Project/Area Number |
07555585
|
Research Category |
Grant-in-Aid for Scientific Research (A)
|
Allocation Type | Single-year Grants |
Section | 展開研究 |
Research Field |
有機工業化学
|
Research Institution | Kanagawa University |
Principal Investigator |
NAKAMURA Shigeo Kanagawa University Faculty of Engineering, Professor, 工学部, 教授 (10011008)
|
Co-Investigator(Kenkyū-buntansha) |
KAMAGATA Kazuo Nisshin Kaken, Director, 取締役
|
Project Period (FY) |
1995 – 1997
|
Project Status |
Completed (Fiscal Year 1997)
|
Budget Amount *help |
¥1,500,000 (Direct Cost: ¥1,500,000)
Fiscal Year 1997: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1996: ¥800,000 (Direct Cost: ¥800,000)
|
Keywords | Epoxy resin / Curing agent / Active ester / Internal active ester / Trimethylsilyl ester / Dielectric property / Mechanical property / Water absorption / フェノールノボラック / クレゾールノボラック / 吸水率 / ガラス転移温度 / 硬化剤 / 誘電的性質 / 吸水性 |
Research Abstract |
Epoxy resins without hydroxyl groups after curing are expected to have low water absorption and dielectric constant. They are desirable as high-performance electric and electronic materials. Therefore, various novel curing agents were developed for epoxy curing, and properties of cured resins such as mechanical and dielectric properties and water absorption were examined in detail. When esters of 1,3,5-trihydroxybenzene with carboxylic acids were used as trifunctional active esters, the reactivity for epoxy curing was decreased with the bulkiness of carboxylic acid residues. The glass transition temperature (Tg) shifts to lower temperatures with increasing length of alkyl chain of carboxylic acid residues but is shifted to higher temperatures by branching the alkyl moiety or incorporating a phenyl group into ester. The active esters as curing agents improve the water resistance and electric properties of cured resins because no hydroxyl groups are left after curing. However, the epoxy resins cured with active esters have lower Tg values compared to that cured with conventional curing agents. Therefore, novel multifunctional active esters with internal ester bonds were prepared and used as curing agents utilizing the insertion reaction of internal ester groups into epoxy groups. The Tg of cured resins were improved and the maximum value of 142゚C was attained. Trimethylsilyl ethers of phenol novolak and cresol novolak were used as curing agent, the Tg of cured resins was as low as 110゚C but the water absorption was decreased to 1/10 of that cured with conventional curing agents.
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