Montefibre S.p.a.

Luigi Patron

Raffaele Tedesco

Paolo Melacini

Favato Veneto

Enzo Trevisan

Pier Luigi Mazzuco

Giorgio Doria

Ennio Niero

An improved process for the wet-spinning of acrylic polymers is disclosed, wherein a spinning solution of an acrylic polymer in an organic solvent, such as dimethylacetamide or dimethylformamide, is extruded through a spinneret into a coagulating bath consisting essentially of water and an organic solvent in a ratio between 30:70 and 60:40 by weight, and wherein the filaments thus obtained are washed, stretched and heat treated, and wherein the coagulating bath contains from 0.03% to 3% by weight of acid corresponding to said organic solvent and has a pH value greater than 5, and preferably between 6.5 and 8. The spinning solvent is preferably dimethylacetamide containing free acetic acid to an extent of less than 0.1% by weight, the acetic acid if necessary being added to the coagulating bath to bring its concentration up to values between 0.03% and 3% by weight. The pH value greater than 5 is obtained by the addition to the coagulating bath of ammonium hydroxide, an alkali metal hydroxide, or dimethylamine.

Process for spinning acrylic polymers

Continuous process for preparing a spinning solution of acrylic polymeric material. Process utilizes acrylic polymers obtained in a bulk polymerization slurry, and comprises adding a solvent such as dimethylacetamide to the slurry in such quantity as to be insufficient to attack and dissolve the polymer, bringing the resulting mixture to a temperature not exceeding 170.degree.C, such temperature being such as to not result in any appreciable attack of the polymer by the solvent, removing unreacted monomer by vacuum adiabatic evaporation, and then heating to a temperature not exceeding 170.degree.C, such temperature being sufficiently high to result in solvent attack and dissolution of the polymer.

Continuous process for preparing a spinning solution of acrylic polymers

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Venice, Italy

Luigi Patron