[in Japanese]

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SynopsisWe discussed the effects of honeycomb-like structure of the composite of boron nitride and phenol resin, on the thermal conductivity, by using various types of alkoxy silane and phenol resin particles. The thermal conductivity of the composite having the honeycomb-like structure was significantly larger than that with general dispersion state, in the range less than 70 volume content of boron nitride. Further, we discussed that the applicability of Maxwell-Eucken, Bruggeman, and our model to thermal conductivity of honeycomb-like composites. It was confirmed that our model was applicable, not only, to the thermal conductivity of the composite with general dispersion state, but also, to that having the honeycomblike structure, although the other models could not be used for predicting the thermal conductivity of the composite with honeycomb-like structure.

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SynopsisThe surface treatment of spherical silica particles using mixed silane coupling agents having di- and trialkoxy groups was carried out, and the molecular mobility of treated layer was analyzed using a 1H pulse NMR. The silane coupling agents used in this study have mercapto group as a functional group. In order to vary the amount of adsorbed silane on particle surface, the amount of silane added at surface treatment was set in the range from 1.5 to 7 times larger than that required for monolayer coverage. The relaxation time measured on the surface layer by a pulse NMR was longer for the dialkoxy structure than the trialkoxy structure. The relaxation time measured for the mixed silane-treated system increased with an increase of the dialkoxy silane content in the range of those for the dialkoxy and the trialkoxy structures. The tendency became more remarkable with an increase of the amount of adsorbed silane.

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SynopsisIn enhanced and horizontal recycling of FRP, Fiber Reinforced Plastics, which are very difficult to be recycled, optimization of alcohols used to develop shrinkage control effect as a low profile additive for FRP forming on styrenefumaric acid copolymer (SFC) was conducted. 1-octanol showed the highest performance. Scale-up of SFC separation and modification process using 1-octanol was tried and pilot plant was built. Pilot test demonstrated the extraction rate of 97% and the conversion of 75%, which are equivalent and 90% of bench test result in SFC separation process, respectively. The thickened modified SFC was successfully discharged from the vessel by adding methanol to reaction liquid. The obtained SFC was used to make an FRP sample board as recycled low profile additive (LPA) with styrene and tested comparing with a commercial LPA. The recycled LPA showed higher shrinkage control performance than the commercial LPA and met criteria for major quality items. Observation of the cross section, FRP sample board using the recycled LPA demonstrated many smaller voids than the one using the commercial LPA and they were uniformly dispersed.

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SynopsisInfluence of crosslinking density, bulkiness and rigidity of the main chain on the properties of the epoxy cured products was investigated. Incorporation of rigid structure i.e. 4,4’-biphenylene and 2,6-naphtylene moiety, in the backbone was effective for increasing fracture toughness and lowering thermal expansion, which was thought to depend on the large free volume fraction caused by the steric hindrance around crosslinking points. According to the above concept, polyfunctional epoxy resins containing rigid backbone were synthesized for industrial applications in consideration of increasing thermal property and moldability.

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[in Japanese]

View full abstract

[in Japanese]

View full abstract