Synthesis And Characterization Of The Silicone Material Used For LED Encaosulation

The anionic and cationic open ring polymerization were used in this thesis, and the LED encapsulation basic polymer and crosslink agent which had great optical and thermal properties were synthesized via solvent method, and with the existence of high performance platinum catalyst, the vulcanization in the macromolecular and (?)molecular crosslink agent1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane system and its influential factors were studied, and came to the conclusion that:1. The blocking agent and the catalyst had a little influence on the refractive index of the products and the latter was influenced mainly by the molar content of the MePhSiO-segment. Through the method used solvent, methyl phenyl vinyl silicone oil which refractive index reached1.5502was got, and the influence factors were discussed. The solvent had impacts on the system, and through the experiment optimization, the solvent reached40%weight of the whole monomer was an appropriate comsumption, and the products with great thermal and optical properties were got, and were hopefully applied as the based material in the LED encapsulation.2. In order to get the transparent high molecular crosslink agent-methyl phenyl hydrogen silicone oil in the solvent method, the MePhSiO-segment must reach45mole%. The proper catalyst is trifluoromethyl sulfonic acid cation exchange resin was found. The results showed the proper catalyst dosage was5%～7%weights of the whole ring monomers. In addition, the blocking agent had a little influence on the refractive index; the latter was mainly depended on the MePhSiO-segment. Through the experiments we synthesized the phenyl hydrogen silicone oil which transmittance more than90%, refractive index higher than1.5000in the visible light range and had well optical and thermal properties, which was hopefully applied as a cross-linking agent of LED silicone encapsulation.3. It was found that the linear methyl phenyl vinyl silicone oil had a higher vulcanization temperature and longer time than the branched one. The experiments results also demonstrated that via the addition of the silicone resin, the vulcanization products with hardness of40D-50D, well transmittance, high refractive index, excellent water resistance and yellowing resistance could be synthetized, which was hopefully applied as the LED encapsulation silicone material.4. In the existence of the high efficient additional catalyst platinum complex with divinyl tetramethyl disiloxane, branched methyl phenyl vinyl silicone oil/methyl phenyl vinyl silicone resin and molecular crosslink agent, the vulcanization used for LED encapsulation in this condition were studied. To the system TMDPTS, methyl phenyl vinyl silicone oil and/or methyl phenyl vinyl silicone resin, the vulcanization temperature goes higher the vulcanization time gets shorter, only if the vulcanization completed, the temperature had little influence on the vulcanization products. The content of vinyl goes higher, the hardness of the products gets better, so as the thermal properties. In addition, we got a series of vulcanization products with high refractive index (>1.5300), high transmittance (>90%), great thermal properties, moisture-resistance and yellow-resistance, which was hopefully applied as the LED encapsulation silicone material.