Summary: | 碩士 === 長庚大學 === 化工與材料工程研究所 === 94 === Promote Taiwan's color imaging industry to become the world's largest supplier of TFT displays that is an important issue in economical development. Liquid Crystal Displayer(LCD) is one important item in this industries. Diffuser is one of important component in LCD. In general, the Diffuser is made by one thin film and coating one layer of Polymethyl Methacrylate(PMMA) particle on two sides to let light scattering uniform. The price of PMMA particle for diffuser is higher tenfold than that of PMMA for usual use. The PMMA particle for LCD diffuser is specified on 5-30μm. In this study, we investegate the use of supercritical CO2 as anti-solvent in PMMA/THF(tetrahydrofuran) solution system to manufacture PMMA particle. In order to determine the pressure-volume expansion-temperature behavior of the tetrahydrofuran/supercritical CO2, the modified Peng-Robison equation of state was used. A novel experimental apparatus, which is involving, view window and stirrer has been used to carry out the study. The PMMA powder can be obtained by controlling the operation factors such as pressure, temperature, concentration, pressurized rate, pressure release rate, etc.
Learnt by the experimental result, we can obtain the PMMA microparticles with diameter 1-23μm by Supercritical Anti-solvent Method under 2000psi, 323K, 0.1wt%, and shorter time for evaluated pressure will help to produce the small particle.
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