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The individuals of tertiary amines, including imidazole (1-amine), 1,2-dimethylimidazole (2-amine), 2,4,6-tris(dimethylamino-methyl)phenol (3-amine), 1-methylimidazole (4-amine), and 2-methylimidazole (5-amine), were added into UV-curable epoxide resins, respectively, and the effects on UV/thermal conversions, thermal properties and adhesion strengths for various types of substrates were investigated. According to the experimental results, the extent of effects of amines on physical properties was found in the order of: 3-amine > 4-amine > 1-amine > 2-amine > 5-amine. The resin with 3-amine exhibited the highest glass transition temperature ( T g = 72.3 °C) value and the lowest coefficient of thermal expansion (CTE = 70.8 ppm/°C), which also exhibited the highest adhesion strengths on various substrates, on glass (greater than 199 kg/cm 2 ), ITO (greater than 182 kg/cm 2 ), PET (115 kg/cm 2 ), and stainless steel (232 kg/cm 2 ), and possesses great potentials for advanced opto-electronic applications.

The work reported demonstrates that the yellowness of UV-curable epoxide resins can be improved by adding certain tertiary amines in appropriately determined amounts. According to the results of our experiments, 2.0 wt% benzoyl peroxide added to a resin effectively enhances the crosslinking density, and phenolic free radicals are produced during UV curing, which consequently induce yellowness via the reaction of oxygen and the free radicals. Imidazole (1-amine) and tertiary amines, including 1,2-dimethylimidazole (2-amine), 2,4,6- tris(dimethylaminomethyl)phenol (3-amine), 1-methylimidazole (4-amine) and 2-methylimidazole (5-amine), were chosen to be added to resins, and their effects on UV conversion and yellowness were investigated. According to the experimental results, tertiary amines in the resin can provide a certain degree of improvement in yellowness index (� YI) and color parameter (� E ∗ ab) of the resin sample. Whatever the type of tertiary amine, it is found that the optimum content of amine in resin is 1.0 wt%. Also, among the studied amines, the 3-amine exhibits the highest UV reactivity and the best efficiency for yellowness improvement with values ofa ∗ , � b ∗ , � YI andE ∗ ab as low as −1.4, 6.23, 11.27 and 6.48, respectively.  2007 Society of Chemical Industry

This work studies the effects of the monomer types, the number of hydroxyl functional groups (–OH) on polyol monomers, and the equivalent weight ratio of dicycloaliphatic epoxide to polyol for cationic polymerization (the R value) on the adhesion strength of UV-curable epoxy resins applied to organic light-emitting device (OLED) packaging. It was found that the volume shrinkage of resins after UV curing is related to the crosslinking density of the resin. The smallest volume shrinkage implied the highest adhesion strength of resin on glass substrate since the internal stress was minimized. This study observed that the resin containing polyol monomer is able to achieve the smallest degree of shrinkage (1.72%) and the highest adhesion strength (153.35 kg/cm 2 ) on glass substrate.

Preparation and property characterization of encapsulation resin contained hexagonal boron nitride (hBN) as inorganic filler were carried out in this work. The dielectric properties, coefficient of thermal expansion (CTE), thermal conductivity, curing kinetics, adhesion strength and viscosity of the resins with the load of hBN filler ranging from 9.2 to 25.7 vol.% (20–70 wt.%) were evaluated. It was found that the dielectric properties of resin containing SiO2 filler are inferior to that containing hBN. Also, the resins possessed lower CTE and the higher T g when the hBN contents were high (>15 vol.%) and the resin containing 25.7 vol.% hBN exhibited the largest thermal conductivity of 1.08 W/m K. Adhesion strength of the composite resins decreased with increase of hBN content and the adhesion strength on various substrates was found to be in the order of: alumina > Si wafer > eutectic PbSn solder.