Akzo Nobel N.v.

Akzo Nobel Chemicals International B.v.

Koen Antoon Kornelis Vanduffel

Lambertus Meulenbrugge

Hans Westmijze

Andreas Petrus Van Swieten

Johannes Jacobus Theodorus De Jong

Carolina Anna Maria Christina Dirix

Johannes Willibrordus Antonius Overkamp

Johan Nuysink

Petrus Paulus Waanders

Polymerization process comprising the steps of: (a) reacting an aqueous suspension comprising initiator, vinyl chloride, and optionally one or more co-monomers in a continuous stirred tank reactor; and (b) further reacting the resulting suspension in at least one second reactor; wherein the conversion level of vinyl chloride in the continuous stirred tank reactor of step (a) is from 10 to 60 wt %.

Continuous process for the production of vinyl chloride (co)polymers

Emulsion comprising an oil phase dispersed in an aqueous phase, wherein said oil phase comprises at least 53 wt % of one or more organic peroxides, more than 50 wt % of which have a molecular active oxygen content of at least 7.00 5 wt %, said emulsion satisfying the classification tests for organic peroxide type F. This emulsion allows the safe transport and storage of organic peroxide emulsions with high active oxygen content without the need for larger vent openings or higher design pressure of transport tanks and storage tanks.

Storage stable and safe peroxide emulsions with a high active oxygen content

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 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.

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Deventer, Netherlands

Koen Antoon Kornelis Vanduffel