LOCTITE 420
Harmonization Code : 3907.30.00.40 | Epoxy Mold Compounds containing by weight more than 70 % silicon dioxide
Main features
- Very-Low-Viscosity Capillary Bonding
- Fast Close-Fitting Assembly
- Broad Metal-Plastic-Rubber Bonding
Product Description
LOCTITE 420 is a one-component, very-low-viscosity ethyl cyanoacrylate instant adhesive for general-purpose bonding of plastics, rubbers, and metals. The transparent, colorless-to-straw liquid requires no mixing and cures with atmospheric moisture. At 22 deg C and 50% relative humidity, fixture times range from under 5 seconds on neoprene and nitrile rubber to 5 to 15 seconds on aluminum and 10 to 30 seconds on degreased mild steel. After 24 hours at 22 deg C, grit-blasted steel lap shear strength is 15 to 26 N/mm^2. The material is intended for thin, close-fitting bond gaps.
Key features
- Very-Low-Viscosity Flow: A 1 to 5 mPa s viscosity supports capillary flow into thin, close-fitting joints.
- Fast Close-Fitting Assembly: Neoprene and nitrile fixture in under 5 seconds under the listed ambient condition.
- Broad Substrate Bonding: The adhesive bonds plastics, rubbers, and metals with substrate-specific strength data.
Applications / Suitable for
- General-purpose plastic bonding
- Rubber and elastomer bonding
- Thin, close-fitting metal joints
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Chemistry Type
Ethyl cyanoacrylate
Color
Transparent, colorless to straw colored liquid
The color
Component System
One component
Describes the number of components that must be supplied, mixed, or activated before application or cure.
Specific Gravity
1.05
Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume.
For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.
Thermal Properties
Linear thermal expansion
100×10^-6 K -1
Thermal Conductivity
0.1 W/m.K
Thermal conductivity describes the ability of a material to conduct heat. It is required by power packages in order to dissipate heat and maintain stable electrical performance.
Thermal conductivity units are [W/(m K)] in the SI system and [Btu/(hr ft °F)] in the Imperial system.
Physical Properties
Viscosity
1 to 5 mPa.s
Viscosity is a measurement of a fluid’s resistance to flow.
Viscosity is commonly measured in centiPoise (cP). One cP is defined as
the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP.
A product like honey would have a much higher viscosity -around 10,000 cPs-
compared to water. As a result, honey would flow much slower out of a tipped glass than
water would.
The viscosity of a material can be decreased with an increase in temperature in
order to better suit an application
Electrical Properties
Dielectric Strength
25 kV/mm
Dielectric strength is measured in kV per mm and is calculated by the Breakdown voltage divided by the thickness of the tested material.
Those two properties go hand in hand and while Breakdown voltage is always thickness dependent, dielectric strength is a general material property.
As an example, the dielectric strength of Polyimide is 236 kV/mm. If we place 1mm of Polyimide between two electrodes, it will act as an insulator until the voltage between the electrodes reaches 236 kV. At this point it will start acting as a good conductor, causing sparks, potential punctures and current flow.
Volume Resistivity
2×10^15 Ohms⋅cm
Volume resistivity, also called volume resistance, bulk resistance or bulk resistivity is a thickness dependent measurement of the resistivity of a material perpendicular to the plane of the surface.
Curing Conditions
Fixture Time
10 to 30 seconds
Additional Information
Technical properties
As-supplied / before-processing properties
Typical values for the uncured or as-supplied product unless otherwise noted.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Transparent, colorless to straw | - | Uncured |
| Specific gravity | 1.05 | - | 25 deg C |
| Viscosity | 1 to 4 | mPa s | Cone and plate, shear rate 3,000 s^-1, 25 deg C |
| Viscosity | 1 to 5 | mPa s | Brookfield LVF, spindle 1, 6 rpm, 25 deg C |
| Vapor pressure | <1 | hPa | As supplied |
Technical properties
After-processing / final-state properties
Typical values for the cured product under the listed methods and conditions.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Coefficient of thermal expansion | 100 x 10^-6 | K^-1 | ISO 11359-2; cured 24 hours at 22 deg C |
| Thermal conductivity | 0.1 | W/(m K) | ISO 8302; same cure |
| Softening point | 165 | deg C | DIN EN 1427; cured material |
| Dielectric breakdown strength | 25 | kV/mm | IEC 60243-1; cured material |
| Lap shear strength | 15 to 26 | N/mm^2 | Grit-blasted steel; cured 24 hours at 22 deg C |
| Lap shear strength | 12 to 19 | N/mm^2 | Grit-blasted aluminum; cured 24 hours at 22 deg C |
| Tensile strength | 12 to 25 | N/mm^2 | ISO 6922; steel; cured 24 hours at 22 deg C |
