Teijin Aramid B.v.

Anton Johannes Josef Hendriks

Mirjam Ellen Oldenzeel

Tetsuya Akamatsu

René Journee

Harrie Grotendorst

Johannus Maria Bergmans

Dennis Wilbers

Jan Davis Cornelis Tiecken

Vincent A Van Bommel

A para-aramid fibrid film is disclosed that has at least 95% of the bonds of the polymer are para-oriented. A method for making said para-aramid fibrid film by (a) polymerizing a para-oriented aromatic diamine and a para-oriented aromatic dicarboxylic acid halide to an aramid polymer having only para-oriented bonds in a mixture of solvents consisting of N-methylpyrrolidone or dimethylacetamide and calcium chloride or lithium chloride to obtain a dope wherein the polymer is dissolved in the mixture of solvents and the polymer concentration is 2 to 6 wt. %, and (b) converting the dope to para-aramid fibrid film is also described.

Para-aramid fibrid film

The invention pertains to a method for making a polymer-additive composite particle from a dope by jet spinning the dope to obtain a pulp, fibril or fibrid, wherein the solvent of the dope is selected from N-methyl-2-pyrrolidone, N,N'-dimethylformamide, N,N&#x2032;-dimethylacetamide, tetramethylurea, and 4 to 75 wt % of a composition consisting of 2 to 95 wt % of a para-aramid polymer and 5-98 wt % of a solid additive material, to a total of 100 wt %, and wherein the aramid polymer is dissolved in the solvent; or coagulating the dope by means of a rotor-stator apparatus in which the polymer solution is applied through the stator on the rotor so that the precipitating polymer-additive composite particle is subjected to shear forces while they are in a plastic deformable stage.

Particles comprising composite of para-aramid and additive material

Aramid fibrils having in the wet phase a Canadian Standard Freeness (CSF) value less than 100 ml, after drying a specific surface area (SSA) less than 7 m/g, and a weight weighted length for particles having a length &#x3e;250 &#x3bc;m (WL 0.25) less than 1.2 mm, are described. A method of preparing the fibrils includes the steps (a) polymerizing an aromatic diamine and an aromatic dicarboxylic acid halide to an aramid polymer, in a mixture of N-methylpyrrolidone or dimethylacetamide and calcium chloride or lithium chloride to obtain a dope wherein the polymer is dissolved in the mixture and the polymer concentration is 2 to 6 wt. %, (b) converting the dope to fibrils by using a jet spin nozzle under a gas stream, and (c) coagulating the fibrils using a coagulation jet.

Aramid fibrils

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Lent, Netherlands

Anton Johannes Josef Hendriks