Patent GB-616421-A (GB)
Title: Process for the production of stable, non-gelatinising solutions of cellulose
IPC: C08B1/00
Filed: 1946-09-06
Abstract: Stable, non-gelatinising solutions of cellulose are obtained by the swelling of natural or regenerated cellulose in caustic soda solution of at least 20 per cent strength and containing zinc oxide, together with a substance having the general formula Halogen-CH2-R, where R represents a carboxyl, alkyl-carboxyl, aldehyde, alkyl-carbonyl, oxyalkyl or alkoxyl group or an alkylene oxide residue, the solution of the cellulose taking place on dilution.  Suitable substances which may be added are chloracetic acid and its esters, chloracetaldehyde, monochloracetone, ethylene chlorhydrin, chloromethyl ethyl ether and epichlorhydrin.  Both natural and regenerated cellulose may be used as starting materials.  The sodium zincate solution may be prepared by dissolving 1 part by weight of zinc oxide in a concentrated solution containing three parts caustic soda, warming and diluting so that the NaOH content is not less than 20 per cent and the ZnO content 5-15 per cent.  Using natural cellulose materials a higher initial concentration is needed.  The concentration of NaOH in the solution after final dilution to dissolve the cellulose should not be more than 10 per cent.  The solutions may be used for stiffening textiles, e.g. by first impregnating with the cellulose solution and then with a precipitation bath containing sulphuric acid and sodium sulphate, or by mercerizing after impregnation.  Matt prints on fabrics may be obtained by mixing pigments with the solution, printing and treating in an acid precipitation bath.  In an example, 5 kg. of short length viscose waste are mixed with 35 kg. of sodium zincate containing 21.5 per cent NaOH and 7.0 per cent ZnO, and 1 kg. ethylene chlorhydrin added with kneading.  After standing 2-3 hours, it is diluted with 59 kg. water, a clear homogeneous solution being obtained.ALSO:Stable, non-gelatinising solutions of cellulose are obtained by the swelling of natural or regenerated cellulose in caustic soda solution of at least 20 per cent strength and containing zinc oxide, together with a substance having the general formula Halogen-CH2-R, where R represents a carboxyl, alkyl-carboxyl, aldehyde, alkyl-carbonyl, oxyalkyl or alkoxyl group or an alkylene oxide residue, the solution of the cellulose taking place on dilution.  These solutions may be used for stiffening textiles by first impregnating the textile, and then treating with a precipitating bath containing sulphuric acid and sodium sulphate or by mercerizing after impregnation.  Suitable substances which may be added to the sodium zincate solution are chloracetic acid and its esters, chloracetaldehyde, monochloracetone, ethylene chlorhydrin, chloromethyl ethyl ether and epichlorhydrin.  Both natural and regenerated cellulose may be used as starting materials.  The sodium zincate solution may be prepared by dissolving 1 part by weight of zinc oxide in a concentrated solution containing three parts caustic soda, warming and diluting so that the NaOH content is not less than 20 per cent and the ZnO content 5-15 per cent.  Using natural cellulose materials a higher initial concentration is needed.  The concentration of NaOH in the solution after final dilution to dissolve the cellulose should not be more than 10 per cent.  Matt prints on fabrics may be obtained by mixing pigments with the solution, printing and treating in an acid precipitation bath.  In an example, a treating solution is prepared by mixing 5 kg. of short length viscose waste with 35 kg. of sodium zincate containing 21.5 per cent NaOH and 7.0 per cent ZnO, and 1 kg. ethylene chlorhydrin added with kneading.  After standing 2-3 hours it is diluted with 59 kg. water, a clear homogenous solution being obtained.