ナイロン網糸の紫外線劣化に対する添加剤の効果

抄録

The effect of five additives on the phtodegradation of two types of nylon netting twines (multifilament and monofilament) was investigated. The ultraviolet irradiation was carried out by using carbon arc light source (Fade meter). The progress of photodegradation of the samples after irradiation was evaluated by measuring the loss of mechanical properties and scanning electron micrograph (SEM) examination.
As the results of the comparison of two kinds of exposure tests on the multifilament nylon, it was estimated that about 200 hours irradiation in the Fade meter was equivaelnt to approximately 1 year of outdoor exposure to produce the same strength loss.
A remarkable loss in breaking strength and elongation were observed with irradiation time. Of the two nylon netting twines, multifilament nylon was found to undergo degradation at a faster rate than monofilament. The results of breaking strength and elongation on the nylon treated with additives showed that photodegradation of nylon was greatly affected by the treatment with additives. Among five additives used in this study, benzotriazole (702) was observed to have good protective effect against photodegradation of nylon throughout the irradiation period. And the two types of benzophenone (101 and 101S) were also found to have some protective action, whereas the other two additives (antioxidant (412S) and amine (612 NH)) have poor effect on the nylon. Photostabilizing effect of additives to nylon evaluated from the irradiation time to halve the initial strength (_T50) was found to be in the following decreasing order: 702<101S<101<612NH<(101+412S).