An air drying, single component, acrylic base system suitable for general purpose coating of printed circuit assemblies. The cured coating is readily repairable. Also available in spray cans. Properties of Liquid HumiSeal
Density, (g/cm3) per ASTM, Meth. D1475: 0.90 ± 0.02
Solids Content, % by weight per Fed-Std-141, Meth.4044: 35 ± 2
Viscosity, centipoise per Fed-Std--141, Meth. 4287: 470 ± 20
Flashpoint, 0C per ASTM, Meth. D56: -1 (30)
VOC (grams / liter): 592
Drying Time to Handle per Fed-Std-141, Meth.4061: 10 minutes
Recommended Curing Conditions: 24 hrs @ rm. temp or 30 min.@ 76°C (1700F)
Time Required to Reach Optimum Properties: 7 days
Pot Life at Room Temperature: 12 months
Shelf Life at Room Temperature: 12 months
Properties of Cured HumiSeal Thermal Properties
Continuous Use Operating Range°C): -65°C to +125°C
Thermal Shock, per MIL-I-46058C: Passes
Solderability: Good
C oefficient of Thermal Expansion - DMA: 77ppm /°C
Glass Transition Temperature - TMA: 15°C
Young‘s Modulus - DMA: 10074psi
Physical Properties
Clarity: Transparent
Build per Dip, mils, per ASTM,Meth.D823: 2
Flexibility, per MIL-I-46058C: Fair
Adhesion, per ASTM, Meth. D2197: Excellent
Flammability, per ASTM, Meth. D635: Self-Extinguishing
Weather Resistance: Very Good
Electrical Properties
Dielectric Withstand Voltage, volts per MIL-I-46058C: >1,500
Dielectric Breakdown Voltage, volts, per ASTM, Meth. D149: 8000
Dielectric Constant, at 1MHz and 250C, per ASTM-D150-65T: 2.03
Dissipation Factor, at 1MHz and 250C, per ASTM-D150-65T: 0.01
Insulation Resistance, ohms, per MIL-I-46058C: 350 x 1012
Moisture Resistance, ohms, per MIL-I-46058C: 40 x 109
Chemical Properties
Main Constituent: Acrylic
Fungus Resistance, per ASTM-G21: Passes
Resistance to Chemicals: Fair Cleanliness of the substrate is of extreme importance for the successful application of a conformal
coating. Surfaces must be free of moisture, dirt, wax, grease and all other contaminants. Contamination
under the coating will cause problems, which may lead to assembly failures.
HumiSeal coatings may be applied by brush, dip or spray.
Dipping
Depending on the complexity, density and configuration of components on the assembly, it may be
necessary to reduce the viscosity of HumiSeal 1B15 with HumiSeal Thinner 503 in order to obtain
a uniform film. Once optimum viscosity is determined, a controlled rate of immersion and withdrawal (2 to
6" per minute) will further insure even deposition of the coating and ultimately a uniform film. During the
application, evaporation of solvent causes an increase in viscosity, which should be adjusted by adding
small amounts of Thinner 521. Viscosity in the dip tank should be regularly checked by the use of a
simple measuring device such as a Zahn or Ford viscosity cup.
Spraying
HumiSeal Type 1B15 can be sprayed using conventional spraying equipment. As a rule, the addition of
Thinner 521 is necessary to assure a uniform spray pattern resulting in pinhole free film. The amount of
thinner and spray pressure will depend on the specific type of spray equipment used. The spraying
should be done under an exhaust hood so that the vapour and mist are carried away from the operator.
The recommended ratio of HumiSeal Type 1B15 to HumiSeal Thinner 521 is 1 to 1 by volume, as a
starting point. The quantities may be adjusted to obtain a uniform coating.
Brushing
HumiSeal Type 1B15 may be brushed with a small addition of HumiSeal Thinner 503. Uniformity of the
film depends on component density and operator's technique.
Storage
HumiSeal Type 1B15 should be stored at room temperature, away from excessive heat, in tightly closed
containers. HumiSeal products may be stored at temperatures of -18°-38°C. Avoid direct sunlight. Prior
to use, allow the product to equilibrate for 24 hours at 18-32°C.
Caution
Liquid HumiSeal coatings are flammable. Do not use in presence of open flame or sparks. Avoid
inhalation of vapours or spray. Use only in well-ventilated areas. Avoid contact with skin and eyes. If
contact occurs, wash with soap and water. If swallowed, call physician immediately. Refer to MSDS
before use. |