Akzo Nobel N.v.

Akzo N.v.

Akzo Nobel Chemicals International B.v.

Hans Westmijze

Andreas Petrus Van Swieten

Koen Antoon Kornelis Vanduffel

Lambertus Meulenbrugge

Boen Ho O

John Meijer

Johannes Jacobus Theodorus De Jong

Jacobus Schut

Andreas Herman Hogt

Johannes Willibrordus Antonius Overkamp

Eltjo Boelema

Petrus Johannes Alferink

Koen Antoon Vanduffel

The invention pertains to a process wherein initiators having a half-life from 0.0001 hour to 0.05 hour at the polymerization temperature are dosed to a polymerization mixture. The dosing of such initiator allows improved control of the polymerization rate and faster polymerization rates, and the process will render a polymer with very low residual initiator levels.

Continuous dosing of extremely fast initiators during polymerization reactions

The invention pertains to a process to polymerize one or more monomers wherein at most 90% w/w of a safely useable amount of a first initiator is used and a second initiator is dosed at least after the start of the polymerization, in an amount such that essentially the full cooling capacity of the polymerization reactor is used, resulting in a cost efficient process to make polymers, particularly polymers comprising polymerized vinyl chloride.

Increased polymerization reactor output by using a specific initiator system

The invention pertains to a process to polymerize one or more monomers wherein one or more initiators and optionally one or more surfactants are added to a polymerization mixture when the pressure in the polymerization reactor is dropping. This process allows a shorter polymerization time due to a higher pressure drop rate at the end of the polymerization reaction. Moreover, the cooling capacity of the polymerization reactor is used more efficiently.

Addition of organic initiators during the pressure drop in vinyl chloride monomer polymerization reactions

The present invention relates to an aqueous dispersion polymerization process for preparing a (co)polymer wherein an organic peroxide is used as initiator (as a source of free radicals) during the polymerization process in conjunction with an effective amount of an organic peroxide stabilizing additive (controlling agent). The invention also relates to formulations comprising an organic peroxide and an effective amount of an organic peroxide stabilizing additive suitable for use in said polymerization process. The invention finally relates to 10 (co)polymers obtainable by the dispersion polymerization process.

Polymerization process for preparing (co)polymers

The invention relates to highly concentrated aqueous emulsions of peroxides comprising an anti-freeze agent, a polyvinyl acetate with a degree of hydrolysis between 45 and 80%, and optionally a non-ionic surfactant with an HLB value greater than 10 selected from alkylene oxide block-copolymers, ethoxylated fatty alcohols, and ethoxyfated fatty acids. The emulsions have a low COD value and are safe, storage stable, and generally applicable.

Highly concentrated, stable, and safe diacyl peroxide and peroxydicarbonate emulsions with a low chemical oxygen demand value

The invention relates to a polymerization process wherein at least one peroxide, with a half life in between 1 hour and 0.001 hour at the polymerization temperature at the moment of dosing, is dosed to the reaction mixture at the polymerization temperature and wherein at least during part of the period in which the peroxide is dosed i) the cooling means of the reactor are kept at essentially maximum cooling capacity and ii) the amount of initiator that is dosed is actively controlled such that the desired polymerization temperature is achieved and maintained within 0.3&#xb0; C. of said polymerization temperature.

Polymerization process involving the dosing initiators

The invention pertains to a process wherein initiators and protective colloids are both metered to a polymerization mixture. This manner of metering allows for improved control of the polymerization rate and an improved reactor space-time yield, and the process will render a polymer with a relatively high porosity.

Co-metering of organic initiators and protective colloids during polymerization reactions

The invention pertains to a process wherein peroxides are dosed to a polymerization mixture, with essentially all of the organic peroxide that is used in the polymerization process having a half-life from 0.05 hour to 1.0 hour at the polymerization temperature. The dosing of such peroxide allows for accurate control of the polymerization rate, and the process will render a polymer with a low residual peroxide level.

Continuous dosing of very fast initiators during polymerization reactions

The invention relates to aqueous emulsions of peroxyesters comprising an anti-freeze agent, a polyvinyl acetate with a degree of hydrolysis between 45 and 68%, and a non-ionic surfactant with an HLB value greater than 16 selected from alkylene oxide block-copolymers, ethoxylated fatty alcohols, and ethoxylated fatty acids. The emulsions are safe, storage stable, and generally applicable.

Emulsions of peroxyesters

The invention pertains to a process for enhancing the melt strength of a polypropylene (co)polymer with the aid of initiator dispersions. The use of initiator dispersions with a particulate initiator instead of the corresponding non-dispersed initiators or their dilutions or solutions results in a significant enhancement of the melt strength of the modified polymer, and a wide range of initiators turn out to be serviceable.

Process for enhancing the melt strength of polypropylene (co)polymers

Use of peroxyacids as molecular weight regulators

This disclosure relates to novel peroxy esters carrying a t-alkenyl, e.g. 2-methyl-3-butene-2-yl, peroxy group. These peroxy esters have shorter half-life periods of decomposition and are more reactive polymerization initiators and unsaturated polyester resin curing agents than the corresponding prior art peroxy esters carrying a t-alkyl, e.g. t-amyl, peroxy group.

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Bathmen, Netherlands

Hans Westmijze