Rhodia Operations

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Rhodia Polyamide Intermediates

Rhodianyl

Matthieu Helft

Jean-Francois Thierry

Eric Roche

Jean-François Thierry

Sébastien Lomel

Caroll Vergelati

Vincent Mollet

Roland Durand

Bertrand Bordes

Cédric Fillon

Polyamides, e.g., polyhexamethylene adipamide, are continuously produced via the following stages:

Continuous production of polyamides

The present invention relates to a novel process for the manufacture of nonwoven surfaces. It relates more particularly to a process for the manufacture of nonwoven surfaces by the process of direct melt spinning of continuous filaments arranged in the form of a sheet. This process employs a composition based on a thermoplastic polymer exhibiting an electrical conductivity sufficient to prevent the formation of electrostatic charges or to allow their removal during the spinning process.

Process for the manufacture of nonwoven surfaces

Spherical polyamide particles having a mean particle size of less than 1 mm, notably less than 100 &#x3bc;m, are produced by dispersing the polyamide monomers in an inert liquid and then polymerizing same.

Production of spherical polyamide particles

The invention relates to a continuous process for manufacturing polyamides. The polyamides are of the type obtained from diacids and diamines. The process comprises an operation of continuous mixing of a compound which is rich in amine end groups and a compound which is rich in acid end groups and a polycondensation operation using the mixture. The invention relates to the starting phase of such a process, during which an aqueous solution comprising a mixture of monomers in substantially stoichiometric proportions is used.

Process for manufacturing polyamides

The invention concerns a method for making polyamide. More particularly, the invention concerns a method for making polyamides derived from the reaction between a diacid and a diamine. It concerns a method for making a polyamide derived from the reaction of at least a diacid with at least a polyamide comprising the following steps: preparing a first mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 0.8 and 0.995, preferably ranging between 0.95 and 0.99 in a first reactor ( ); preparing a second mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 1.005 and 1.2, preferably between 1.01 and 1.05, in a second reactor ( ); introducing in melted form a first flow of the first mixture and a second flow of the second mixture in a stirred polymer reactor ( ); drawing, preferably, continuously, from said reactor a flow of polyamide prepolymer; feeding said polyamide flow into a finishing step to obtain the desired degree of polymerisation. The invention is characterised in that the stoichiometry of the polyamide in the reactor ( ) or the acid function/amine function ratios in the different reactors are measured by near infrared spectrometric analysis, and by controlling the feed flows in the different reactors using the results of said analyses.

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Oullins, France

Matthieu Helft