| 摘要 |
Filaments, threads, fibres, bands, films, and the like are obtained by extruding a solution of a protein in an alkali into a coagulating bath and hardening the products by means of formaldehyde or other hardening agent capable of reacting with the amino groups of the protein, and also hardening the products by means of one or more formates of polyvalent metals in solution with or without one or more formates of univalent metals or other salts or organic compounds. Hardening may be effected in a single bath containing formaldehyde, sodium formate and aluminium triformate. The polyvalent metal salt may be present as a complex salt. If desired, a coagulating bath containing a formate may be used and the filaments or other products may be passed, without washing, from this bath to a hardening bath containing a polyvalent metal salt, the coagulating liquid adhering to the products being used as a constituent of the hardening bath. A coagulating bath containing a salt of a polyvalent metal may be used and the unwashed products may be passed into a hardening bath containing a formate. In forming the protein solutions some of the alkali is absorbed by or combines with the protein molecules and the amount of free alkali in the solution is reduced. The amount of alkali used may be such that there is not more than 0.4 mols of free alkali per kg. of protein in the solution or it may be so small that there is no free alkali in the solution. Specification 577,526 is referred to. |
