| 摘要 |
A composite elongated-shaped product is made from two or more synthetic polymer components. The product may be a split-fiber, thread, film or a ribbon-shaped one. One of the polymer components is polypropylene which forms more than 50 percent by weight of the product. At least one other polymer component is distributed in the polypropylene. The composite product contains 65 to 95 percent by weight of polypropylene and 35 to 5 percent by weight of one or more polyesters and/or polyamides. The polyesters are built up of structural units derived from one or more dicarboxylic acids, at least 70 mole % of which are from terephthalic acid. Other structural units are derived from one or more low-molecular weight diols, at least 70 mole % of which are from a diol having the formula HO(CH2)nOH, where n is a whole number and may be 2, 4 or 6. The polyamides are formed by polycondensation of caprolactam or adipic acid and hexamethylene-1,6-diamine. The polyester or polyamides are partly present in the form of fibrils. The tensile strength Y of the oriented composite product is at least equal to Y=1.1X, where X is the tensile strength of a corresponding elongated-shaped product which is a practically 100% polypropylene product having a melt index of 3 and was made in the same way as the composite elongated-shaped product, X being greater than or equal to 45 cN/tex in the case where the product is formed by split-fiber and X being greater than or equal to 35 cN/tex for ribbon or film-shaped products, i.e. in the case where the product is not formed of split-fibers, the value of X being greater than or equal to 50 cN/tex for thread-shaped products such as monofilaments. |
