To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under ...To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for preparing novolaks in a two-step manner, a divalent metal salt catalyzed novolak preparation followed by a strong acid catalyzed novolak preparation. The optimum conditions for the two-step procedure were determined by orthogonal experiment design. The results showed that it was easy to prepare fast curing novolaks with cure time in the range of 20 s to 30 s and softening point in the range of 80℃ to 90℃ under complex catalysis conditions.展开更多
The miscibility and phase behavior of the blends of polyoxymethylene (POM)/Novolak were investigated by the cloud point method, which showed that the POM/Novolak blends exhibited a lower critical solution temperature....The miscibility and phase behavior of the blends of polyoxymethylene (POM)/Novolak were investigated by the cloud point method, which showed that the POM/Novolak blends exhibited a lower critical solution temperature. The melting point of POM decreased when diluted with Novolak. From the melting temperature depression of POM, a negative interaction parameter (x) between POM and Novolak was obtained. The IR spectrum revealed that the miscibility between POM and Novolak was caused by the specific interaction between the OH groups of Novolak and the ether oxygen atoms of POM. The morphology of the blends investigated by polarized light microscopy showed that the size of spherulites of POM was sharply decreased by its mixing with Novolak. This suggests that Novolak be used as a compatibilizer for POM.展开更多
1 Results Imprint lithography[1] has attracted considerable attention from the viewpoint of low cost fabrication,because light exposure systems are not required. Up to now,polymethylmethacrylate (PMMA) films and hard ...1 Results Imprint lithography[1] has attracted considerable attention from the viewpoint of low cost fabrication,because light exposure systems are not required. Up to now,polymethylmethacrylate (PMMA) films and hard molds were often used in imprint lithography.In this paper,we report on the successful demonstration of imprint lithography using novolak resin (OFPR-800),which is more suitable than PMMA for dry etching,and a soft mold such as a soft polyester sheet,which has a two-dimensional (2D) square ...展开更多
文摘To save energy and raise molding and coremaking productivity, the synthetic procedure of novolaks for the shell process was investigated. The study indicated that it was difficult to obtain fast curing novolaks under strongly acidic conditions alone. A novel synthetic procedure was proposed for preparing novolaks in a two-step manner, a divalent metal salt catalyzed novolak preparation followed by a strong acid catalyzed novolak preparation. The optimum conditions for the two-step procedure were determined by orthogonal experiment design. The results showed that it was easy to prepare fast curing novolaks with cure time in the range of 20 s to 30 s and softening point in the range of 80℃ to 90℃ under complex catalysis conditions.
文摘The miscibility and phase behavior of the blends of polyoxymethylene (POM)/Novolak were investigated by the cloud point method, which showed that the POM/Novolak blends exhibited a lower critical solution temperature. The melting point of POM decreased when diluted with Novolak. From the melting temperature depression of POM, a negative interaction parameter (x) between POM and Novolak was obtained. The IR spectrum revealed that the miscibility between POM and Novolak was caused by the specific interaction between the OH groups of Novolak and the ether oxygen atoms of POM. The morphology of the blends investigated by polarized light microscopy showed that the size of spherulites of POM was sharply decreased by its mixing with Novolak. This suggests that Novolak be used as a compatibilizer for POM.
文摘1 Results Imprint lithography[1] has attracted considerable attention from the viewpoint of low cost fabrication,because light exposure systems are not required. Up to now,polymethylmethacrylate (PMMA) films and hard molds were often used in imprint lithography.In this paper,we report on the successful demonstration of imprint lithography using novolak resin (OFPR-800),which is more suitable than PMMA for dry etching,and a soft mold such as a soft polyester sheet,which has a two-dimensional (2D) square ...
