| 摘要 |
The present invention relates to an ethylene vinyl acetate copolymer (hereinafter, EVA) for an encapsulation material sheet of a solar cell and a method of preparing the same, and more particularly, to an EVA for an encapsulation material sheet of a solar cell, the EVA not having large neck-in during a solar sheet processing process and being able to reduce heat shrinkage of a sheet in a lamination process of a solar module, and to a method of preparing the same. For the purpose, according to the present invention, an EVA is characterized in that a vinyl acetate content in a resin rages from 25% to 33% by weight, Mz is 220,000g/mol or less, molecular weight distribution ranges from 3.5 to 4.5, melt index measured with a load of 2.16kg at 190°C is 6 to 35g/10min, and Tan δ value measured in a Rheometer at 100°C satisfies Formula 1, 1.85 * Ln(MI) / (0.72 * In(frequency) + 3.12) < Tan δ < 2.33 * Ln(MI) / (0.72 * In(frequency) + 2.81). |
