Polyoxymethylene fibrids, a process for their production and their use
AssigneeHoechst Aktiengesellschaft
InventorsHarald Cherdron, Wolfgang Gordon, Friedrich Kloos
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Abstract
The invention relates to polyoxymethylene fibrids with a reduced specific viscosity of 0.4 to 2.0 dl/g, a specific surface area of 50 to 200 m.sup.2 /g and a freeness of 30.degree. to 80.degree. SR. The fibrids are produced by flash-evaporation of a superheated solution of the polymer, a mixture of 50-95% by weight of a lower alcohol with 1-4 C atoms and 5-50% by weight of water being used as the solvent and are suitable for the production of paper.
Claims6
Highly branched polyoxymethylene fibrids with a reduced specific viscosity of 0.4 to 2.0 dl/g, a specific surface area of 50 to 200 m.sup.2 /g, said specific surface area being measured at 140.degree. C. in butyrolactone, which contains 2% by weight of diphenylamine, in a concentration of 0.5 g/100 ml, a freeness of 30.degree. to 80.degree. SR, a length of about 0.1 mm to 5 mm and an apparent diameter of about 1 to 200 .mu.m.
Polyoxymethylene fibrids, as clamied in 1, in which the specific surface area is 70 to 110 m.sup.2 /g.
Dependencies are inferred from the claim text.