| 摘要 |
<p>Light-selective thermoplastic sheets and films containing (a) a thermoplastic such as PVC, polethylene, polymethyl methacrylate, ethylene/vinyl acetate copolymers, polyamides etc., (b) light- and heat-stabilisers (c) one or more dyestufs in type and quantity such that the absorption spectrum of the composition shows minimum transmission between 3800 and 5900 angstroms, a transmission greater than 50% between 6300 and 6600 angstroms, and optionally (d) U.V. absorber(s), (e) plasticiser(s) and (f) lubricant(s). Uses are in agriculture for protection and forcing of plants, flowers, fruits. Compositions showing minimum transmission in the ranges 4100-4500 angstroms, 4900 - 5400 angstroms and 5250-5750 angstroms.</p> |
