially initiate polymerization of the norbornene monomer and the vinyl monomer.

Abstract: The present invention relates to a process and apparatus for the gas-phase polymerization of olefins in a fluidized-bed reactor maintained at a temperature T1. A gaseous reaction mixture comprising the olefins to be polymerized passes through the reactor and is recycled to the reactor by means of a recycling line comprising successively a first heat transfer means, a compressor and a second heat transfer means. The present invention consists in introducing a readily volatile liquid hydrocarbon into the inlet of the first heat transfer means or into the recycling line, upstream and in the vicinity of the first heat transfer means. The first heat transfer means cools the gaseous reaction mixture to a temperature T2, below T1, while volatilizing the readily volatile hydrocarbon and without condensing a constituent of the gaseous reaction mixture. The second heat transfer means cools the gaseous reaction mixture to a temperature T3, below T2, for maintaining the fluidized-bed at the desired temperature T1.

Abstract: Poly(4-hydroxystyrene) is prepared by aqueous suspension polymerization of 4-acetoxystyrene monomer followed by hydrolysis with ammonium hydroxide.

Abstract: High molecular weight, gel-free ethylene/vinyl acetate copolymers may be prepared by the process of solution polymerization if a particular relationship of temperature/pressure is observed.

Abstract: A process for producing polyethylene of ultrahigh molecular weight having an intrinsic viscosity of 10-30 dl/g at 135.degree. C. in decalin is disclosed which comprises at least the following two stages of polymerization reaction: (a) a first reaction stage where in ethylene is polymerized with use of a catalyst comprising a solid component containing at least Mg, Ti and/or Va and in the absence or presence of hydrogen of reduced concentration to produce 70-99.5 weight parts of polyethylene having an intrinsic viscosity of 12-32 dl/g at 135.degree. C. in decalin; and (b) a second reaction stage wherein a fresh feed of ethylene is polymerized in the presence of hydrogen of higher concentration to produce 30-0.5 weight parts of polyethylene having an intrinsic viscosity of 0.1-5 dl/g at 135.degree. C. in decalin.

Abstract: The specification discloses a monovinylidene aromatic polymer having a molecular weight of at least 50,000 and an extremely narrow molecular weight distribution of less than 1.5, preferably with at least 80% by weight of the polymer having a molecular weight within plus or minus 30% of the weight average molecular weight. This polymer is produced through anionic polymerization of a pure feed stock which is first cooled to a temperature at which an anionic initiator preferentially reacts with impurities present in the feed stock and initiates the polymerization reaction but does not substantially propagate styrene polymerization. The initiator is uniformly dispersed into the feed stock while maintaining it at the lower temperature and the feed stock temperature is subsequently increased to a temperature at which polymerization of the sytrene proceeds normally.

Abstract: Crosslinked, finely divided, water-absorbing polymers are prepared in a batchwise process by copolymerization of 100 parts by weight of a monomer mixture of acrylic acid or methacrylic acid, each of which is neutralized with from 0 to 100 mol% of an alkali metal or ammonium base,or acrylamide, methacrylamide or N-vinylpyrrolidone with, as a crosslinking agent, from 0.01 to 5 parts by weight of a monomer containing two or more ethylenically unsaturated double bonds in 20-80% by weight aqueous solution in the presence of an initiator in a multistage procedure in a batchwise mixing apparatus wih constant thorough mixing in all stages, in the first stage the aqueous monomer solution being copolymerized at from 45.degree. to 95.degree. C. and under from 0.1 to 0.8 bar with removal of some of the water by distillation, in the second stage the copolymerization being completed at from 100.degree. to 170.degree. C.

Abstract: Acetylene can be polymerized into a polyacetylene by a solid-state polymerization reaction when it is compressed into a solid under a high pressure of, for example, 1 GPa or higher. The polyacetylene product is obtained in a bulky transparent form in contrast to conventional polyacetylenes in a fibrous form prepared by utilizing a Ziegler-Natta catalyst, and free from impurities because neither catalyst nor solvent is used in the reaction.

Abstract: It has been determined that certain rubbery polymers having multiple glass transition temperatures can be utilized in making tires which have improved rolling resistance, improved wet skid resistance, and outstanding tread wear. These rubbery polymers are derived from at least one conjugated diolefin monomer, have a first glass transition temperature which is between -110.degree. C. and -20.degree. C. and have a second glass transition temperature which is between -50.degree. C. and 0.degree. C. These rubber polymers can be homopolymers of conjugated diolefin monomers, copolymers of more than one conjugated diolefin monomer, or copolymers derived from at least one conjugated diolefin monomer and at least one vinyl aromatic monomer.

Abstract: The time taken for a run of suspension polymerization of vinyl chloride monomer can be remarkably decreased without affecting the quality of the resin product when the temperature of the polymerization mixture under polymerization is increased continuously or step-wise during the period in which the conversion of the monomer to polymer is 10% or larger in such a manner that the average degree of polymerization of the polymer taken at an intermediate stage by sampling is always in the range from 90% to 110% of that of the finally obtained polyvinyl chloride resin product.

Abstract: A method for producing homopolymers and copolymers from amido-sulfonic acid or salt containing monomers in the presence of high energy mechanical mixing utilizing a final stage polymerization temperature of from about 200.degree. F. to below the degradation temperature of the monomer. The process produces a solid homopolymer or copolymer which can be utilized as fluid loss agents.

Abstract: A toner suitable for developing electrostatic images is produced through a process comprising: dispersing a monomer composition comprising at least a polymerizable monomer and a colorant in an aqueous medium heated at a temperature higher than a polymerization temperature, thereby to form particles of the monomer composition; adjusting the aqueous medium to the polymerization temperature; and adding a substantially water-insoluble polymerization initiator to the aqueous medium containing the particles of the monomer composition dispersed therein and adjusted to the polymerization temperature, thereby to cause the polymerization of the polymerizable monomer. According to this process, a toner containing a large amount of a low-softening point compound and having good fixability at low pressure and/or low temperature can be produced while retaining good anti-blocking characteristic and fluidity.

Abstract: A process for the gas phase production of a sticky, but fluidizable, polymer comprising (i) introducing at least one gaseous monomer, which is a precursor for the polymer, into a bed of particles located in a fluidized bed reactor at a velocity sufficient to cause the particles to separate and act as a fluid; (ii) introducing into the bed a catalyst adapted to cause the monomer to polymerize; (iii) contacting the catalyst with the monomer at a temperature below the sticking temperature of the polymer and at a temperature and pressure sufficient to polymerize the monomer in the presence of the catalyst whereby the polymer is produced; and (iv) passing the polymer from the fluidized bed reactor into at least one fluid bed reactor wherein a fluidizing gas is passed through a bed of particles at a velocity sufficient to cause the particles to separate and act as a fluid; the polymer is passed through the fluid bed reactor in an essentially plug flow mode; and the polymer is maintained in an agitated state.

Abstract: This invention concerns the production of 1,4-cis polybutadiene or copolymers of butadiene with other related diolefins through the catalytic polymerization or copolymerization of butadiene monomer by a continuous or discontinuous process carried out in the absence or substantial absence of solvents or diluents, operating in two successive phases (the first at a T<30.degree. C. and the second at a T=or>30.degree. C.) by control of the molecular weights.

Abstract: A process for producing a polymer or copolymer of 4-methyl-1-pentene, which comprises polymerizing 4-methyl-1-pentene or copolymerizing 4-methyl-1-pentene with up to about 20 mole % of an olefin having 2 to 20 carbon atoms in the presence of a catalyst comprising(A) a solid highly active titanium catalyst component composed of magnesium, titanium, halogen and a diester of a dicarboxylic acid,(B) an organoaluminum compound, and(C) an organosilicon compound represented by the following formulaR.sup.1.sub.3 Si(OR.sup.2)wherein each of R.sup.1 and R.sup.2 represents a hydrocarbon group with 1 to 5 carbon atoms, and the three R.sup.

Abstract: An improved process for recovery of ethylene from a polymerization process is described. A normally solid membrane is employed to recover an ethylene enriched gas stream from the polymerization vent gases. The ethylene enriched gas stream is recycled to the polymerization process.

Abstract: Ethylene is copolymerized with one or more 1-olefins under conditions of high temperature and pressure in the presence of an inert gaseous ratio modifier. As a result, liquid condensation which contributes to equipment damage and unsafe operation is avoided, and copolymer product density is readily controllable.

Abstract: A method of copolymerization in suspension of ethylene with straight-chain alpha-olefins so as to obtain low-density copolymers in two copolymerization steps in an aliphatic hydrocarbon medium having a boiling point above 40.degree. C. In the first reaction step the medium is supplied with a high-activity Ziegler catalyst on a carrier and with ethylene and the alpha-olefin. The copolymerization reaction is carried out for between 20 seconds and 30 minutes and at a temperature between 45.degree. and 65.degree.. The resulting copolymer is used in the second reaction step as a nucleus for polymerizing ethylene and the alpha-olefin, the reaction medium being supplied with additional quantities of ethylene and alpha-olefins so as to maintain the concentration of alpha-olefin in the reaction medium at between 4 and 25% by weight per 100 parts by weight of reaction medium and so as to maintain the pressure of ethylene at between 5 and 25 bars, the reaction being performed at a temperature between 50.degree. and 80.

Abstract: Tetrafluoroethylene fine powder resins are made by adjusting temperature during polymerization wherein:(a) at the beginning of the polymerization the temperature is between 70.degree.-90.degree. C.,(b) when between 5-30% of the total amount of tetrafluoroethylene has been polymerized, the temperature is raised to between 100.degree.-125.degree. C.,(c) after 20-80% of the total tetrafluoroethylene has been polymerized and after step (b) has been carried out, the temperature is lowered by at least 30.degree. C. from the temperature used in step (b).

Abstract: A polypropylene (PP) having a superior post-processability and blow moldability is provided, which PP is obtained by polymerizing propylene at multiple stages using a catalyst comprising a TiCl.sub.3 composition, an organoaluminum compound and a molecular weight (M.W.) modifier, the resulting final polymer comprising a higher M.W. portion and a lower M.W. portion having a melt flow index of 0.03 to 2.0 g/10 min., and between this index and a melt flow index (10.2 kg/10 minutes, 230.degree. C.) as measured under 5 times the load applied in the measurement of the former melt flow index, there being a relationship log HMI.gtoreq.0.922 log MI+1.44, and the final polymer consisting of 40 to 60 weight % of a PP portion corresponding to the higher M.W. portion and 60 to 40 weight % of a PP portion corresponding to the lower M.W. portion.

Abstract: A process for producing polymers or copolymers of ethylene, in which ethylene, optionally together with one or more copolymerizable compounds, is polymerized at a pressure above 50,000 kPa and a temperature of between 100.degree. and 400.degree. C. in the presence of an initiator, using an autoclave reactor and a tubular reactor connected in series with said autoclave reactor. The monomeric mixture in the presence of the initiator is passed first into a stirred autoclave, in which it is partially polymerized. Thereafter the reaction mixture from said autoclave, is passed through a heat exchanger, cooled to a pre-determined value, and then subsequently passed to a non-cooled tubular reactor, in which the further polymerization is carried out under adiabatic conditions.

Abstract: The process is described for the continuous suspension polymerization of vinyl chloride in aqueous phase, in which the polymerization mixture is subjected, in 2 zones, to treatment employing different process parameters in respect of final conversion, dwell time, number of theoretical cascade stages and stirrer power applied. This procedure gives, at good space-time yields, very uniform products which have a narrow particle size distribution, a high bulk density, good flow and a low speck count. In spite of using standard kettle material, only a very low formation of deposit on the kettle walls is observed.

Abstract: A method for processing a polymer solution by changing the thermodynamic state of the solution to produce a dilute phase and a concentrated phase such that the thermodynamic state is sufficiently changed that the two phases are formed by spinodal decomposition.