Dsm IP Assets B.v.

Bas Van Laarhoven

Christiaan Johannes Cornelis Stoelwinder

Mark Helmsing

Eric Grolman

Michiel Muyris

Gerard Jan Kwant

Processes for preparing a polyamide, a polyamide material obtained by such processes, a nylon salt to be used therein, and processes for making the nylon salt are disclosed. The processes for preparing the polyamide include a direct solid state polymerization process. The salt used herein is a granulate material, prepared by a process, comprising spraying an aqueous solution comprising a diamine and a dicarboxylic acid dissolved in an aqueous medium, or an aqueous slurry comprising a diammonium dicarboxylate salt dispersed in an aqueous medium directly obtained from such an aqueous solution, onto or in a fluidized bed of diammonium dicarboxylate salt particles, while evaporating the aqueous medium, thereby forming a granulate salt material.

Process for preparing a polyamide, a nylon salt to be used therein and a process for making the salt

The present invention relates to a process for preparing a granular nylon salt material, wherein an aqueous mixture, comprising at least 65 wt. % of salt components, and at most 35 wt. % of an aqueous medium, the weight percentages (wt. %) being relative to the total weight of the aqueous mixture, is flashed from a pressure vessel via a flash valve into a flash chamber, thereby evaporating the aqueous medium in an amount sufficient to result in a residual moisture content of at most 7.5 wt. %, and forming a granular nylon salt material. The invention also relates to a process for preparing a nylon polymer, comprising direct solid state polymerization of the granular salt material prepared by flash granulation.

Process for preparing nylon salt and its polymerization

The present invention relates to a process for preparing a polyamide, a polyamide material obtainable by the said process, a nylon salt to be used therein, and a process for making the nylon salt. The process for preparing the polyamide is a direct solid state polymerization process. The salt used herein is a granulate material, prepared by a process, comprising spraying an aqueous solution comprising a diamine and a dicarboxylic acid dissolved in an aqueous medium, or an aqueous slurry comprising a diammonium dicarboxylate salt dispersed in an aqueous medium directly obtained from such an aqueous solution, onto or in a fluidized bed of diammonium dicarboxylate salt particles, while evaporating the aqueous medium, thereby forming a granulate salt material.

The invention relates to a method for producing a free flowing flame retardant material, comprising steps of i. preparing an aqueous slurry from a freshly prepared moist melam having a water content of at least 8 wt. %, relative to the total weight of the moist melam, the slurry comprising water, melam and a water soluble polymeric binding agent, wherein the melam is present in an amount of 5-35 wt. % relative to the total weight of the slurry, and the water soluble polymeric binding agent is present in an amount of 0.5-8 wt. % relative to the total amount of melam and the water soluble polymeric binding agent; ii. drying the slurry in a fluid bed to form a granulate material; and iii. collecting the resulting granulate material. The invention also relates to a melam granulate material, obtainable by said process.

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Echt, Netherlands

Bas Van Laarhoven