LOCTITE SI 5091
Harmonization Code : 3907.30.00.40 | Epoxy Mold Compounds containing by weight more than 70 % silicon dioxide
Main features
- Self-Leveling Cavity Filling
- UV and Moisture Cure Access
- Flexible Shock-Absorbing Seal
Product Description
LOCTITE SI 5091 is a one-component, self-leveling acetoxy silicone for potting, coating and sealing. UV light provides the primary cure, while atmospheric moisture cures shadowed areas. At 25 deg C, typical viscosity is 4,000 to 6,000 mPa s, and additional cure properties develop over 72 hours at ambient conditions. Cured properties include Shore A hardness of 31 to 37, elongation of at least 75% and dielectric breakdown strength of 18 kV/mm in a highly flexible elastomer. Applications include automotive, electronic, military and industrial components.
Key features
- Self-leveling fill: The liquid is self-leveling for uniform cavity fill.
- UV-plus-moisture cure: UV light provides primary cure while moisture cures shadowed areas.
- Flexible cured elastomer: Cured material has Shore A hardness of 31 to 37 and elongation of at least 75%.
Applications
Potting, coating and sealing automotive, electronic, military and industrial components.
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Appearance
Translucent liquid
Appearance at room temperature.
Chemistry Type
Acetoxy silicone
Solids
>95 %
Specific Gravity
1.01
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.
Physical Properties
Tack-Free Time
≤0.33 minutes
Viscosity
4,000 to 6,000 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
Chemical Properties
Water Absorption
0 %
Mechanical Properties
Elongation
≥75 %
Elongation is the process of lengthening something.
It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks.
It is commonly referred to as Ultimate Elongation or Tensile Elongation at break.
Electrical Properties
Volume Resistivity
3.3×10 ¹³ 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.
Additional Information
Technical properties
As-supplied / before-processing properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Appearance | Translucent liquid | Uncured; LMS | |
| Specific gravity | 1.01 | Typical; 25 deg C | |
| Solids/non-volatile content | >95 | % | Typical; uncured |
| Viscosity | 4,000 to 6,000 | mPa s | LMS; Brookfield RVT; spindle 3; 10 rpm; 25 deg C |
Technical properties
After-processing / final-state properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Shore hardness | 31 to 37 | Shore A | LMS; ISO 868; 75 mW/cm^2 at 365 nm for 60 s/side, then 3 days at 22 deg C/50 +/- 5% RH |
| Elongation | >=75 | % | LMS; ISO 37; stated light cure plus 3 days at 22 deg C/50 +/- 5% RH |
| Tensile strength | >=0.6 | N/mm^2 | LMS; ISO 37; stated light cure plus 3 days at 22 deg C/50 +/- 5% RH |
| Shrinkage | 0.2 | % | Typical; 40 mW/cm^2 for 60 s/side, then 7 days at 22 deg C/50% RH |
| Tear strength | 0.7 | N/mm | Typical; ISO 34-1, Die B; stated light cure plus 7 days at 22 deg C/50% RH |
| Dielectric breakdown strength | 18 | kV/mm | Typical; IEC 60243-1; stated light cure plus 7 days at 22 deg C/50% RH |
| Volume resistivity | 3.3 x 10^13 | ohm cm | Typical; IEC 60093; stated light cure plus 7 days at 22 deg C/50% RH |
