Sealant
A sealant is a viscous material that changes state to become solid, once applied, and is used to prevent the penetration of air, gas, noise, dust, fire, smoke or liquid from one location through a barrier into another. Typically, sealants are used to close small openings that are difficult to shut with other materials, such as concrete, drywall, etc. Desirable properties of sealants include insolubility, corrosion resistance, and adhesion. Uses of sealants vary widely and sealants are used in many industries, for example, construction, automotive and aerospace industries.
The main difference between adhesives and sealants is that sealants typically have lower strength and higher elongation than do adhesives. Since the main objective of a sealant is to seal assemblies and joints, sealants need to have sufficient adhesion to the substrates and resistance to environmental conditions to remain bonded over the required life of the assembly.
Sealants are mainly used to fill openings, ensuring insulation against air, gas, noise or dust. The requested performances are slightly different from adhesives´ones, with higher elongation and lower strength.
Often used in outdoor applications, they must guarantee a long-term adhesion even in harsh environmental conditions.
Their field of application is multiple in Building & Construction, Automotive, Aerospace, Electronics and DIY industries.
SBC perfectly fulfill those requirements thanks to numerous benefits:
- Most tackifiers compatibility
- UV, ozone stability and weathering
- Excellent flexibility and elasticity at low temperatures
- Optimal strength/viscosity balance (blends possible)
- Excellent plasticizing retention for extended flexibility life
- Compatibility with a wide range of fillers to reduce formula costs
- Adhesion on most substrates.
Furthermore SEBS copolymers can be blended with asphalt and bitumen to formulate road and roofing compounds. The nature of such a asphalt blends provides the end-use product with optimized rheological properties, higher degree of elastomeric character and an improved shell life of the product in exterior environments.
| Components |
Parts by Weight |
| SEBS (Dynasol CH6120) |
11.93 |
| Indopol H-300 resin |
3.407 |
|
Pexalyn A-960 resin |
17.9 |
| CaCO2 |
21.48 |
| TiO2 |
7.16 |
| ZnO |
7.16 |
| Irganox 1010 |
0.05 |
| Epon 1002 |
0.23 |
| Cyasorb 1084 |
0.02 |
| Properties: |
| Hardness, Shore A |
18 |
| Tensile strength, psi |
320 |
| Elongation at break, % |
570 |
| Modulus at 100% elongation, psi |
40 |
Figure 1: White sealant formulation, with excellent elongation and cohesive strength
| Components |
Parts by Weight |
| |
A |
| Dynasol Calprene H-6110 |
100 |
| Regalrez 1018 resin |
270 |
| Endex 160 resin |
50 |
| Irganox 1010 |
1 |
| Tinuvin 770 stabilizer |
1 |
| Tinuvin PU stabilizer |
1.5 |
| Properties: |
| Tensile strength, psi |
343 |
| Modulus, psi |
46 |
| Elongation at break, % |
750 |
180° peel strength, pli, to:
- Glass
- Steel
- Aluminum
- Anodized aluminum
|
|
Figure 2: Sealant for different substrates, and excellent outdoor conditions resistance
| Components |
F-01
(PHR) |
F-02
(PHR) |
F-03
(PHR) |
F-04
(PHR) |
| Asphalt 150/200 |
93 |
88 |
93 |
88 |
| Calprene H6110 |
7 |
12 |
|
|
| Calprene H6120 |
|
|
7 |
12 |
| Properties ( Method) |
| Softening Point (°C) |
85 |
98 |
101 |
116 |
| Penetration @ 25°C 1/10mm |
72 |
44 |
72 |
36 |
| Viscosity @ 180°C (cPs) |
223 |
1021 |
334 |
1764 |
| Cold Flexiblity |
-20 |
-28 |
-20 |
-28 |
| Oven Ageing @ 200° C |
| Cold Flexivility @ 1 month (° C) |
|
-28 |
|
-30 |
| Softening Point @ 1 month (° C) |
|
96 |
|
122 |
| Cold Flexibility @ 6 month (°C) |
|
-28 |
|
-30 |
| Softening point @ 6 month (°C) |
|
99 |
|
122 |
Figure 3: Crack filler (Sealant) and Mopping formulations can include 3% to 12% in weight of SEBS in asphalt or bitumen mixes
