| 摘要 |
A process for producing plastic compositions from a vinyl halide polymer or copolymer, in which hydrocarbons of molecular weight 200-800, and having initial and final boiling points within 250-800 DEG C. at 760 mm. Hg pressure, and a high carbon content (at least 0.6 atoms of carbon per atom of hydrogen) and containing up to two unsaturated linkages per molecule, are extracted from mineral oil fractions or residues with a selective polar solvent or mixture of selective solvents, the extracted hydrocarbons being air-blown at 150-300 DEG C. for up to 50 hours or more, and the treated hydrocarbons then incorporated in the polymer or copolymer with or without a known plasticizer. Polyvinyl chloride and copolymers of vinyl chloride are mentioned. Dibutyl phthalate is the only specified known plasticizer. The mineral oil fractions are first extracted with a selective polar solvent or mixture, the extract distilled to recover the hydrocarbons which are air-blown. The selective polar solvents are sulphur dioxide, alcohols, furfural, phenols or a mixture of sulphur dioxide and benzene. The extract hydrocarbons may be further processed, e.g. by distillation, partial absorption on porous earths or precipitation by solvents, to render them lighter in colour. The resulting compositions have good low temperature resistance and electrical properties. In examples (1), (3) and (5), the preparation of the fractions by extraction with sulphur dioxide and benzene and air blowing is described. (6) The electrical properties of a composition comprising polyvinyl chloride, dibutyl phthalate and the air-blown extract hydrocarbons are compared with those of a similar composition, but containing extract hydrocarbons not air blown, and (2) and (4) as for (6), but the compositions including also lead silicate and ethyl palmitate. |
