PRODUCTION OF NATURAL LEATHER FINE POWDER AND NATURAL LEATHER FINE POWDER, SYNTHETIC LEATHER COMPOSITION, COATING MATERIAL AND SYNTHETIC LEATHER FORMED PRODUCT

摘要

PURPOSE:To obtain the title fine powder for use in novel materials, having natural-like feed, moisture absorptivity and releasability, non-electrostaticity and so on, by freezing natural leather chips impregnated with a liquid to loosen the collagen entanglement due to the resultant volume expansion followed by freeze-grinding. CONSTITUTION:Natural leather is cut into pieces normally =300mm (pref. =5mm) in size followed by impregnating said pieces with a liquid such as water. The resultant pieces are immersed in e.g., liquid nitrogen to perform quick freezing treatment, and the spiral fibrous collagen entangled mutually each other is allowed to be quickly and favorably disentangled as a result of the ice volume expansion induced by the above freezing. Thence, sufficient freeze-grinding treatment is carried out to obtain the objective natural leather fine powder with a size of virtually =40mum.