Scotch-Weld
Epoxy Adhesive
Technical Data
TM
DP420 Black
•
DP420 NS Black
•
DP420 Off-White
•
DP420 LH
July, 2018
Product Description
3M™ Scotch-Weld™ Epoxy Adhesives are high performance, two-part epoxy
adhesives offering outstanding shear and peel adhesion, and very high levels of
durability.
Features
• High shear strength
• High peel strength
• Outstanding environmental
performance
• Easy mixing
• 20 minute worklife
• Controlled flow (3M™ Scotch-Weld™ Epoxy
Adhesive DP420 NS Black)
• Recognized as meeting UL 94 HB – Underwriters
Laboratory Horizontal Burn Flammability Test
(3M™ Scotch-Weld™ Epoxy Adhesive DP420
Off-White)
• Low halogen content (3M™ Scotch-Weld™
Epoxy Adhesive DP420 LH)
Typical Uncured
Physical Properties
Note: The following technical information and data should be considered representative
or typical only and should not be used for specification purposes.
3M™ Scotch-Weld™ Epoxy Adhesive
Product
Viscosity (approx.)
@ 73°F (23°C)
Base Resin
Color
Net Weight
Lbs./Gallon
Mix Ratio (B:A)
Base
Accelerator
Base
Accelerator
Base
Accelerator
Base
Accelerator
Volume
Weight
DP420 Black
20,000-50,000 cP
8,000-14,000 cP
epoxy
amine
black
amber
9.3-9.7
9.0-9.4
2:1
2:0.97
15 minutes
20 minutes
30 minutes
DP420 NS Black
190,000-270,000 cP
60,000-130,000 cP
epoxy
amine
black
amber
9.4-9.8
9.1-9.5
2:1
2:0.97
15 minutes
20 minutes
30 minutes
DP420 Off-White
20,000-50,000 cP
8,000-14,000 cP
epoxy
amine
white
amber
9.3-9.7
9.0-9.4
2:1
2:0.97
15 minutes
20 minutes
30 minutes
DP420 LH
20,000-50,000 cP
8,000-14,000 cP
epoxy
amine
white
amber
9.3-9.7
9.0-9.4
2:1
2:0.97
15 minutes
20 minutes
30 minutes
Worklife, 73°F (23°C) 20 g mixed
10 g mixed
5 g mixed
-1-
3M
™
Scotch-Weld
™
Epoxy Adhesive
DP420 Black • DP420 NS Black • DP420 Off-White • DP420 LH
Typical Cured
Properties
Note: The following technical information and data should be considered representative
or typical only and should not be used for specification purposes.
The properties of cured 3M™ Scotch-Weld™ Epoxy Adhesive DP420 NS Black
and 3M™ Scotch-Weld™ Epoxy Adhesive DP420 LH are expected to be similar to
the properties of 3M™ Scotch-Weld™ Epoxy Adhesive DP420 Black and 3M™
Scotch-Weld™ Epoxy Adhesive DP420 Off-White, respectively as described by
data in the following sections of this technical data sheet.
An exception to this is the concentration of halogens in 3M™ Scotch-Weld™
Epoxy Adhesive DP420 LH. 3M™ Scotch-Weld™ Epoxy Adhesive DP420 LH is
a form of 3M™ Scotch-Weld™ Epoxy Adhesive DP420 Off-White that can be
considered “low halogen”. Low halogen is defined by the Electrotechnical
Commission (IEC) 61249-2-21 standard as having less than 900 ppm chlorine,
900 ppm bromine, and less than 1500 ppm total chlorine and bromine.
3M™ Scotch-Weld™ Epoxy Adhesive DP420 LH Test Results
Halogens (determined by ion chromatography)
Total Chlorine (ppm)
720
Total Bromine (ppm)
<5
Total Halogens (ppm)
<800
Product
Physical
Color
Shore D Hardness
Thermal
Coefficient of Thermal
Expansion
(in./in./°C)
3M™ Scotch-Weld™
Epoxy Adhesive
DP420 Black
Black
75-80
3M™ Scotch-Weld™
Epoxy Adhesive
DP 420 Off-White
Opaque, off-white
75-80
Below Tg
Above Tg
80 x 10
-6
194 x 10
-6
0.104
85 x 10
-6
147 x 10
-6
0.104
Thermal Conductivity
(btu - ft./ft.
2
- hr. - °F) @ 45°C
Electrical
Dielectric Strength (ASTM D 149)
Volume Resistivity (ASTM D 257)
888 volts/mil
1.6 x 10
15
ohm-cm
690 volts/mil
1.3 x 10
14
ohm-cm
-2-
3M
™
Scotch-Weld
™
Epoxy Adhesive
DP420 Black • DP420 NS Black • DP420 Off-White • DP420 LH
Typical Curing
Characteristics
Note: The following technical information and data should be considered representative
or typical only and should not be used for specification purposes.
Rate of Strength Build-Up
Aluminum, Overlap Shear (7 mil Bondline) (ASTM D 1002-72)
Bonds Tested at 73°F (23°C)
3M™ Scotch-Weld™ Epoxy Adhesive DP420 Black
Time in Oven
73°F (23°C)
15 min.
30
60
2 hr.
3
5
6
24
1
This
Cure Temperature
120°F
1
(49°C)
NT
2300
4700
140°F
1
(60°C)
3200
NT
4700
NT
NT
NT
300
800
3000
3700
4500
represents the oven temperature to which the bonds were subjected for the prescribed
time. The average bondline temperature during the cure time will be somewhat lower than
the oven temperature.
NOTE:
The data in this data sheet were generated using the 3M™ EPX Applicator System
equipped with an EPX static mixer, according to manufacturer’s directions. Thorough
hand-mixing will afford comparable results.
-3-
3M
™
Scotch-Weld
™
Epoxy Adhesive
DP420 Black • DP420 NS Black • DP420 Off-White • DP420 LH
Typical Adhesive
Performance
Characteristics
Note: The following technical information and data should be considered representative or
typical only and should not be used for specification purposes.
Substrates and Testing
A. Overlap Shear (ASTM D 1002-72)
Overlap shear (OLS) strengths were measured on 1 in. wide 1/2 in. overlap specimens. These
bonds were made individually using 1 in. x 4 in. pieces of substrate except for aluminum. Two
panels 0.063 in. thick, 4 in. x 7 in. of 2024T-3 clad aluminum were bonded and cut into 1 in.
wide samples after 24 hours. The thickness of the bondline was 0.005-0.008 in. All strengths
were measured at 73°F (23°C) except where noted.
The separation rate of the testing jaws was 0.1 in. per minute for metals, 2 in. per minute for
plastics and 20 in. per minute for rubbers. The thickness of the substrates were: steel, 0.060 in.;
other metals, 0.05-0.064 in.; rubbers, 0.125 in.; plastics, 0.125 in.
B. T-peel (ASTM D 1876-61T)
T-peel strengths were measured on 1 in. wide bonds at 73°F (23°C). The testing jaw separation
rate was 20 inches per minute. The substrates were 0.032 in. thick.
C. Bell Peel (ASTM D 3167)
Bell peel strengths were measured on 1/2 in. wide bonds at the temperatures noted. The testing
jaw separation rate was 6 in. per minute. The bonds are made with 0.064 in. bonded to 0.025 in.
thick adherends.
D. Cure Cycle
With the exception of Rate of Strength Build-Up Tests, all bonds, were cured 7 days at 73°F
(23°C) at 50% RH before testing or subjected to further conditioning or environmental aging.
3M™ Scotch-Weld™
3M™ Scotch-Weld™
Epoxy Adhesive DP420 Epoxy Adhesive DP420
Black
Off-White
-67°F (-55°C)
73°F (23°C)
180°F (82°C) (15 min.)
1
(30 min.)
1
(60 min.)
1
(4 hr.)
1
250°F (121°C) (15 min.)
1
4500
4500
1260
2250
2980
2690
570
4500
4500
450
700
750
2500
200
3M™ Scotch-Weld™
Epoxy Adhesive
DP420NS Black
4500
4500
4500
860
1400
1600
21
2100
350
Aluminum, Overlap Shear, at Temperature (PSI)
1
Represents time in test chamber oven before test.
Metals, Overlap Shear, Tested @ 73°F (23°C) (PSI)
3M™ Scotch-
Weld™ Epoxy
Adhesive DP420
Black
Aluminum-
Etched
Oakite degrease
MEK/abrade/MEK
4500
4000
2500
—
2200
5000
2800
1800
2900
3000
3M™ Scotch-
3M™ Scotch-
Weld™ Epoxy
weld™ Epoxy
Adhesive DP420 Adhesive DP420NS
Off-White
Black
4500
3500
3500
4000
2700
4000
4100
1700
2000
2100
4500
NT
3500
NT
2500
3000
3500
3900
NT
NT
Cold Rolled Steel- Oakite degrease
MEK/abrade/MEK
Copper-
Brass-
Stainless Steel-
MEK/abrade/MEK
MEK/abrade/MEK
MEK/abrade/MEK
Galvanized Steel- Hot dipped
Electrodeposited
-4-
3M
™
Scotch-Weld
™
Epoxy Adhesive
DP420 Black • DP420 NS Black • DP420 Off-White • DP420 LH
NT: Not tested
Typical Adhesive
Performance
Characteristics
(continued)
Note: The following technical information and data should be considered representative
or typical only and should not be used for specification purposes.
Substrates and Testing
(continued)
Aluminum, T-Peel (PIW), at Temperature
3M™ Scotch-Weld™ 3M™ Scotch-Weld™
Epoxy Adhesive
Epoxy Adhesive
DP420 Black
DP420 Off-White
-67°F (-55°C)
73°F (23°C)
180°F (82°C)
9.3
50
20
5-10
50
3-5
Metals, T-Peel, Tested @ 73°F (23°C) (PIW)
3M™ Scotch-
Weld™ Epoxy
Adhesive DP420
Black
60
50
40
25
3M™Scotch-
Weld™ Epoxy
Adhesive DP420
Off-White
50
40
40
25
Aluminum, etched
Cold Rolled Steel
17-20 mil bondline
5-8 mil bondline
17-20 mil bondline
Oakite degreased
MEK/abrade/MEK
Aluminum, Bell Peel (PIW), at Temperature
3M™ Scotch-Weld™
3M™ Scotch-Weld™
Epoxy Adhesive
Epoxy Adhesive DP420
DP420 Black
Off-White
-67°F (-55°C)
73°F (23°C)
180°F (82°C)
20
82
18
not tested
3M™ Scotch-Weld™
Epoxy Adhesive
DP420NS Black
Not tested
58
Not tested
Other Substrates, Overlap Shear Tested @ 73°F (23°C) (PSI)
Substrate
ABS
PVC
Polycarbonate
Polyacrylic
Polystryene
FRP
Phenolic
SBR/Steel
Neoprene/Steel
Surf. Prep. 11
Surf. Prep. 22
3M Scotch-Weld 3M Scotch-Weld 3M Scotch-Weld 3M Scotch-Weld 3M Scotch-Weld
Epoxy Adhesive Epoxy Adhesive Epoxy Adhesive Epoxy Adhesive Epoxy Adhesive
DP420 Black DP420 Off-White DP420 Black
DP420 Off White DP420NS Black
450
4003
440
190
380
600
14003
70
80
320
220
400
230
350
350
14003
1503
40
550
3603
450
450
580
11003
13003
1803
100
500
300
550
280
380
13003
14003
1503
80
870
NT
470
NT
NT
3700
1170
NT
NT
1Isopropyl Alcohol Wipe. See Surface Preparation Section D for additional information.
2Isopropyl Alcohol/Abrade/Isopropyl Alcohol: See Surface Preparation Section E for additional information.
3Substrate failure.
-5-