| 摘要 |
PURPOSE:To provide the title lubricant having a low torque and excellent surface roughness and lubricity and useful for manufacturing a pipe having high hardness, which comprises a first liq. contg. a graphite powder and a water-soluble resin and a second liq. contg. a particular crosslinking agent. CONSTITUTION:85% or less in total of 5wt.% (hereinafter referred to as '%'), pref. 15-50% graphite powder (A) comprising a fine powder of natural or artificial graphite and at least 5%, pref. 15-50% reactive curable base material composed of a water-soluble resin (e.g., PVA modified so as to have an aldehyde group) is mixed with water (C) and, if necessary, additives (D) such as a thickener, a preservative, a rust preventive, an extreme pressure agent, and an antifoaming agent, thereby preparing a first liq. Separately, at least 5% crosslinking agent (E) composed of at least one member selected from among boric acid (amine salt) and metal salts of boric acid is optionally mixed with additives (F) such as component C and a rust preventive. The first liq. is applied in a coating thickness of 10-200mum. The second liq. is uniformly applied thereon through spraying, followed by drying. |
