| Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
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| Research Abstract |
In this study, two kinds of expansible monomers, isophorone and trimethyl hexamethylene diisocyanate containing bicyclic ortho ester structures were synthesized, and various expansible composite resins, which had each expansible monomer/dilute monomers (triethylene glycol dimethacrylate and two mixtures (isophorone diisocyanate or trimethyl hexamethylene diisocyanate : hydroxyethyl methaerylate=2 : 1) ratio and trial microspherical filler with improved surface (75wt%) were prepared. The physical properties of various expansible composite resins were examined, and the following results were obtained.
1. In cases of two radical catalysts, tert-butyl peroxy maleic acid・N, N-dihydroxy ethyl-p-toluidine F1-cyclohexyl-5-ethyl barbituric acid-4-acryloxy ethyl trimellitic acid system (BMA catalyst) and benzoyl peroxide-N, N-dihydroxy ethyl-p-toluidine・1-benzyl-5-phenyl barbituric acid・4-acryloxy ethyl trimellitic acid anhydride system (BPO catalyst), setting time of expansible composite resins were tended to behind time and to decrease compressive and tensile strength in proportion to increase additive volume (more than 20wt%) of expansible monomer respectively. Therefore, their composite resins had not been become practicable.
2. In case of BMA catalyst, composite resins with two expansible monomers (range from 5 to 20 wt%) were tended to behind time and to decrease compressive and tensile strength. However, in case of BPO catalyst, their composite resins had been same setting time and maximum values of compressive and tensile strength of composite resins with expansible monomers (5 or 10 wt%) respectively.
In the future, it is necessary that new kinds and additive volume of expansible monomers, catalysts and accelerator are investigated, in order that expansible composite resins become practicable.
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