Improvements in or relating to methods of obtaining industrially useful products from material, preferably scrap or waste material, comprising a fibrous base charged with a cellulose derivative or to products which may be obtained from such material

摘要

554,838. Cellulose derivatives and compositions. BRITISH UNITED SHOE MACHINERY CO., Ltd., and MACDONALD, D. B. Jan. 17, 1942, No. 718. [Class 2 (ii)] Fibrous sheet material, particularly scrap or waste material, comprising cellulosic or wool fibres and impregnated with a cellulose ester or ether in precipitated or porous condition is subjected to treatment with a dilute acid or other degrading agent so as to reduce or destroy the strength of the fibres, and the material is then crumbled, shredded or otherwise reduced to comminuted condition. The treatment is such that the cellulose derivative is substantially unaffected. The comminuted material may be treated with a solvent for the cellulose derivative and a solution or plastic may be obtained in which the comminuted fibres serve as a binder or filler. The solutions or plastics may be used for making films, coatings, paints, cements, stiffened fabric or paper sheets, shoe stiffeners, or fillings for the bottom cavities of shoes. The material to be treated may be waste cuttings from cotton cloth charged with cellulose nitrate in precipitated or porous condition, such material being obtained when cutting out shoe toe puffs and other shaped parts. Cloth, felt, or paper materials charged with cellulose derivatives may be treated. Dilute sulphuric, hydrochloric, or nitric acid may be used as degrading agent. In the case of cellulose fibres, the cellulose is probably converted into hydrocellulose or oxycellulose. Sulphuric acid of 3-4 per cent. strength by volume or nitric acid of about 5 per cent. by volume may be used. The treatment may be carried out at raised temperature. The extent of the treatment and the grinding are varied according to the desired state of subdivision of the fibres which may be obtained as a fine powder or as short fibres of say one-eighth of an inch. After the acid treatment the material is preferably washed and dried. Specifications 117,068, [Class 15 (ii)], 143,310, [Class 140], 344,510, 390,290, 469,014, [Group VII], 507,138, and 524,415 are referred to.