| 摘要 |
A thermoplastic copolyester composition that is able to maintain its color and mechanical strength after exposure to full weathering is provided. More specifically, a stabilizing system is employed in the composition that contains a mixture of one or more light stabilizers (e.g., hindered amines, UV absorbers, etc.), antioxidants (e.g., sterically hindered phenols, organophosphorous compounds, etc.), and secondary amines. By selectively controlling the type and concentration of the stabilizers, the present inventor has discovered that a composition may be formed that is generally resistant to color change and crazing (i.e., micro-crack formation) upon weathering. In addition to a stabilizing system, a processing stabilizer is also employed in the copolyester resin that includes a metal salt of a fatty acid having a chain length of greater than 22 carbon atoms. The present inventor has discovered that such stabilizers are particularly effective in reducing internal stresses during fiber or film formation and thereby minimizing brittleness of the resulting article. For example, a monofilament formed from the thermoplastic copolyester resin of the present invention may exhibit an elongation at break retention percentage of from about 85% to about 150% after exposure to a Xenon arc at 2000 kJ/m2 in accordance with Test Method SAE J1960. |
