Silicone Conformal Coating
◇Low viscosity solvent-based type
◇Easy to spray, dip, brush or flow coating
◇Room temperature cure or fast heat-cure with additional catalysts
◇Strong adhesion
◇Stable and flexible at temperature ranging from -60℃(-76°F)to +200℃ (392°F)
◇Fluoresce when exposed to UV
◇Excellent insulating property

These products for applying to assembled functional circuit boards in the ways of dipping, brushing or spraying to form a surface protection film, functions of which include moistureproofness , rot-and chemical and insulation protections, etc, so that the circuit boards can protected well; and moreover, the work will not be suffered and signals will not be affected even in extremely poor working environments. They are especially suitable for hybrid IC base boards, electronic control panels, communications circuit boards, aviation instrument panels, flexible printed circuits and microcomputer-controlled panels, etc.

Type KQ2577
Color Transparent
Non-volatile Content(%) ≥ 70
Specific Gravity at23 ℃ (73.4°F) 1.10±0.05
Viscosity (mpa ' s) 180±20
Physical properties, cured 24 hrs at 23 ℃ ( 73.4°F) or 30 mins at80℃(176°F)
Hardness Durometer D ≥22
Tensile Strength (mpa) ≥3.0
Elongation at Break (%) ≥35
Electrical properties, cured 24 hrs at 23 ℃ ( 73.4°F) or 30 mins at80℃(176°F)
Dielectric Strength (kv/mm) ≥18
Dielectric Constant (100Hz) ≤ 2.76
Dielectric loss Factor (100Hz) ≤0.004
Volume Resistivity ( Ω .cm) ≥0.5 × 10 14

【Handing Precautions】
For best adhesive effect, the surface to be coated with KQ2577 Conformal Coating must be clean and dry before being applied .KQ2577 Conformal Coating has excellent adhesion on clean boards under most circumstances. Any stronger adhesive effect required , the use of KQ5 primer is recommended.

【Directions for usage】
KQ2577 Conformal Coating can be applied by means of spraying, dipping, brushing or flow coating. Use a hand-held spray gun for few sprayings and dilute the coating to a 40% solid-content concentration by using aromatic anhydrous solvent (i.e. xylene or toluene); when an automatic spraying device is used, dilute the coating to 50% solid-content concentration by using PMA (propylene glycol methyl ether acetate). Mixed solution of which should be completely used within 5 days. One dip coat of KQ2577 Conformal Coating typically produces a film thickness of 0.1 to 0.2mm. Thinner coatings can be achieved KQ2577 Conformal Coating with dry xylene or toluene. It is recommended that dip coating speed is approximately 30cm per minute.

Conformal coating can be cured either at room temperature or heat cure at 70℃ to 100℃. Catalyst could be added in to accelerate the curing process.

【Room temperature cure-without catalysts】
KQ2577 Conformal Coating is cured at room temperature by reacting to moisture in the air, and a 0.1mm thickness’ coating will be tack-free in 15 to 30 minutes. Handling and in-process storages are allowed and complete curing time is 72 hours later after coating. 23℃ (73.4°F)/50% RH is recommended. Generally, curing speed will accelerate as the temperature and humidity rise.

【Heat cure-without catalysts】
Curing time could be shortened by heating. When heating, enough time should be left to make solvent fully volatilized in the air circulating oven. Generally, it takes 10 minutes for a 0.1mm thickness’ coating to volatilize at room temperature and cure in 10 minutes at the temperature of 80℃ (176°F). If the coating is distorted or effervescent, it is considerable to set apart more time for the solvent to volatilize better at room temperature before heating. The thicker the coating, the longer the curing time would be. Cracks may occur on the coating if it is exposed to low temperatures before curing. Circuit boards coated with KQ2577 Conformal Coating should be cured at 80℃(176°F) for 10 minutes and left at room temperature for at least 6 hours, and then could be used in the cold endurance experiment or shipped in cold weather. Otherwise, they should be left at room temperature for 48 hours before shipping in cold weather. The curing time could be shortened by heating for a longer period of time and at a higher temperature.

【Cure-with catalysts】
When applying thick films (>0.25mm) of KQ2577 Conformal Coating, the use of KQ series Catalysts will shorten the tack-free time; for example, a tack-free time would be about 70 minutes for a 0.4mm thickness film coating at 23℃(73.4°F)/60% RH without catalyst; while under the same condition, the tack-free time will be shortened to 45 minutes when catalysts are used. The use of KQ series Catalysts will improve solvent resistance of materials when the coating generates solvent vapor. The catalyst can shorten the storage period of the material so that the method of dipping is not proposed. The pot life for mixtures of KQ2577 Conformal Coating with other catalyst is 7 days if they are stored in an airproof tank at room temperature. Use 0.5 parts of KQ series Catalyst to 100 parts by weight or KQ2577 Conformal Coating as supplied. A catalyst is being used to improve solvent resistance of the coating which should be exposed to 80℃(176°F) for 30 minutes. Set apart sufficient time for solvent evaporation prior to exposure to higher temperatures.

【Pot life】
For longest pot life, all moisture be kept out. Please pay attention to proper handing. The tank should be sealed when not used. If it has not been used for several days, a thin layer of aromatic anhydrous solvent (such as xylene) should be added onto the surface in order to keep moisture out. In addition, a crust on the tank surface should be removed first if there were any. Containers that are partially filled with coating should be sealed and filled with dry gas in the upper tank space if possible. When diluting, the use of reactive solvents (i.e. alcohol or hydrosolvent) will shorten the storage period. The mixture of KQ2577 Conformal Coating and PMA, which are used to automatic spraying devices, should be kept no longer than 5 days.

【Flame Resistance】
KQ2577 Conformal Coating has been passed the tests of flame resistance on printed circuit boards of ANSI FR-4, FR-5, G-10, G-11, GEM-1 and GEM-3.

【Handing Precautions】
Please read the product safety instructions and labels on the tank carefully regarding safe use, physical or health hazards. Ask sales representative for the instruction book..

【Storage and shelf life】
The shelf is 24 months from the date of manufacture if stored an airproof container at or below 25℃(77°F). Precautions must be taken to keep out all the moisture.