BOPP薄膜专用T 38 F型聚丙烯树脂的质量改进及结构性能分析

分析了中国石油兰州石化公司30万t/a聚丙烯(PP)装置生产的双向拉伸聚丙烯(BOPP)薄膜专用料(牌号为T38 F)存在加工尺寸稳定性较差、频繁破膜、成膜速度低、雾度高等质量问题的原因,还结合装置特点优化并调整了生产工艺条件。结果表明,相对分子质量分布宽、等规度高、等规度分布不均匀是造成T 38 F树脂存在相关加工质量问题的原因;采取调整一、二环氢气浓度,一、二环淤浆密度,降低m(三乙基铝)/m(给电子体)等措施后,T 38 F的加工性能获得改善,生产厚度大于12μm的BOPP薄膜时线速度可超过400 m/min且无破膜现象,制成BOPP薄膜的厚度偏差稳定在0.8%~1.2%,雾度由1.5%~2.0%降低到0.8%~1.2%。

Quality improvement and structure and property analysis of T 38 F polypropylene specialty resin for biaxially oriented polypropylene film

The problems in quality, such as poor processing dimensional stability, frequently film breaking, low film forming speed and high haze, were analyzed for T 38 F specialty polypropylene （PP） resin which was used for biaxially oriented PP （BOPP）film and produced by a 300 kt/a PP unit in Lanzhou Petrochemical Company of PetroChina. And based on the above mentioned analysis,the process conditions were optimized and regulated in accord ance with the unit characters. The results showed that the quality problems existed in T 38 F product were attributed to its broader molecular weight distribution, higher isotacticity, and uneven isotacticity distribution. By adjusting the hydrogen concentration and the slurry density in the first and the second re actors and reducing m （TEAL）/m （ Donor）, the pro cessability of T 38 F was improved, no film breaking occurred for 2 μm BOPP film at linear velocity more than 400 m/min. The deviation in thickness of ob tained film stably ranged in 0.8% -1.2% ,and haze decreased from 1.5%- 2.0% to 0.8% - 1.2%.