Patent ID: 7186806

Claim:
A process for producing regenerated collagen fiber which comprises treating regenerated collagen fiber with a monofunctional epoxy compound and a metal aluminum salt, wherein treatment with said monofunctional epoxy compound is initiated by adding sodium hydroxide to become 0.001 to 0.8 N based on treatment solution and inorganic salt selected from the group consisting of sodium sulfate, sodium chloride, and ammonium sulfate in an amount which is at least 13% by weight and up to an amount so that solution reaches the saturated concentration at 25° C. when the sodium hydroxide concentration of the reaction solution is at least 0.001 N and less than 0.05 N, at least 15% by weight and up to an amount so that solution reaches the saturated concentration at 25° C. when the sodium hydroxide concentration is at least 0.05 N and less than 0.15 N, at least 16% by weight and up to an amount so that solution reaches the saturated concentration at 25° C. when the sodium hydroxide concentration is at least 0.15 N and less than 0.35 N, at least 19% by weight and up to an amount so that solution reaches the saturated concentration at 25° C. when the sodium hydroxide concentration is at least 0.35 N and at most 0.8 N.