| 摘要 |
525,158. Artificial filaments, films &c. COOP CONDENSFABRIEK FRIESLAND. Feb. 15, 1939, No. 5018. Convention date, March 1, 1938. [Class 2 (ii)] Fibres, filaments, threads, films and the like - obtained from protein solutions are hardened by subjecting them to treatment with a medium - containing formaldehyde at a temperature above 70 C. An aqueous bath may be used and it may contain salts, acids, bases, and organic substances, e.g. sodium chloride, magnesium sulphate, glycol, glucose, other aldehydes, ketones, or alcohols. Urea, thiourea, or phenol which form synthetic resins with formaldehyde may be incorporated in the treatment bath. Preferably the solution is made weakly alkaline. The treatment may be effected in a closed vessel at a temperature at or above the boiling point of the medium containing the formaldehyde. The materials may be subjected to a prehardening with a medium containing formaldehyde before being subjected to the hot treatment. The process may be applied to filaments or films obtained from a solution of a protein mixed with viscose. The protein substance may be of animal or vegetable origin. It may be casein. Instead of carrying out the treatment in a liquid medium, hardening may be effected in an atmosphere containing formaldehyde at high temperature and the atmosphere may contain ammonia and steam. Paraldehyde, or hexamethylene tetramine may be used instead of formaldehyde. |
