GB1041840A - Improvements in or relating to products comprising organic derivatives of cellulose - Google Patents

Abstract

A process for the production of rolled sheet or extruded material or moulding powder formed therefrom comprises agitating with a plasticizer solid particles of a substantially water-insoluble cellulose derivative component, which component has not been dried and contains more than 20% by weight of water, and rolling the mixture of cellulose derivative component and plasticizer into the form of a sheet or extruding the said mixture into the required form or shape or forming moulding powder therefrom. The cellulose derivative component may contain more than 50% by weight of water, especially 1 to 2 1/2 parts by weight of water to 1 part by weight of the cellulose derivative, solid particles of which are approximately 1/4 inch in size. Cellulose acetate is specified as a suitable cellulose derivative. Specified plasticizers include diethyl phthalate, dimethyl phthalate, and a mixture of the two with or without a solid plasticizer, e.g. triphenyl phosphate. Solid particles of the cellulose derivative component may be agitated with a plasticizer in the presence of suitable colouring or pigment material and/or filler material. Suitably, the mixture of the cellulose derivative component and plasticizer is processed on hot compounding rolls to form sheet material which is either diced and cut or broken up to form moulding powder or further processed on hot calenders to obtain smooth sheet material of predetermined thickness. Alternatively, the mixture of the cellulose derivative component and plasticizer is extruded in an extrusion apparatus suitably vented to allow for removal of water, the extrudate being cut or broken up into moulding powder.