As we proceeded with the development of a novolac resin with flexibility and high lithography performance, we focused on adopting a linear polymer structure with few branched structures as used in a dry film resist. BisC/BMMB and (BisC/PY)/BMMB novolac resins with 2,2-bis (4-hydroxy-3-methylphenyl) propane (BisC) and/or a mixture of BisC and pyrogallol (PY) as the PhOH component and 4,4'-bis(methoxymethyl)-1,1'-biphenyl (BMMA) as the comonomer, i.e., novolac resins with bulky isopropylidene groups and rigid BMMB components in the molecular chain backbone, were studied. For both novolac resins, the Mw increased as the molar ratio of BMMB component increased. Though the maximum Mw of BisC/BMMB and (BisC/PY)/BMMB novolac resin soluble in aqueous alkaline solution was approximately 1500 and 3800, respectively, and the both dissolving rate for alkaline aqueous solutions (DR) were showed relatively slow, 0.03> (Å/s). BisC/Form and PY/BMMB novolac resins having liner polymer structure also investigate. The order of flexibility including them were BisC/BMMB novolac resin < (BisC/PY)/BMMB novolac resin≒BisC/Form novolac resin < PY/BMMB novolac resin. The difference in the flexibility of these novolac resins was found to be largely due to the formation of intramolecular hydrogen bonds. Both of BisC/BMMB and (BisC/PY)/BMMB novolac resins did not show good lithography ability.
We investigated an influence of a base catalyst to form the porous structure of resorcinol－formaldehyde (RF) cryogel. The pore size depends on the number density and the growth rate of the cluster consisting of RF oligomers. To reveal the role of the base catalyst in the reaction schemes of the RF oligomer formation, the elimination reaction of a hydroxy group was extracted as the key reaction by the UV-visible absorption analysis. The quantum mechanical calculations estimated that the polymerization process was hindered by the activation barriers related to the heat of formation. Therefore, the generation rate of the oligomer was influenced by the reactivity of the elimination reaction. According to the calculation results, the differences in the heats of formation were caused by the types of cation. In comparison with the generated structures using the corresponding base catalysts, we found that pore sizes increases with heats of formaition in the elimination reaction.
Solvent soluble branched Amide-Imide resin was successfully synthesized from isocyanurates and anhydrides. This Amide-Imide resin is soluble in general organic solvents. This branched Amide-Imide resin has carboxylic groups, which is curable with epoxy resins, and the cured products showed excellent thermal resistance and high Tg. Aliphatic AmideImide resin is colorless and has excellent yellowing resistance. This Amide-Imide resin has various structures introduced at the terminal. The photo-polymerizable amide imide resin has excellent heat resistance, photosensitivity and developability. And it is suitable for photoresist material. The active-ester terminated Amide-Imide resin has excellent heat resistance and dielectric properties.
High performance epoxy resin is required by advancement of functional material field. As a measure for this purpose, incorporation of polycyclic aromatic unit having 2 to 4 rings into the epoxy resin structure was investigated. The rigid and hydrophobic structure have improved heat resistance, moisture resistance and low thermal expansion, as well as improved flame retardancy due to their high thermal decomposition stability. It was also confirmed that introducing rigid rod-like skeleton such as 4,4’-biphenylene group into the main chain is effective for increasing Tg and fracture toughness.Incorporation of polycyclic aromatic unit into resin structure is considered to be one of the leading methods for improving properties of epoxy resins.