| Because of the entangling-free and unique three dimensional molecular structures, low viscosity, high solubility in common organic solvents and high chemical reactivity, hyperbranched polymer has been considered as the best resin for UV curable application. Enhancing the reactivity toward photopolymerization and increasing mechanic property are the key issues for designing new hyperbranched photopolymer.Hyperbranched polyesters (HBP) modified with epoxy resin were synthesized by the "one-step" ring opening polymerization of trimellitic anhydride (TMA) and epichlorohydrin (ECH), with bisphenol F (BPF) epoxy resin as the core. The polyesters were functionalized with grycidol methacrylate (GMA) to introduce acryloxy groups. Including BFE into the HBP not only increased the degree of branching, reducing the dispersity of molecular weight distribution for the HBP, but also made use of the excellent thermo-, mechanic, low water absorption and electric properties of BFE for HBP. The structures and properties of these polymers were characterized by FTIR, H1NMR, GPC, UV, VOP, Photo-DSC and TGA. It was found that viscosity of the hyperbranched polyesters increased with the fraction of BFE and then decreased down when further increase of BFE fraction. Introducing of BFE increased thermal stability, mechanical strength, enhanced the adhesion and photoreactivity for the modified photocurable HBP.Photoresists were prepared with the modified HBPs. The photo chemical and photo image property were studied. Using the modified HBPs, the initial gelling time decreased 4s, and the contrastγgel increased from 0.240 to 0.653. High sensitivity and high contract were realized. Clear etching patterns in micrometer size with smoothly surface were prepared with the photoresists.
|
PDF Full Text Request