GB541383A - Softening treatment of sisal and other hard fibres - Google Patents

Abstract

541,383. Production of cellulose. GOUROCK ROPEWORK CO., Ltd., ELKIN, H. A., and WHITE, W. A. S. May 24, 1940, No. 9226. [Class 2 (ii)] Lignified fibres such as sisal, manila, or jute, are subjected to chlorination, e.g. with acidified calcium hypochlorite, and then to treatment with a solution of an organic base containing the group =RC-N =CR- or -RHC-NH-CHR- where R is a hydrogen atom or an alkyl or amino group or other group possessing neutral or basic properties capable of replacing one atom of hydrogen but not a group such as carboxyl or phenyl possessing acidic properties. Treatment with the organic base dissolves and removes the chloro-compound of the lignin and the fibres become sufficiently softened to enable them to be spun, e.g. into yarns capable of being readily woven into canvas or the like. Preferably, the fibres are preliminarily treated with a boiling dilute aqueous alkaline solution, and after they have been treated with the organic base, they may be immersed in a solution of a sulphonated oil or similar lubricating agent. In an example, the fibres are boiled with a solution of soft soap, washed, and immersed in a solution of calcium hypochlorite buffered to a pH of 4.5. The fibres are washed and then immersed in an aqueous solution of pyridine. The pyridine is then removed with dilute acetic acid and the fibres are washed, lubricated, and dried. Instead of pyridine there may be used diethylamine, piperidine, picoline, or isoquinoline.