Junji Mukai

New heat resistant solventless varnish “10 resin” (part II)

The research and development of organic heat resistant materials has made a great progress especially in the field of solvent type varnishes. For example, polyimide, polybenzimidazole, polydiphenylether, and silicone have been developed so far. However, solventless varnishes that can resist high temperatures have not been developed yet, because it is very difficult to give high temperature heat resistant properties to cured resins which have a low viscosity before curing. Epoxy resins are now widely used as solventless varnishes, however, they cannot be used at temperatures above 180°C.

New heat resistant “DP resin”

The cost of electrical equipments can be lowered by reducing the size and weight of the equipment. This has led to the need for the development of inexpensive heat resistant polymers having high mechanical strength at elevated temperatures.

New rubberlike resins for casting and impregnation

Typical properties were evaluated on a newly developed rubber-like resins. The properties illustrated are: 1. viscosity and cure schedules adjustable to meet specific requirement, 2. good tensile and electrical properties, 3. good retention of tensile properties on long-term exposure at 130°C, 4. high resistance to severe thermal shock, 5. excellent resistance to water.