VA177HV Air drying varnish
Product based on vinyl resin with excellent resistance to moisture, solvents, lubricants, an corrosive agents with very good dielectric properties.
It is normally used on metallic part, and in particular as protective for printed circuit boards where fungus resistance and fast tack-free time are required.
The film, after drying, has good flexibility in a temperature range from -30℃ until 140℃. This product is available also in spray can, code VA177S
Physical properties
Viscosity F/4 at 25℃ 40''~50''
Flash point (tag closed) -4℃
Specific gravity 930±10
Color Clear
Reducing Thinner D103
Tack-free time 5’
Complete cure at 25℃ 4 hours
Adhesion on metal very good
Chemical Properties
Salt spray resistance very good
Acid and alkali resistance very good
Mineral oil resistance very good
Thermal class
Twisted pair （ASTM3251） 130℃
Helical coil （ASTM3145） 130℃
Bond strength （ASTMD2519－68）
Helical coil, double reversed dip, 2 hrs at 150℃
Test temperature ℃ 25℃ 100℃
Bond strength Kg 5 2
Electrical properties
Sample preparation and conditioning conform to ASTM standard. Initial cure 2 hrs at 150℃
Dielectric breakdown voltage（ASTM D115） (film thickness：40μm)
As made 4500V
After 24 hours immersion in water 4000V
Volume resistivity （ASTM D257）
As made 1014Ω×cm
After 24 hours immersion in water 1011Ω×cm
Surface resistivity （ASTM D257）
As made 108Ω
After 24 hours immersion in water 108Ω
25℃ 100℃ 180℃
Dielectric constant （1Khz） 2.0 2.3 2.9
Dissipation factor （1Khz） 0.007 0.03 0.20
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