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Development of Epoxy Resins without Hydroxyl Groups in the Molecular Chain

分子链中不含羟基的环氧树脂的研制

基本信息

批准号：
07555585
负责人：
NAKAMURA Shigeo
金额：
$ 0.96万
依托单位：
Kanagawa University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (A)
财政年份：
1995
资助国家：
日本
起止时间：
1995 至 1997
项目状态：
已结题

项目摘要

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.

固化后不含羟基的环氧树脂预期具有低吸水性和介电常数。它们是理想的高性能电气和电子材料。因此，开发了各种新型固化剂用于环氧固化，并详细研究了固化树脂的性能，如机械性能、介电性能和吸水率。当使用1，3，5-三羟基苯与羧酸的酯作为三官能活性酯时，由于羧酸残基的庞大性，环氧固化的反应性降低。随着羧酸残基烷基链长度的增加，玻璃化转变温度（Tg）向低温方向移动，但通过烷基的支化或在酯中引入苯基，玻璃化转变温度向高温方向移动。活性酯作为固化剂，由于固化后不留下羟基，因此提高了固化树脂的耐水性和电性能。然而，与用常规固化剂固化的环氧树脂相比，用活性酯固化的环氧树脂具有较低的Tg值。因此，新型的多功能活性酯与内部酯键的制备和用作固化剂利用内部酯基团插入到环氧基团的反应。用三甲基硅醚酚醛清漆和甲酚酚醛清漆作固化剂，固化树脂的Tg可达1/10 ℃，而吸水率仅为常规固化剂的1/10。