| abstract |
A fiber of a sea-island phase separation structure in which the sea phase is made of a highly orientable and highly crystalline polyvinyl alcohol polymer, the island phase is made of a water-insoluble cellulosic polymer excellent in alkaline liquid absorbing capacity, heat resistance and difficulty of melting, the size of the island is 0.03 to 10 νm and the strength is 3 g/d or above and which can easily be separated into fibrils 0.05 to 8 νm in diameter by wetting the fiber and applying a mechanical stress to the resulting fiber. The above fibril is a hydrophilic and high-strength one which is excellent in the property of capturing fine particles, reinforcing effects, alkaline liquid absorption, and the resistances to heating and melting, does not cause the elution of fiber components in fibrillation, and is freed from the problematic bubbling in beating or the problem of environmental pollution due to a heating solution. The fibril is extremely useful as the separator paper for alkaline batteries, the reinforcing fiber for cement slates, the reinforcing fiber for friction materials, or the like. |