| 摘要 |
A moulding-composition which when moulded will produce articles having a pearlescent character is prepared by forming a homogeneous mixture of metallic particles and a thermoplastic reaction product of rubber and a halogen acid of tin. The composition may also contain dyestuffs with or without pigments. The preferred metallic particles are aluminium, copper, bronze magnesium, lead and zinc added in amounts of 0,1 to 1,0 parts per 100 parts of plastic material. The composition also preferably contains a soap such as castile soap to assist in the even distribution of the metal particles on moulding. The colouring effects are varied to some extent by the particle size of the metallic powder, the particle size of the moulding powder as it is placed in the mould, and the temperature at which the moulding operation is carried out. A thermoplastic rubber derivative suitable for use in the present invention is prepared by plasticizing raw rubber with benzene to form a cement, and reacting the cement in a steam jacketed mixer with 10 per cent of hydrated chlorostannic acid for approx. 3 hours. The exact time of reaction is determined by the viscosity desired in the final product; a longer reaction time yielding a harder product. The reaction product is discharged into its own volume of water preferably containing a little sodium sulphite, and the benzene removed by steam distillation to yield a sand like product which contains chlorine and appears to be a hydrogen chloride addition product. This material is thermoplastic and metallic particles may be uniformly distributed in it by milling. This product is then ground to form the moulding powder of the invention. The Specification as open to inspection under Sect. 91 comprises also the incorporation of metallic powder into any thermoplastic material. Materials mentioned are the reaction product of rubber with hydrochloric acid and the halide of an amphoteric metal, polymerized vinyl compounds, styrol plastic compounds, and cellulose plastics such as cellulose acetate and cellulose nitrate. This subject-matter does not appear in the Specification as accepted, but forms the subject-matter of Specification 440,879. |
