摘要:
The present invention concerns a procedure for precipitating cellulose carbamate from an aqueous alkali solution. The solution is brought into contact with an aqueous solution of sulphuric acid containing one or several cations selected from the group consisting of Na, Al, Mg, Zn and Ca cations, whereby in the precipitation of cellulose carbamate the advantage is gained that the dry matter content of the fibre can be made high enough.
摘要:
An alkali-soluble cellulose derivative is produced by treating cellulose with liquid ammonia having urea dissolved therein, removing the ammonia, resulting in cellulose having urea distributed therethrough, and heating the thus obtained cellulose-urea to cause reaction between the urea and cellulose and form alkali-soluble cellulose carbamate. This cellulose carbamate can be precipitated from alkaline solution in the form of cellulose carbamate film or fiber.
摘要:
The present invention concerns a procedure for producing cellulose carbamate from cellulose and urea. To avoid alkali treatment of the cellulose used as starting material with a view to decreasing the degree of polymerization of the cellulose, the cellulose in web form is exposed to a radiation dose of preferably 0.5 to 10 Mrad from a radiation source, whereafter the cellulose is reacted with urea at elevated temperature.
摘要:
The present invention concerns improving the properties of cellulose carbamate fibres. The wet strength properties in particular can be improved by treating the fibres with alkalis or organic bases, aiming to reduce the number of carbamate groups. The procedure may also be applied in the manufacturing of regenerated cellulose fibres.
摘要:
A non-woven fibre product in which the fibre material consists, totally or in part, of fibres which are able to form bonds with natural or artificial fibres of the same or different type, and in which said fibres capable of forming bonds are cellulose carbamate fibres.
摘要:
The carbamate content of cellulose carbamate products is reduced by treating such products with solutions of a base, which solution also contains one or several alkali metal salts, particularly carbonates, sulfates, phosphates, borates and acetates.
摘要:
The carbamate content of cellulose carbamate products is reduced by treating such products with solutions of a base, which solution also contains one or several alkali metal salts, particularly carbonates, sulfates, phosphates, borates and acetates.