Abstract: The present invention has its object to provide a lubricant for fibers which shows, in particular, good anti-tackiness property against fiber-to-fiber tackiness in the manufacture of elastic fibers, and good time-dependent stability for a long period of time as a lubricant for treating fibers. The present invention provides a lubricant for treating fibers to be used for fibers made of a polymer material (a) wherein the angle of contact with water at 25° C. of the surface of a sheet made of the material (a) is not greater than 60° and the angle of contact with water at 25° C. of the surface of the sheet made of the material (a) applied with the lubricant for treating fibers is 70° to 180°.

Abstract: The present invention provides a lubricant for treating elastic fiber which comprises at least 80 mass % of at least one base oil (A) having a viscosity at 25° C. of 1 to 1,000 mm2/s as selected from the group consisting of silicone oil (A1) and hydrocarbon series lubricating oil (A2), 0.05 to 2 mass % of a C12 to 24 higher fatty acid alkaline earth metal salt (B) having a volume average particle diameter of 0.001 to 1 ?m, and 0.01 to 8 mass % of at least one surfactant (C) having a solubility parameter (SP value) of 8.0 to 10.5 as selected from the group consisting of anionic surfactant (C1) and nonionic surfactant (C2).

Abstract: The present invention provides a spin finish for elastic fibers which comprises an amphoteric surfactant and/or a cationic surfactant as well as a base oil and has a surface tension thereof at 25 of 14 to 35 mN/m and a volume resistivity thereof at 20 of 1×107 to 1×1013 &OHgr; cm; a spin finish for elastic fibers which comprises an ionic surfactant and a base oil and has a surface tension (S) thereof at 25° C. of 14 to 22.5 mN/m and a volume resistivity (&rgr;) thereof at 20° C. of 1×107 to 1×1013 &OHgr; cm, &rgr; and S satisfying the following relation [1]; &rgr;≦1×10(−2.4S+61)  [1] a spin finish for elastic fibers which comprises a quaternary ammonium salt of the specific composition, a base oil and a higher fatty acid (C5-30) metal salt powder; a method of treating an elastic fiber which comprises providing an elastic fiber with any of the above spin finish for elastic fibers in an amount of 0.

Abstract: The present invention provides a spin finish for elastic fibers which comprises an amphoteric surfactant and/or a cationic surfactant as well as a base oil and has a surface tension thereof at 25° C. of 14 to 35 mN/m and a volume resistivity thereof at 20° C.