A detailed investigation on the curing reaction of maleimide resin in the presence of epoxy resin was conducted using model compounds. Selecting N-phenylmaleimide (PMI), phenyl glycidyl ether (PGE), N, N'-diphenylaspartimide (API) and aniline (AN) as model compounds, the reactions of PMI/PGE/API, PMI/PGE/AN systems were investigated. Without catalyst, the main reaction was the addition reaction of AN to PGE and PMI reacted a little. In 2-ethyl-4-methylimidazole (2E4MZ) catalyst system, the main reactions were the polymerization of PMI and the addition reaction of AN to PGE. When epoxy resin existed, the polymerization reaction of PMI was accelerated.

View full abstract

We investigated a powder coating made from polyester and acrylic resin. As a result, we have found that polyester-acrylic hybrid resin (hereinafter abbreviated as hybrid resin) which is composed of the two resins and copolymer formed by reaction of resins shows the characters of each resin.
In this paper, the film morphlogy and properties in relation to the copolymer content was discussed by a comparison between blend of the two resins and hybrid resin. The copolymer content was examined with a ¹³C NMR and film morphology was observed with a transmission electron microscope.
Change in morphology and compatibility, caused by the formation of copolymer, was observed.
The film consists of two layers, that is, the surface layer is composed of acrylic resin and the inner layer showing phase separation structure. If the content is appropriate, brittle acrylic resin is dispersed as small domain in polyester matrix. Then the film shows improved toughness and good surface properties owing to the surface layer. On the other hand, if the content is excess, the phase separation structure is unstable to deteriorate the above properties.

View full abstract

Epoxy resin compounds have some specific characteristics, such as excellent adhesive and mechanical strength. Therefore they are commonly used in the field of civil engineering as adhesives for concrete without any supporting structural materials. : for example, injection materials for repairing concrete cracks, adhesives for joining concrete blocks, and coating materials for protecting concrete from harmful chemicals.
The present article describes the use of epoxy resin compounds, mainly in the concrete engineering field, and attention points to be paid are also mentioned.

View full abstract

Thermoset composites are becoming more and more popular not only in aerospace but also in automotive application. This report summarizes Dow's resins for aerospace and the recent development of epoxy composites for automotive by using Resin Transfer Molding (RTM) process.
Epoxy composites made by RTM method can be used for the horizontal outer panel for automotive. This is because the part has smooth surface, good heat resistance and etc.

View full abstract

Production of the printed circuit board in Japan has increased with the increase of the electronic parts for electronic instruments and ICs, and its total sales in 1988 reached 800 billion yen.
The shapes and necessary properties of printed circuit boards have varied with the parts mounting technology, especially with recent developments of the surface mounting technology.
Corresponding to high density mounting technology, the printed circuit board is increasingly required to provide fine circuits, small-diameter through-holes and multilayer structure. Furthermore, it is also required to have a good thermal emission property, electromegnetic interference shield effect, high speed signal transmission and coefficients of thermal expansion adjusted to that of mounted parts.
This paper reviews necessary properties and development of printed circuit boards as well as prepregs of mainly epoxy resin copperclad laminates, in accordance with development of the surface mounting technology.

View full abstract

Ammonia and caustic soda are compared as catalyst of phenol-formaldehyde reaction. If ammonia is used, formaldehyde enters the bezene ring only in the position ortho of phenolic hydroxyl group. But in the case of caustic soda the ratio of ortho to para position is about 1 : 0. 6. Introducing the famous article of M. M. Sprung (1941), the present author wrote some memoranda concerning the difference of those two typical catalysts. Lastly introducing the article of P. W. Kopf and E. R. Wagner (1973) the chemistry of the intermediates of ammonia catalyst reaction was discussed and it became clear that Japan was ahead of other country in that field, because already during 1925-1953 all three intermediates i. e. dibenzylamine, tribenzylemine and benzoxazine were extracted from the reaction mixture and identified.

View full abstract