An novel epoxy resin containing xanthene skeletons with hexamethyl groups and phenyl group as the substituting groups was synthesized. It was found that this epoxy resin could meet most of all requirements, 'Excellent flame retardancy',''High heat resistance','Low moisture adsorption' and 'Low dielectric constant / dissipation factor'. The performance showing them at the same time had never been obtained from conventional epoxy resins in the advanced electronics application fields. The result was considered as follows : the xanthene skeleton reinforced by the specialty substituting groups', having functions of accelerating char forming and enhancing steric hindrance, contributed to its high performance.
This epoxy resin was expected to promote the development of the environment friendly materials with high performance.

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Two types of alkyl phenols having different alkyl chain lengths (ethyl phenol and dodecyl phenol) were mixed, for the purpose of obtaining a new acceleration reagent to replace nonyl phenol acknowledged as an endocrine disruptor. The mixing ratio was determined so that the carbon number of the alkyl chain in the mixed alkyl phenols was equal to that in nonyl phenol. The acceleration effect and property of the mixed alkyl phenol system were investigated comparing with that of the nonyl phenol system. As a result, it was clarified that the mixed alkyl phenol system showed almost the same accelerating and plasticizing effects as the nonyl phenol system. Moreover, when a diluted reagent was added to the mixed alkyl phenol system, an ultimate strain of the resin in the tensile test was shown to be larger than that of the nonyl phenol system.

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Analytical theory of gelation has been extended so that intramolecular ring formation system and substitution effect in nonequilibrium polycondensation system can be formulated by rational probability generating function (pgf). The pgf of the extended cascade theory formulates these complex systems by regarding a polymer as a rooted graph and by applying Markov chain to the quasi-order among the parts in'treedecomposition'of the graph; a polymer system is expressed by the selection of parts and by the rules of their connections. Statistical amounts such as an average degree of polymerization and a critical point of gelation are obtained by routine calculation. The molecular mass distribution is evaluated by direct recurring calculations with a cutoff in the original pgf or in the Groebner base. As typical examples, there were given the formulation of local ring formation in tetra-functional unit system and that of first shell substitution effect in tri-functional unit system. Since the presented theory enables us to describe complex systems and to calculate within a reasonable time, the formulation is useful to analyze various type of experimental data of gelation.

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Epoxy resins of bisphenol A type cured with alkylamines having an alkoxysilyl group, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane (S320) and 3-aminopropyl-trimethoxysilane (S330) were prepared and their thermal /mechanical properties were analyzed by means of thermogravimetry, differential scanning calorimetry and dynamic viscoelasticity measurement. From the comparison of these properties with those of the resin cured with an ordinary amine agent, B002, it was revealed that the crosslinking reaction took place by hydrolysis of the alkoxysilyl group followed by condensation reaction resulting in the formation of siloxane linkage, together with the cuing of epoxy resin with amine.The thermal treatment at temperatures higher than 100°C was shown to be required for the formation of siloxane crosslinking.

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Phenolic resins have been widely used as hardeners for epoxy molding compounds in electronic applications, because of their good thermal, mechanical, and electronic properties. Conventional phenolic resins such as phenol novolac, however, often cannot meet the strict requirements in advanced microelectronic applications. Therefore developments of high performance phenolic hardeners are required. Incorporation of poly-nuclear aromatic structure, such as a naphthalene skeleton, into a resin backbone was investigated. The naphthalene-containing resin had lower viscosity in comparison with benzene ring based one at a same softening point.
It was also shown that naphthalene based resin had higher glass transition temperature (Tg) in a thermoplastic stage, and that cured polymers obtained from the naphthalene based resins had higher Tg than those from benzene based ones, in addition to lower moisture absorption and thermal expansion. Moreover, the naphthalene based resins showed excellent thermal stabilities, which seemed to cause the resins to have higher flame-retarding properties.

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In 1980s p henolic composites began to examined from the standpoint of fire safety. At the beginning, the market for phenilic composites was expect to expand quickly. Subsequently, however, its growth was slowed down under the influence of inter national economic depression and cost problems, etc. FRP demand for vehicles tends to change a lot by the fire accident of the subway in Daegu, Korea on February 18, 2003. RE-examination of materials for railroad vehicles has begun from the standpoint of safety, and BS-6365 standard is now becoming mainstream for testing the materials. In addition, the requirement for the materials such as safety, lightweight, noiseless and absorption of vibration, have become much more severe according to improving the speed of vehicles.
Internationalization in the molding techniques of phenolic composites have progressed, and development of their large-sized products are actively performed using autoclave and RTM methods. At the same time, the base in hand lay up production, in which labor occupies the high ratio of costs, is currently moving to China and the other Asian countries where labor costs are low. It is not too much, for FRP molders in Japan, to say that the key is whether they have the power or ability of product-proposal and development, for surviving as well as further growing up.

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