CHO-BOND® Conductive Caulks and Sealants
CHO-BOND caulks and sealants are electrically conductive epoxy, silicone and acrylic resins. Their purpose is to provide effective EMI/EMP shielding and sealing, filling larger gaps than do adhesives. Caulks are available as one-component, non-hardening systems or two-component, curing systems. Some CHO-BOND caulks have excellent oxide layer bite-thru. They can be dispensed with conventional caulking guns.
Rigid Epoxies
CHO-BOND two-component epoxy caulks are filled with silver-plated-copper. They provide excellent adhesion to dissimilar substrates. These epoxy systems can be used in lap or butt joint applications, but should be used only if the seam will not be broken. CHO-BOND 360-208 epoxy does not require contact pressure during cure.
Silicones and Flexible Polyisobutylenes
One-component, non-hardening sealants are formulated to shield or seal joints and seams likely to be disassembled or subject to vibration or warping. A key feature is their capacity to remain adherent without cracking or pulling away from the surface. These CHO-BOND sealants are silver-plated-copper-filled silicone or polyisobutylene filled with silver-plated-glass, silver-plated-copper, or silver-plated-aluminum. Metallic surfaces may require priming with CHO-BOND primer to promote better adhesion of the silicone caulks. CHO-BOND 1038 and CHO-BOND 1075 compounds may be used as fillet seals. All other polyisobutylene and silicone materials require contact pressure to develop their electrical properties.
Corrosion-Resistant Sealants
Chomerics pioneered silver-plated-aluminum particle technology to minimize the galvanic corrosion effects of conductive elastomer gaskets. This highly conductive filler is also used in our CHO-BOND 1075 sealant. The Ag/Al particle will provide a more compatible system for aluminum flanges.
Extensive testing conducted at Chomerics and by the USAF has shown reduced corrosion at joints while EMI shielding performance is maximized. Standard specifications have been developed for these Ag/Al filled silicone sealants. Additional testing includes: corrosion-resistance to MIL-STD-810 salt fog; long-term effects on both physical and electrical properties; paintability; lightning survivability; and NASA outgassing. Technical bulletins for these products are available on request.
| Specifications and Product Characteristics (Contact Chomerics for complete specifications and test procedures) |
||||||||
|---|---|---|---|---|---|---|---|---|
| CHO-BOND Adhesive | 360-20 | 360-208 | 1035* | 1038* | 1075*** | 4660 | 4669 | 1086 |
| Binder | epoxy | epoxy | silicone | silicone | silicone | polyiso-butylene | polyiso-butylene | primer for 1035, 1038 |
| Filler | Ag/Cu | Ag/Cu, Ag | Ag/glass | Ag/Cu | Ag/Al | Ag/Cu | Ag/CU | |
| Mix Ratio (by wgt.) | 1:1 | 100:33 | 1-part | 1-part | 1-part | 1-part | 1-part | 1-part |
| Consistency | Medium paste | very thick | thin paste | medium paste | medium paste | gritty paste | gritty paste | thin fluid |
| Specific Gravity | 5.0 ± 0.30 | 4.0 ± 0.40 | 1.9 ± 0.10 | 3.55 ± 0.35 | 2.0 ± 0.25 | 2.0 ± 0.30 | 2.0 ± 0.30 | 0.78 ± 0.10 |
| Minimum Lap Shear Strength, psi (MPa) | 1600 (11.04) | 1400 (9.66) | 100 (0.69) | 120 (0.83) | 100 (0.69) | N/A | N/A | N/A |
| Maximum DC Volume Resistivity, ohm-cm | 0.005 | 0.01 | 0.05 | 0.01 | 0.01 | 0.08 | 0.08 | N/A |
| Use Temperature | -80 to 212°F(-62 to 100° C) | -80 to 212°F(-62 to 100° C) | -67 to 392°F(-55 to 200° C) | -67 to 257°F(-55 to 125° C) | -67 to 392°F(-55 to 200° C) | -67 to 212°F(-55 to 100° C) | -67 to 212°F(-55 to 100° C) | -112 to 392°F(-80 to 200° C) |
| Elevated Temperature Cure Cycle | 2.0 hrs. @ 150°F (66°C) | 0.75 hrs. @ 212°F (100°C) | N/A | N/A | N/A | N/A | N/A | N/A |
| Room Temperature Cure Time | 24 hrs. | 24 hrs. | 1 wk.** | 1 wk.** | 1 wk.** | 1 wk.** | 1 wk.** | 0.5 hr. |
| Working Life | 1.0 hr | 1.0 hr | 0.5 hr. | 0.5 hr. | 0.25 hr. | 0.5 hr. | 2.5 hr. | N/A |
| Shelf Life, mos. | 9 | 9 | 6 | 6 | 6 | 6 | 6 | 6 |
| Coverage, in2/lb. (cm2/g) | 500 (7.1) | 700 (9.9) | 1500 (21.3) | 750 (10.6) | 1200 (17.0) | 900 (12.8) | 900 (12.8) | N/A |
| Recommended Thickness, in. (cm) | 0.010 min. (0.03) | 0.010 min. (0.03) | 0.007 min. (0.02) | 0.007 min. (0.02) | 0.010 min. (0.03) | 0.015 min. (0.04) | 0.015 min. (0.04) | 0.0002 max (0.001) |
| Product Notes | |
|---|---|
| 360-20 | Large particle size allows for thick bond-lines and oxide layer bite-thru. |
| 360-208 | Large particle size allows for thick bond-lines and oxide layer bite-thru. No contact pressure required. |
| 1038 | Maximum EMI performance. Excellent fillet in military environment. Non-corrosive, room temperature cure system. No maximum thickness limits. |
| 1075 | For bonding Ag/Al conductive elastomers. |
| 4660 | Resists acids, alkalis, salts. Attacked by oxidizing agents and halogens. Best applied before assembly. Remains flexible. |
| 4669 | Same as 4660, but longer working life. |
| 1086 | Wipe on surface and let air dry 30-60 min. |
| Product | Ordering Part Number | Unit/Size |
|---|---|---|
| CHO-BOND 360-20 CHO-BOND 360-208 CHO-BOND 360-208 |
50-01-0360-0200 50-01-0360-0208 50-00-0360-0208 |
1 pound kit (0.5kg) 1 pound kit (0.5kg) 3 ounce kit (85 g) |
| CHO-BOND 1035 CHO-BOND 1035 |
51-01-1035-0000 51-00-1035-0000 |
10 ounce kit (0.3 kg) 2.5 ounce kit (71 oz) |
| CHO-BOND 1038 CHO-BOND 1038 |
50-01-1038-0000 50-02-1038-0000 |
1 pound kit (0.5kg) 4 ounce kit (113.4 g) |
| CHO-BOND 1075 CHO-BOND 1075 |
50-01-1075-0000 50-02-1075-0000 |
10 ounce kit (0.3 kg) 2.5 ounce kit (71 g) |
| CHO-BOND 4660 CHO-BOND 4660 |
51-05-4660-0000 51-02-4660-0000 |
1.5 pound cartridge (0.7 kg) 4 ounce tube (113.4 g) |
| CHO-BOND 4669 CHO-BOND 466 |
51-05-4669-0000 51-02-4669-0000 |
1.5 pound cartridge (0.7 kg) 4 ounce tube (113.4 g) |
| Primers CHO-BOND 1086 |
50-01-1086-0000 | 1 pint (0.47 L) |
Note: Custom packaging can be accommodated. Please inquire.
Every shipment of Chomerics’ conductive compounds is accompanied by a Certificate of Conformance to Chomerics specifications. Additional test reports can be obtained for a service charge. Quality control procedures conform to MIL-I-45208.