P R O D U C T I N F O R M A T I O N
Information about Dow Corning® brand
Silicone Encapsulants
Two-Part Silicone Elastomers
Type
Elastomers
Physical Form
Two-part silicone elastomers
Special Properties
Flowable liquid; cures to exible elastomer; constant cure rate,
regardless of sectional thickness or degree of connement; service
range of -45 to 200°C (-49 to 392°F); no post cure required
Potential Uses
Protection of electrical/electronic devices
Silicones and Electronics
Long-term, reliable protection of sensitive circuits and compo-
nents is becoming more important in many of today’s delicate and
demanding electronic applications. Silicones function as durable
dielectric insulation, as barriers against environmental contam-
inants and as stress-relieving shock and vibration absorbers over a
wide temperature and humidity range.
In addition to sustaining their physical and electrical properties
over a broad range of operating conditions, silicones are resistant
to ozone and ultraviolet degradation, have good chemical stability
and are available in a variety of useful forms as conformal coat-
ings, encapsulants and adhesives. Dow Corning’s broad range
of general purpose and specialty products offers you a choice of
materials for your application needs.
DESCRIPTION
Dow Corning® silicone encapsulants are supplied as two-part
liquid component kits comprised of:
Mix Ratio Components
(by weight or volume) (as supplied)
1:1 Part A/Part B
10:1 Base/Curing agent
When liquid components are thoroughly mixed, the mixture
cures to a exible elastomer, which is suited for the protection
of electrical/electronic applications. Dow Corning silicone en-
capsulants cure without exotherm at a constant rate regardless
of sectional thickness or degree of connement. Dow Corning
silicone elastomers require no post cure and can be placed
in service immediately following the completion of the cure
schedule with an operating temperature range of -45 to 200°C
(-49 to 392°F). Select materials have been classied by
Underwriters Laboratories and/or meet military specications.
Standard silicone encapsulants require a surface treatment
with a primer in addition to good cleaning for adhesion while
primerless silicone encapsulants require only good cleaning.
Product Description Features Product Potential Uses Application Methods Cure1,2
Silicone Encapsulants Silicone Encapsulants
Sylgard® 160 Silicone
Elastomer
Low cost; good thermal conductivity Two part; 1:1 mix; RT/HA cure; minimal shrinkage; no
exotherm during cure; no solvents or cure byproducts;
repairable; good dielectric properties; deep section cure;
exible elastomer
Sylgard® 160 Silicone
Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
24 hours at 25°C (77°F)
10 minutes at 100°C (212°F)
5 minutes at 150°C (302°F)
Sylgard® 165 Silicone
Elastomer
Fast cure; low cost; good thermal conductivity Sylgard® 165 Silicone
Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing
5 minutes at 25°C (77°F)
Sylgard® 170 Silicone
Elastomer
Low viscosity Sylgard® 170 Silicone
Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
24 hours at 25°C (77°F)
20 minutes at 70°C (158°F)
15 minutes at 85°C (185°F)
10 minutes at 100°C (212°F)
Sylgard® 170 Fast Cure
Silicone Elastomer
Fast cure; low viscosity Sylgard® 170 Fast Cure
Silicone Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing
10 minutes at 25°C (77°F)
Dow Corning® 96-082 A & B
Encapsulant
Very low viscosity; ame retardant; nonmelting; self-
extinguishing; extremely long pot life; wide temperature range
Dow Corning® 96-082
A & B Encapsulant
Applications requiring the thorough
impregnation possible only with a very low
viscosity resin
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
30 minutes at 150°C (302°F)
Sylgard® 182 Silicone
Elastomer
Transparent; long pot life; heat cure Two part; 10:1 mix; minimal shrinkage; no exotherm during
cure; no solvents or cure byproducts; deep section cure;
repairable; good dielectric properties; exible elastomer
Sylgard® 182 Silicone
Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays; adhesive/encapsulant for solar
cells; adhesive handling beam lead integrated
circuits during processing
Supplied as two-part liquid component kits
comprised of Base/Curing Agent to be mixed
in a 10:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
45 minutes at 100°C (212°F)
20 minutes at 125°C (257°F)
10 minutes at 150°C (302°F)
Sylgard® 184 Silicone
Elastomer
Transparent; RT/HA cure Sylgard® 184 Silicone
Elastomer
~48 hours at room temp
45 minutes at 100°C (212°F)
20 minutes at 125°C (257°F)
10 minutes at 150°C (302°F)
Sylgard® 186 Silicone
Elastomer
Clear; RT/HA cure; high tear strength Sylgard® 186 Silicone
Elastomer
~48 hours at room temp
30 minutes at 100°C (212°F)
15 minutes at 150°C (302°F)
Dow Corning® 3-6121
Encapsulating Elastomer
Low-temperature performance below -65°C (-85°F); clear;
high tear and tensile strength; RT/HA cure; high refractive
index
Dow Corning®
3-6121 Encapsulating
Elastomer
Low-temperature encapsulating applications;
optical applications requiring high refractive
index
~48 hours at room temp
20 minutes at 100°C (212°F)
10 minutes at 150°C (302°F)
Primerless Silicone Encapsulants Primerless Silicone Encapsulants
Dow Corning® 3-8264
Primerless Silicone Adhesive
Excellent unprimed adhesion; heat cure; elastomeric Two part; 1:1 mix; heat cure; minimal shrinkage; no
exotherm during cure; no solvents or cure byproducts;
repairable; good dielectric properties
Dow Corning® 3-8264
Primerless Silicone
Adhesive
Encapsulating applications requiring good
primerless adhesion and lower heat cure
temperatures
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated or
manual mixing and dispensing can be used
150 minutes at 70°C (158°F)
30 minutes at 115°C (239°F)
Dow Corning® 567 Primerless
Silicone Encapsulant
Heat cure; unprimed adhesion; elastomeric Dow Corning® 567
Primerless Silicone
Encapsulant
Low cost primerless adhesion encapsulation
applications
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated or
manual mixing and dispensing can be used
90 minutes at 100°C (212°F)
60 minutes at 125°C (257°F)
15 minutes at 150°C (302°F)
Two-Part Room-Temperature Condensation-Cure Encapsulants Two-Part Room-Temperature Condensation-Cure Encapsulants
Dow Corning® 255 Primerless
Elastomer
Rapid room temperature and deep-section cure; self-priming
adhesion; good room-temperature adhesion to most substrates;
adhesion increases with time
Two part; 10:1 mix; noncorrosive; good dielectric properties;
exible elastomer; non-heat curable; refrigerate curing
agent for maximum shelf life; tin catalyst cannot be
inhibited; reversion possible with heat and pressure in sealed
environments
Dow Corning® 255
Primerless Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays
Supplied as two-part liquid component kits
comprised of Base/Curing Agent to be mixed
in a 10:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
~4 hours at room temp
24 hours for adhesion
1These data were collected on 50-100 gram samples of a lot believed to be typical and should be used as initial estimates of cure times. Times will vary slightly
from batch to batch and can be longer or shorter due to thermal mass of your parts and your heating ramp rate. Pretesting is recommended to conrm adequate
cure for your application.
2For primerless adhesion products, cure time is based on time to reach durometer. Full adhesion may take more time at the cure temperature.
PRODUCT INFORMATION
Product Description Features Product Potential Uses Application Methods Cure1,2
Silicone Encapsulants Silicone Encapsulants
Sylgard® 160 Silicone
Elastomer
Low cost; good thermal conductivity Two part; 1:1 mix; RT/HA cure; minimal shrinkage; no
exotherm during cure; no solvents or cure byproducts;
repairable; good dielectric properties; deep section cure;
exible elastomer
Sylgard® 160 Silicone
Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
24 hours at 25°C (77°F)
10 minutes at 100°C (212°F)
5 minutes at 150°C (302°F)
Sylgard® 165 Silicone
Elastomer
Fast cure; low cost; good thermal conductivity Sylgard® 165 Silicone
Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing
5 minutes at 25°C (77°F)
Sylgard® 170 Silicone
Elastomer
Low viscosity Sylgard® 170 Silicone
Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
24 hours at 25°C (77°F)
20 minutes at 70°C (158°F)
15 minutes at 85°C (185°F)
10 minutes at 100°C (212°F)
Sylgard® 170 Fast Cure
Silicone Elastomer
Fast cure; low viscosity Sylgard® 170 Fast Cure
Silicone Elastomer
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing
10 minutes at 25°C (77°F)
Dow Corning® 96-082 A & B
Encapsulant
Very low viscosity; ame retardant; nonmelting; self-
extinguishing; extremely long pot life; wide temperature range
Dow Corning® 96-082
A & B Encapsulant
Applications requiring the thorough
impregnation possible only with a very low
viscosity resin
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
30 minutes at 150°C (302°F)
Sylgard® 182 Silicone
Elastomer
Transparent; long pot life; heat cure Two part; 10:1 mix; minimal shrinkage; no exotherm during
cure; no solvents or cure byproducts; deep section cure;
repairable; good dielectric properties; exible elastomer
Sylgard® 182 Silicone
Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays; adhesive/encapsulant for solar
cells; adhesive handling beam lead integrated
circuits during processing
Supplied as two-part liquid component kits
comprised of Base/Curing Agent to be mixed
in a 10:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
45 minutes at 100°C (212°F)
20 minutes at 125°C (257°F)
10 minutes at 150°C (302°F)
Sylgard® 184 Silicone
Elastomer
Transparent; RT/HA cure Sylgard® 184 Silicone
Elastomer
~48 hours at room temp
45 minutes at 100°C (212°F)
20 minutes at 125°C (257°F)
10 minutes at 150°C (302°F)
Sylgard® 186 Silicone
Elastomer
Clear; RT/HA cure; high tear strength Sylgard® 186 Silicone
Elastomer
~48 hours at room temp
30 minutes at 100°C (212°F)
15 minutes at 150°C (302°F)
Dow Corning® 3-6121
Encapsulating Elastomer
Low-temperature performance below -65°C (-85°F); clear;
high tear and tensile strength; RT/HA cure; high refractive
index
Dow Corning®
3-6121 Encapsulating
Elastomer
Low-temperature encapsulating applications;
optical applications requiring high refractive
index
~48 hours at room temp
20 minutes at 100°C (212°F)
10 minutes at 150°C (302°F)
Primerless Silicone Encapsulants Primerless Silicone Encapsulants
Dow Corning® 3-8264
Primerless Silicone Adhesive
Excellent unprimed adhesion; heat cure; elastomeric Two part; 1:1 mix; heat cure; minimal shrinkage; no
exotherm during cure; no solvents or cure byproducts;
repairable; good dielectric properties
Dow Corning® 3-8264
Primerless Silicone
Adhesive
Encapsulating applications requiring good
primerless adhesion and lower heat cure
temperatures
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated or
manual mixing and dispensing can be used
150 minutes at 70°C (158°F)
30 minutes at 115°C (239°F)
Dow Corning® 567 Primerless
Silicone Encapsulant
Heat cure; unprimed adhesion; elastomeric Dow Corning® 567
Primerless Silicone
Encapsulant
Low cost primerless adhesion encapsulation
applications
Supplied as two-part liquid component kits
comprised of Part A/Part B to be mixed in a
1:1 ratio by weight or volume; automated or
manual mixing and dispensing can be used
90 minutes at 100°C (212°F)
60 minutes at 125°C (257°F)
15 minutes at 150°C (302°F)
Two-Part Room-Temperature Condensation-Cure Encapsulants Two-Part Room-Temperature Condensation-Cure Encapsulants
Dow Corning® 255 Primerless
Elastomer
Rapid room temperature and deep-section cure; self-priming
adhesion; good room-temperature adhesion to most substrates;
adhesion increases with time
Two part; 10:1 mix; noncorrosive; good dielectric properties;
exible elastomer; non-heat curable; refrigerate curing
agent for maximum shelf life; tin catalyst cannot be
inhibited; reversion possible with heat and pressure in sealed
environments
Dow Corning® 255
Primerless Elastomer
General potting applications: power supplies,
connectors, sensors, industrial controls,
transformers, ampliers, high voltage resistor
packs, relays
Supplied as two-part liquid component kits
comprised of Base/Curing Agent to be mixed
in a 10:1 ratio by weight or volume; automated
mixing and dispensing; manual mixing
~4 hours at room temp
24 hours for adhesion
1These data were collected on 50-100 gram samples of a lot believed to be typical and should be used as initial estimates of cure times. Times will vary slightly
from batch to batch and can be longer or shorter due to thermal mass of your parts and your heating ramp rate. Pretesting is recommended to conrm adequate
cure for your application.
2For primerless adhesion products, cure time is based on time to reach durometer. Full adhesion may take more time at the cure temperature.
Product
Mix Ratio
Color
Viscosity,
centipoise or mPa.s
Durometer, Shore A
Specic Gravity
Working Time at RT
Unprimed
Adhesion,
Lap Shear
Thermal
Conductivity
Linear Coefcient
of Thermal Expansion,
µm/m-°C or ppm
Shelf Life from
Date of Manufacture
at Room Temp, months
Product
UL Listing Military Specication
Dielectric
Strength
Dielectric Constant
at 100 Hz
Dielectric Constant
at 100 kHz
Volume Resistivity,
ohm-cm
Dissipation Factor
at 100 Hz
Dissipation Factor
at 100 kHz
psi
MPa
kgf/cm2
Watt/meter-°K
cal/cm.sec °C
Flammability
Classication
UL Temperature
Index, Electrical/
Mechnical, °C
Specication
Type, Class, Group
volts/mil
kV/mm
Silicone Encapsulants Silicone Encapsulants
Sylgard® 160 Silicone
Elastomer 1:1 Gray 4000 60 1.57 30 min NA NA NA 0.58 1.4 x
10-3 240 18 Sylgard® 160 Silicone
Elastomer 94 V-0 105/105 NA NA 530 20.9 3.30 3.20 1.0 x 1015 0.01 0.002
Sylgard® 165 Silicone
Elastomer 1:1 Gray 5000 52 1.57 <2 min NA NA NA 0.58 1.4 x
10-3 230 18 Sylgard® 165 Silicone
Elastomer 94 V-0 105/105 NA NA 530 20.9 3.30 3.20 1.0 x 1015 0.01 0.002
Sylgard® 170 Silicone
Elastomer 1:1
Dark
gray to
black
2900 40 1.37 15 min NA NA NA 0.40 9.6 x
10-4 270 24 Sylgard® 170 Silicone
Elastomer 94 V-0 170/170
MIL-PRF-
23586F
(Grade B2)
Type I,
Class II,
QPL
480 18.9 3.17 3.16 3.1 x 1013 0.003 <0.001
Sylgard® 170 Fast Cure
Silicone Elastomer 1:1
Dark
gray to
black
2850 42 1.37 <5 min NA NA NA 0.40 9.6 x
10-4 –18 Sylgard® 170 Fast Cure
Silicone Elastomer 94 V-0 170/170 NA NA 530 20.9 2.97 2.90 1.4 x 1015 0.005 <0.001
Dow Corning® 96-082
A & B Encapsulant 1:1 Black 1100 31 1.21 14 days NA NA NA 0.30 7.2 x
10-4 285 12 Dow Corning® 96-082
A & B Encapsulant 94 V-0 170/170 NA NA 500 19.7 3.14 3.12 9.5 x 1014 0.0055 <0.001
Sylgard® 182 Silicone
Elastomer 10:1 Clear 3900 50 1.03 >8
hours NA NA NA 0.18 4.3 x
10-4 310 24 Sylgard® 182 Silicone
Elastomer 94 V-1 130/130 MIL-I-
81550C
Type II,
QPL 540 21.2 2.65 2.65 1.2 x 1014 0.0005 <0.001
Sylgard® 184 Silicone
Elastomer 10:1 Clear 3900 50 1.03 >2
hours NA NA NA 0.18 4.3 x
10-4 310 24 Sylgard® 184 Silicone
Elastomer 94 V-1 130/130 MIL-I-
81550C Type I, QPL 540 21.2 2.65 2.65 1.2 x 1014 0.0005 <0.001
Sylgard® 186 Silicone
Elastomer 10:1 Trans-
lucent 65,000 24 1.12 2 hours NA NA NA 0.2 4.8 x
10-4 330 12 Sylgard® 186 Silicone
Elastomer 94 HB 140/140 NA NA 450 17.7 2.93 2.87 1.1 x 1014 0.0012 <0.001
Dow Corning® 3-6121
Encapsulating Elastomer 10:1 Trans-
lucent 25,000 30 1.13 2 hours NA NA NA 0.18 4.3 x
10-4 290 18 Dow Corning® 3-6121
Encapsulating Elastomer NA NA NA NA 415 16.3 2.92 2.92 1.4 x 1014 0.01 <0.001
Primerless Silicone Encapsulants Primerless Silicone Encapsulants
Dow Corning® 3-8264
Primerless Silicone
Adhesive
1:1 Black 2900 45 1.32 5 hours 385 2.6 27.0 0.35 8.4 x
10-4 290 9
Dow Corning® 3-8264
Primerless Silicone
Adhesive
NA NA NA NA 545 21.4 3.11 3.05 3.5 x 1014 0.007 <0.001
Dow Corning® 567
Primerless Silicone
Encapsulant
1:1 Black 1500 45 1.24 >3 days 140 1.0 9.8 0.30 7.2 x
10-4 300 24
Dow Corning® 567
Primerless Silicone
Encapsulant
94 V-0 105/105
MIL-PRF-
23586F
(Grade B2)
Type I,
Class IV,
QPL
520 20.5 2.85 2.79 1.0 x 1014 0.008 0.002
Two-Part Room-Temperature Condensation-Cure Encapsulants Two-Part Room-Temperature Condensation-Cure Encapsulants
Dow Corning® 255
Primerless Elastomer 10:1 Gray to
black 5500 25 1.3 <5 min 44 0.3 20 0.26 6.25 x
10-6 311 Dow Corning® 255
Primerless Elastomer 564 25 2.95 2.83 1.1 x 1015 0.017 <0.0059
TYPICAL PROPERTIES
Specication Writers: Please contact your local Dow Corning sales ofce or your Global Dow Corning Connection before writing specications on this product.
Product
Mix Ratio
Color
Viscosity,
centipoise or mPa.s
Durometer, Shore A
Specic Gravity
Working Time at RT
Unprimed
Adhesion,
Lap Shear
Thermal
Conductivity
Linear Coefcient
of Thermal Expansion,
µm/m-°C or ppm
Shelf Life from
Date of Manufacture
at Room Temp, months
Product
UL Listing Military Specication
Dielectric
Strength
Dielectric Constant
at 100 Hz
Dielectric Constant
at 100 kHz
Volume Resistivity,
ohm-cm
Dissipation Factor
at 100 Hz
Dissipation Factor
at 100 kHz
psi
MPa
kgf/cm2
Watt/meter-°K
cal/cm.sec °C
Flammability
Classication
UL Temperature
Index, Electrical/
Mechnical, °C
Specication
Type, Class, Group
volts/mil
kV/mm
Silicone Encapsulants Silicone Encapsulants
Sylgard® 160 Silicone
Elastomer 1:1 Gray 4000 60 1.57 30 min NA NA NA 0.58 1.4 x
10-3 240 18 Sylgard® 160 Silicone
Elastomer 94 V-0 105/105 NA NA 530 20.9 3.30 3.20 1.0 x 1015 0.01 0.002
Sylgard® 165 Silicone
Elastomer 1:1 Gray 5000 52 1.57 <2 min NA NA NA 0.58 1.4 x
10-3 230 18 Sylgard® 165 Silicone
Elastomer 94 V-0 105/105 NA NA 530 20.9 3.30 3.20 1.0 x 1015 0.01 0.002
Sylgard® 170 Silicone
Elastomer 1:1
Dark
gray to
black
2900 40 1.37 15 min NA NA NA 0.40 9.6 x
10-4 270 24 Sylgard® 170 Silicone
Elastomer 94 V-0 170/170
MIL-PRF-
23586F
(Grade B2)
Type I,
Class II,
QPL
480 18.9 3.17 3.16 3.1 x 1013 0.003 <0.001
Sylgard® 170 Fast Cure
Silicone Elastomer 1:1
Dark
gray to
black
2850 42 1.37 <5 min NA NA NA 0.40 9.6 x
10-4 –18 Sylgard® 170 Fast Cure
Silicone Elastomer 94 V-0 170/170 NA NA 530 20.9 2.97 2.90 1.4 x 1015 0.005 <0.001
Dow Corning® 96-082
A & B Encapsulant 1:1 Black 1100 31 1.21 14 days NA NA NA 0.30 7.2 x
10-4 285 12 Dow Corning® 96-082
A & B Encapsulant 94 V-0 170/170 NA NA 500 19.7 3.14 3.12 9.5 x 1014 0.0055 <0.001
Sylgard® 182 Silicone
Elastomer 10:1 Clear 3900 50 1.03 >8
hours NA NA NA 0.18 4.3 x
10-4 310 24 Sylgard® 182 Silicone
Elastomer 94 V-1 130/130 MIL-I-
81550C
Type II,
QPL 540 21.2 2.65 2.65 1.2 x 1014 0.0005 <0.001
Sylgard® 184 Silicone
Elastomer 10:1 Clear 3900 50 1.03 >2
hours NA NA NA 0.18 4.3 x
10-4 310 24 Sylgard® 184 Silicone
Elastomer 94 V-1 130/130 MIL-I-
81550C Type I, QPL 540 21.2 2.65 2.65 1.2 x 1014 0.0005 <0.001
Sylgard® 186 Silicone
Elastomer 10:1 Trans-
lucent 65,000 24 1.12 2 hours NA NA NA 0.2 4.8 x
10-4 330 12 Sylgard® 186 Silicone
Elastomer 94 HB 140/140 NA NA 450 17.7 2.93 2.87 1.1 x 1014 0.0012 <0.001
Dow Corning® 3-6121
Encapsulating Elastomer 10:1 Trans-
lucent 25,000 30 1.13 2 hours NA NA NA 0.18 4.3 x
10-4 290 18 Dow Corning® 3-6121
Encapsulating Elastomer NA NA NA NA 415 16.3 2.92 2.92 1.4 x 1014 0.01 <0.001
Primerless Silicone Encapsulants Primerless Silicone Encapsulants
Dow Corning® 3-8264
Primerless Silicone
Adhesive
1:1 Black 2900 45 1.32 5 hours 385 2.6 27.0 0.35 8.4 x
10-4 290 9
Dow Corning® 3-8264
Primerless Silicone
Adhesive
NA NA NA NA 545 21.4 3.11 3.05 3.5 x 1014 0.007 <0.001
Dow Corning® 567
Primerless Silicone
Encapsulant
1:1 Black 1500 45 1.24 >3 days 140 1.0 9.8 0.30 7.2 x
10-4 300 24
Dow Corning® 567
Primerless Silicone
Encapsulant
94 V-0 105/105
MIL-PRF-
23586F
(Grade B2)
Type I,
Class IV,
QPL
520 20.5 2.85 2.79 1.0 x 1014 0.008 0.002
Two-Part Room-Temperature Condensation-Cure Encapsulants Two-Part Room-Temperature Condensation-Cure Encapsulants
Dow Corning® 255
Primerless Elastomer 10:1 Gray to
black 5500 25 1.3 <5 min 44 0.3 20 0.26 6.25 x
10-6 311 Dow Corning® 255
Primerless Elastomer 564 25 2.95 2.83 1.1 x 1015 0.017 <0.0059
MIXING – 1:1/PART A:PART B
Dow Corning silicone 1:1 encapsulants are supplied in two
parts that do not require lot matching. The 1:1 mix ratio, by
weight or volume, simplies the proportioning process. To
ensure uniform distribution of ller, Parts A and B must each
be thoroughly mixed prior to their combination in a 1:1 ratio.
When thoroughly blended, the Part A and B liquid mixture
should have a uniform appearance. The presence of light-
colored streaks or marbling indicates inadequate mixing and
will result in incomplete cure.
Due to the fast-curing characteristics of some encapsulants
included in this data sheet, automated mix and dispense equip-
ment should be utilized. In applications sensitive to air entrap-
ment, deairing with 28 to 30 inches Hg vacuum is required.
MIXING – 10:1/BASE:CURING AGENT
Dow Corning silicone 10:1 encapsulants are supplied in two
parts as lot-matched base and curing agent that are mixed in
a ratio of 10 parts base to one part curing agent, by weight.
After thoroughly mixing base and curing agent, agitate gently
to reduce the amount of air introduced. Allowing the mixture
to set for 30 minutes before pouring may be adequate for
removal of the air introduced during mixing. If air bubbles
are still present, vacuum deairing may be required. Deair in a
container with at least four times the liquid volume to allow
for expansion of material. Air entrapped in the mixture can be
removed by using a vacuum of 28 to 30 inches Hg. Continue
the vacuum until the liquid expands and settles to its original
volume and bubbling subsides. This may take 15 minutes to
2 hours depending on the amount of air introduced during
stirring. For best curing results, glassware and glass or metal
stirring implements should be used. Mix with a smooth action
that does not introduce excess air.
POT LIFE/WORKING TIME
Cure reaction begins with the mixing process. Initially, cure
is evidenced by a gradual increase in viscosity, followed by
gelation and conversion to a solid elastomer. Pot life is dened
as the time required for viscosity to double after Parts A and B
(base and curing agent) are mixed. Please refer to individual
pot life for each silicone encapsulant.
PROCESSING AND CURING
Thoroughly mixed Dow Corning silicone encapsulant may be
poured/dispensed directly into the container in which it is to be
cured. Care should be taken to minimize air entrapment. When
practical, pouring/dispensing should be done under vacuum,
particularly if the component being potted or encapsulated has
many small voids. If this technique cannot be used, the unit
should be evacuated after the silicone encapsulant has been
poured/dispensed.
Dow Corning silicone encapsulants may be either room tem-
perature (25°C/77°F) or heat cured. Room temperature cure
encapsulants may also be heat accelerated for faster cure. Ideal
PRIMER SELECTION GUIDE
Specication Writers: Please contact your local Dow Corning sales ofce or your Global Dow Corning Connection before writing
specications on these products.
Dow Corning® brand
Primer or Adhesion
Promoter
Flash
Point, °C
(°F)
Volatile
Organic
Content
(VOC)4,
grams/liter
Special
Properties For Use On For Use With
P5200 Clear131 (87) 77/522 Most metals, glass,
ceramics and some
plastics
Pigmented two-part addition
cure
1200 Clear 13 (55) 723
1200 Red 13 (55) 723 Colored for easier
identication
P5200 Red231 (87) 77/521
1204 8 (46) 753 Most metals, glass and
ceramics
All one-part alcohol cure
P5204314 (57) 205/591
1205 13 (55) 862 Film-forming Most plastics All
3-6060 15 (59) 784 Improves inhibition
resistance
Most plastics and metals All two-part addition cure
92-023 -13 (9) 681 Most metals, glass and
ceramics
Sylgard® Prime Coat -13 (9) 688
1P5200 Clear is a low-VOC alternative to 1200 Clear.
2P5200 Red is a low-VOC alternative to 1200 Red.
3P5204 is a low-VOC alternative to 1204.
4The lower VOC value is for states and air quality management districts that have recognized volatile methylsiloxanes as VOC exempt.
cure conditions for each product are given in the product se-
lection table. Two-part condensation cure encapsulants should
not be heat accelerated above 60°C (140°F).
Dow Corning® 255 Curing Agent should be stirred prior to use
because some settling may occur during shipping and storage.
The curing agent is reactive with atmospheric moisture so care
should be exercised to limit exposure to air prior to use.
PREPARING SURFACES
In applications requiring adhesion, priming will be required
for the silicone encapsulants. See the Primer Selection Guide
for the correct primer to use with a given product. For best
results, the primer should be applied in a very thin, uniform
coating and then wiped off after application. After application,
it should be thoroughly air dried prior to application of the
silicone elastomer. Additional instructions for primer usage
can be found in the Dow Corning literature, “How To Use
Dow Corning Primers and Adhesion Promoters” (Form No.
10-366) and in the information sheets specic to the individual
primers.
USEFUL TEMPERATURE RANGES
For most uses, silicone elastomers should be operational over
a temperature range of -45 to 200°C (-49 to 392°F) for long
periods of time. However, at both the low and high tempera-
ture ends of the spectrum, behavior of the materials and per-
formance in particular applications can become more complex
and require additional considerations.
For low-temperature performance, thermal cycling to condi-
tions such as -55°C (-67°F) may be possible, but performance
should be veried for your parts or assemblies. Factors that
may inuence performance are conguration and stress sensi-
tivity of components, cooling rates and hold times, and prior
temperature history. There are specialized products including
Dow Corning® 3-6121 Encapsulating Elastomer that can per-
form at -65°C (-85°F) and below.
At the high-temperature end, the durability of the cured
silicone elastomer is time and temperature dependent. As
expected, the higher the temperature, the shorter the time the
material will remain usable.
COMPATIBILITY
Certain materials, chemicals, curing agents and plasticizers
can inhibit the cure of Dow Corning silicone encapsulants.
Most notable of these include:
• Organotin and other organometallic compounds
• Silicone rubber containing organotin catalyst
• Sulfur, polysuldes, polysulfones or other sulfur-containing
materials
• Amines, urethanes or amine-containing materials
• Unsaturated hydrocarbon plasticizers
• Some solder ux residues
If a substrate or material is questionable with respect to po-
tentially causing inhibition of cure, it is recommended that a
small scale compatibility test be run to ascertain suitability in a
given application. The presence of liquid or uncured product at
the interface between the questionable substrate and the cured
gel indicates incompatibility and inhibition of cure.
Dow Corning 255 Elastomer is not subject to these inhibition
concerns but may experience reversion in sealed applications
at high temperature and pressure.
REPAIRABILITY
In the manufacture of electrical/electronic devices it is often
desirable to salvage or reclaim damaged or defective units.
With most non-silicone rigid potting/encapsulating materials,
removal or entry is difcult or impossible without causing
excessive damage to internal circuitry. Dow Corning silicone
encapsulants can be selectively removed with relative ease,
any repairs or changes accomplished, and the repaired area
repotted in place with additional product.
To remove silicone elastomers, simply cut with a sharp blade
or knife and tear and remove unwanted material from the
area to be repaired. Sections of the adhered elastomer are best
removed from substrates and circuitry by mechanical action
such as scraping or rubbing and can be assisted by applying
Dow Corning® brand OS Fluids.
Before applying additional encapsulant to a repaired device,
roughen the exposed surfaces of the cured encapsulant with an
abrasive paper and rinse with a suitable solvent. This will
enhance adhesion and permit the repaired material to become
an integral matrix with the existing encapsulant. Silicone
prime coats are not recommended for adhering products to
themselves.
HANDLING PRECAUTIONS
Dow Corning 255 Elastomer curing agent and uncured cata-
lyzed material will burn skin and eyes upon prolonged contact.
In case of eye contact, ush with copious amounts of water
for at least 15 minutes and seek medical attention at once.
Skin contact areas should be washed with soap and water.
Persistent irritation should receive medical attention. Use
only with adequate ventilation; if not available, use respiratory
protection.
PRODUCT SAFETY INFORMATION REQUIRED FOR
SAFE USE IS NOT INCLUDED IN THIS DOCUMENT.
BEFORE HANDLING, READ PRODUCT AND MATERIAL
SAFETY DATA SHEETS AND CONTAINER LABELS
FOR SAFE USE, PHYSICAL AND HEALTH HAZARD
INFORMATION. THE MATERIAL SAFETY DATA SHEET
IS AVAILABLE ON THE DOW CORNING WEBSITE
AT WWW.DOWCORNING.COM, OR FROM YOUR
DOW CORNING REPRESENTATIVE, OR DISTRIBUTOR,
OR BY CALLING YOUR GLOBAL DOW CORNING
CONNECTION.
Dow Corning and Sylgard are registered trademarks of Dow Corning Corporation.
©2000, 2001, 2003, 2005 Dow Corning Corporation. All rights reserved.
Printed in USA AGP7297 Form No. 10-898E-01
USABLE LIFE AND STORAGE
Shelf life is indicated by the “Use By” date found on the
product label.
For best results, Dow Corning silicone encapsulants should
be stored at or below 25°C (77°F). Special precautions must
be taken to prevent moisture from contacting these materials.
Containers should be kept tightly closed and head or air space
minimized. Partially lled containers should be purged with
dry air or other gases, such as nitrogen.
Dow Corning 255 Elastomer should be kept refrigerated
(10°C/50°F) until use. Any special storage and handling in-
structions will be printed on the product containers.
PACKAGING
In general, Dow Corning silicone 1:1 mix ratio encapsulants
are supplied in nominal 0.45-, 3.6-, 18- and 200-kg (1-, 8-,
40- and 440-lb) containers, net weight. Dow Corning silicone
10:1 mix ratio encapsulants are supplied in nominal 0.5-,
5-, 25- and 225-kg (1.1-, 11-, 55- and 495-lb) containers,
net weight. Packaging options may vary by product.
Consult Dow Corning Customer Service at (989) 496-6000
for additional packaging options.
LIMITATIONS
These products are neither tested nor represented as suitable
for medical or pharmaceutical uses.
HEALTH AND ENVIRONMENTAL
INFORMATION
To support customers in their product safety needs,
Dow Corning has an extensive Product Stewardship
organization and a team of Product Safety and Regulatory
Compliance (PS&RC) specialists available in each area.
For further information, please see our website,
www.dowcorning.com, or consult your local
Dow Corning representative.
LIMITED WARRANTY INFORMATION –
PLEASE READ CAREFULLY
The information contained herein is offered in good faith and
is believed to be accurate. However, because conditions and
methods of use of our products are beyond our control, this
information should not be used in substitution for customer’s
tests to ensure that Dow Corning’s products are safe, effective,
and fully satisfactory for the intended end use. Suggestions of
use shall not be taken as inducements to infringe any patent.
Dow Corning’s sole warranty is that the product will meet
the Dow Corning sales specications in effect at the time of
shipment.
Your exclusive remedy for breach of such warranty is limited
to refund of purchase price or replacement of any product
shown to be other than as warranted.
DOW CORNING SPECIFICALLY DISCLAIMS
ANY OTHER EXPRESS OR IMPLIED WARRANTY
OF FITNESS FOR A PARTICULAR PURPOSE OR
MERCHANTABILITY.
DOW CORNING DISCLAIMS LIABILITY FOR ANY
INCIDENTAL OR CONSEQUENTIAL DAMAGES.
