The fracture toughness and thermal shock resistance of an epoxy resin filled with alumina particles as a hard filler and CTBN rubber particles as a soft filler were investigated by focusing on the surface treatment of alumina particles. Although the fracture toughness was improved by filling alumina particles and CTBN rubber particles, the contribution of the alumina surface treatment to the fracture toughness was small. The thermal shock resistance was improved by filling CTBN rubber particles. However, the effect of alumina particles was not always positive. The thermal shock resistance is generally improved by the surface treatment of alumina particles : it was an example that the improvement was attained in the case of the brittle matrix epoxy resin regardless of the existence of CTBN. But on the other hand, the treatment was not effective in a tougher matrix resin. The fracture mechanisms were discussed, based on the fractographic observations.

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Shelf life stability and curability were evaluated for moisture curable epoxy resins using ketimines as a moisture latent hardener, derived from different kinds of ketones as their protective groups. Both the sheli life stability and curability of their epoxy resin compositions were influenced by the steric hindrance of ketimines. MIPK (methyl i-propyl ketone) and MTBK (methyl t-butyl ketone) having a specific structure with a narrow space <4.2Å around ketimine” N” and a wide space >3.7Å around ketimine” C” were demonstrated as the optimum starting ketones to ketimines. The lap shear strength as adhesive properties of the resins were higher using large volume ketones than those from small ones as the protective groups. These results may indicate that larger volume ketones formed by hydrolysis in their system would slow down the space in the curing of epoxy resins to a rate-determining level, and give less internal stresses on the adhesive surface. And their higher adhesive properties, obtained as another effect, were considered to be caused by a higher conversion in the reaction of epoxide using large volume ketones.

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The purpose of this study is to improve the flame-retardation of paper-base phenolic resin laminates without using halogen-or phosphor-containing flame retardants. Firstly, 2, 6-dimethylol-4-phenylphenol (DMPP) was synthesized from 4-phenylphenol and formaldehyde, then it was converted with benzoguanamine (BG) to a BG-modified phenolic resin (DMPP-BG). Structures and properties of DMPP and DMPP-BG were investigated with NMR, GPC and DSC. Secondly, DMPP-BG was blended with an ammonia resol in the DMPP-BG/resol ratio of 0/100-20/100 (wt/wt). The gelation time and curing temperature of DMPP-BG/resol blends (the DMPP-BG-modified phenolic resins) were almost the same as those of the resol itself. Paper-base DMPP-BG-modified phenolic resin laminates were prepared by compression molding, and gave superior results to the unmodified phenolic resin laminate in the flammability test by the UL94 vertical method : there was shown V-0 in the test results of the laminates from DMPP-BG/resol (?10/ 100) blends. The average burning rate of these laminates was about 1/10 times as low as those of the unmodified laminate. Also, the values indicating the performance of these laminates, such as oxygen index, electrical insulation and water resistance, were higher than those of the unmodified laminate.

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It is well known that vinyl monomers such as styrene and methyl methacrylate (MMA), cyclic ethers, and lactones undergo large shrinkage during polymerization. Further, network polymers such as epoxy resins, phenol resin, and unsaturated polyester undertake shrinkage on crosslinking, and this cause the big problem in the materialization.
We have already reported spiro ortho ester (SOE), spiro ortho carbonate (SOC), and bicyclo ortho ester (BOE) shows no shrinkage during cationic ring-opening polymerization.
In this article synthetic methods of vinyl monomers containing SOE, SOC, and BOE moieties are described, and polymers carrying SOE, SOC, and BOE structure as no shrinkage function in the side chain are synthesized by the their homopolymerization and copolymerization with vinyl monomers.
These polymers undergo cationic ring-opening polymerization to obtain the corresponding network polymers and showed no shrinkage during crosslinking.

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Polybenzoxazine is a recently developed resin whose structure is similar to traditional phenol resins. It has the same advantages as the traditional phenol resin in the thermal stability and non-flammability, in addition also having more advantages that are not found in the latter resins. A relatively high curing temperature and brittleness, however, are the disadvantages of this resin. This article showed methods to further enhance its specific properties. One method was the preparation of novel monomers that gave it improved properties upon cure : introduction of crosslink sites into the volatile components upon thermal degradation was remarkably effective to enhance high temperature properties. Another one was an alloying technique, which gave polybenzoxazine alloys with various properties depending on the counterpart. Introduction of nanolayered silicates resulting in an organic-inorganic nanocomposite was also effective for improving the performance.

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