The Modification Of C₅ Petroleum Resin Used In Hot Melt Pressure Sensitive Adhesive

In view of the problems of C5 petroleum resin produced in China having a high gardner colour, low softening point and high wax cloud point, it is not suitable as a tackifying resin used in hot melt adhesive and hot melt pressure sensitive adhesive. By investigating the research and development trends of petroleum resins in and out of the country, the catalyst-polymerization method was chosen to prepare the new type of C5 petroleum resin and the styrene and the isoamylene were chosen to adjust the propereties of the C5 petroleum resin.Firstly, the polarity and reduces the gardner colour of the petroleum resin were improved by the addition of styrene and by controlling the content and component of the solvent, the catalyst content and the polymerization temperature,the effect of adding styrene on decreasing the softening point was weakened. Finally, the best formulation and technical conditions of producing a high-grade C5 petrleum resins were obtained as follows: by adding 10wt% styrene, 100wt% solvent, 12wt% toluene, 2wt% catalyst and 0.5wt% antioxidation agent, a new kind of petroleum resin with the low gardner colour and high softening point were prepared at 55℃for 2h. The raw materials were added in 120 min. Secondly, the proportion of diolefin and olefin was adjusted by adding isoamylene. The results show that when the content of isoamylene is 15wt% and the content of styrene is 10wt%, the proportion of diolefin and olefin is 1.36:1. The resulting petroleum resin is with 92℃wax cloud point, 87.5℃softening point, Mz less than 5000 and the gardner colour less than 3. Comparing with the Korea product A-1100, C-1100 and American product E-2203LC, the results show that the propterties of the new petroleum resin are basically equal or close to the products as above. Finally, the new petroleum resin was used as tackifying resin to prepare SIS hot melt pressure sensitive adhesives. The tackifying effect of the resulting modified petroleum resin was compared with theTianLi resin WT-1288, A-1100 and E-2203LC. The result indicates that the modified petroleum resin has a good tackifying effects. It is better than the TianLi resin WT-1288 and basically close to the level of the same product in abroad. The climate-toerance is close to A-1100.