Hoechst Aktiengesellschaft

Ernst Schubert

Tatjana Poggi

Tibor Krakkay

Bernd Huber

Heinz-Paul Poter

The invention relates to filaments and fibers of acrylonitrile polymers, which contain 10 to 30% by weight of carboxyl groups, their use and processes for their production. The filaments and fibers exhibit, in the dry state, tensile strengths of more than 10 cN/tex and knot strengths of more than 6 cN/tex and can be processed on customary machinery and are suitable for the production of shaped structures of high water retention. The polymeric raw materials required for the spinning are produced by hydrolysis of acrylonitrile polymers using aqueous dilute acids in a heterogeneous phase system.

Filaments and fibers of acryling polymers which contain carboxyl groups

A fiber or filament of a swellable polymer of high tensile strength is made by spinning a polymeric raw material which is produced by agitating a suspension of solid particles of an acrylonitrile polymer in dilute sulfuric acid having an acid concentration between 40 to 50 percent by weight until the polymer is hydrolyzed to an extent that it contains from 10 to 30 percent by weight of carboxyl groups such that sticking of individual particles of the polymer to one another is avoided.

Process for producing filaments and fibers of acrylic polymers which

The invention relates to homopolymers and copolymers of acrylonitrile with very low Fikentscher K values of 34-15 and a total content of sulfonate and sulfate end groups, which do not originate from correspondingly substituted comonomers, of 250 to 1,000 milliequivalents per kilogram of polymer, 180 to 900 milliequivalents per kilogram being in the form of sulfonate end groups, and to suitable semi-continuous or continuous precipitation polymerization processes for their preparation by means of a redox system in an aqueous medium. The resulting polymers can be extruded to shaped articles. In particular, after hydrolysis, they can be used as emulsifiers and deep bore auxiliaries.

Process for preparation of acrylonitrile polymers with low K value

A method of inhibiting scale formation or precipitation in an aqueous alkaline-earth salt solution with an aqueous solution of a hydrolyzed polyacrylonitrile salt made by heating homopolymers and copolymers of acrylonitrile with very low Fikentscher K values of 34-15 and a total content of sulfonate and sulfate end groups, which do not originate from correspondingly substituted comonomers, of 250 to 1,000 milliequivalents per kilogram of polymer, 180 to 900 milliequivalents per kilogram being in the form of sulfonate end groups, and to suitable semi-continuous or continuous precipitation polymerization process for their preparation by means of a redox system in an aqueous medium.

Growing community of inventors

Kelheim/Donau, Germany

Ernst Schubert