| 摘要 |
In a method for the production of stuck sleeve or socket joints in polyethylene pipes an unsaturated polyester resin is used as the adhesive for the joint. By "unsaturated polyester resins" are meant mixtures of unsaturated polyesters with vinyl compounds, preferably aromatic vinyl compounds such as styrene, methylstyrene and chlorostyrene. The unsaturated polyesters are built up from glycols, polyglycols and if desired, polycyclic perhydric alcohols and dicarboxylic acids, for example mixtures of unsaturated acids such as maleic, fumaric, itaconic acids and Diels-Alder adducts of maleic anhydride with cyclopentadiene and saturated acids such as phthalic, tetrachlorophthalic, adipic and sebacic acids. For hardening there is added a catalyst such as cyclohexanone peroxide or methyl ethyl ketone peroxide and a polymerization accelerator such as cobalt naphthenate. Examples describe the joining of polythene tubes either socketed or with a slip on sleeve of polyvinyl chloride, the joints being stuck with a mixture of an unsaturated polyester prepared according to Specification 766,666, styrene, cyclohexanone peroxide and cobalt naphthenate. |
