LORD 7542B
Harmonization Code : 3919.10.80 | Other self-adhesive plastic rolls not exceeding 20 cm wide.
Main features
- 1:1 Fast-Cure Urethane Curative
- 5 to 10-Minute Working Time
- 30 to 60-Minute Handling Time
Product Description
LORD® 7542-B Urethane Adhesive Curative is Part 2 of the LORD 7542-A/B two-component structural urethane adhesive system. It must be combined 1:1 by volume with LORD 7542-A resin before use. LORD 7542-B is supplied as a tan or black liquid with a typical 7,000–14,000 cP viscosity at 25°C and 1234–1270 kg/m³ density. When mixed with LORD 7542-A, the system provides a typical 4–7 minute working time at 24°C, 1–2 hour handling-strength time, and full strength in 24 hours or less.
Key features
- Curative component for the LORD 7542-A/B structural urethane adhesive system
- Equal-volume 1:1 mixing with LORD 7542-A resin
- Shortest published process window among the B, C, and D curatives
- Suitable for cartridge or automatic meter/mix/dispense processing
- Supports FRP, SMC, CFRP, plastics, and prepared or coated metal bonding
- System-level typical tensile strength of 18.7 MPa with 70% elongation
- Documented system-level environmental resistance to humidity, salt spray, water, and temperature exposure
Applications
- Fast-cycle composite panel assembly
- Heavy-duty truck, service-truck, trailer, and vehicle-accessory bonding
- SMC, FRP, and CFRP structural joints
- Prepared or powder-coated metal-to-composite assemblies
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Thermal Properties
Additional Information
LORD® 7542-B Urethane Adhesive Curative
LORD 7542-B is Part 2 of 2 in the LORD 7542-A/B structural urethane adhesive system. It is not used alone. Combine it 1:1 by volume with LORD 7542-A resin to obtain the system's shortest published working window and a flexible cured adhesive for composite, plastic, and coated-metal assemblies.
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Tan or black liquid curative for equal-volume mixing
| Property | Typical value | Context |
|---|---|---|
| Component role | Curative, Part 2 of 2 | Must be combined with LORD 7542-A resin before use. |
| Appearance | Tan or black liquid | Colour depends on the commercial B-curative variant. |
| Viscosity at 25°C | 7,000–14,000 cP | Component viscosity; not mixed-system viscosity. |
| Density | 1234–1270 kg/m³ | Equivalent to 10.3–10.6 lb/gal. |
| Flash point | >93°C, closed cup | Does not eliminate decomposition, heated-process, or fire hazards. |
| Mix ratio | 1:1 by volume with LORD 7542-A resin | Use equal-volume cartridges or validated meter/mix equipment. |
Use only with LORD 7542-A resin at the documented 1:1 volumetric ratio
LORD 7542-A resin. LORD 7542-B is not a complete stand-alone adhesive.
4–7 minutes at 24°C using the supplier's 12.7 mm bead condition.
Approximately 1–2 hours at 24°C under the published test basis.
The mixed system reaches full strength in 24 hours or less at 24°C.
Prepare the substrates and combine 7542-B with 7542-A before the short work window begins
- Remove grease, dirt, moisture, release agents, and other contaminants.
- For plastics, use a dry-rag wipe or a validated solvent-dampened rag.
- For metals, the TDS recommends priming or powder coating.
- Use equal-volume cartridges or automatic meter/mix/dispense equipment.
- Level cartridge plungers before attaching the mixer.
- Purge at least one mixer length before applying adhesive to the substrate.
- Mate parts within the 4–7 minute working time.
- Clamp until the mixed system reaches handling strength.
- Maintain a typical 254–1016 µm bondline for optimum adhesion.
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Cure and final properties apply only after correct mixing with LORD 7542-A
Full system strength develops in 24 hours or less at 24°C.
Clean equipment and tools before cure with acetone or MEK. Do not use alcohol.
Heating the cured adhesive to approximately 149°C or above may soften it for separation; validate substrate heat resistance.
Painting and most cleaning processes are not expected to reduce bond strength under the supplier's system-level guidance.
Storage and industrial safety
The current US SDS identifies LORD 7542-B as an industrial urethane-adhesive curative with serious health and environmental hazards. It may be harmful if inhaled; cause skin and eye irritation; cause skin or respiratory sensitisation; damage fertility or the unborn child; damage the nervous system; and cause organ damage through repeated exposure. Use only with trained personnel, effective ventilation, suitable respiratory protection where required, protective gloves, eye and face protection, locked storage, and controls that prevent environmental release. Read the current regional SDS and package label before handling.
Do not assign final structural properties to LORD 7542-B curative by itself
LORD 7542-B is an uncured component. Final-state values apply only to a correctly metered, mixed, and cured LORD 7542-A/B adhesive system. DS3444 presents the bulk cured-property table at family level and does not explicitly identify the curative used.
| Property | Typical system-level value | Context |
|---|---|---|
| Hardness | 87 Shore A | ASTM D2240, Method A. |
| Tensile strength at break | 18.70 MPa | ASTM D638. |
| Elongation | 70% | ASTM D638. |
| Young’s modulus | 83.6 MPa | ASTM D638. |
| Glass-transition temperature | 46°C | ASTM D3418. |
| Moisture absorption | 1.65% | ASTM D570. |
Selected system-level room-temperature lap-shear results include 4.10 MPa on SMC, 17.90 MPa on e-coated steel, and 22.10 MPa on CFRP under the documented preparation, bondline, area, 1:1 mix, and 24-hour room-temperature cure.
Choose 7542-B when a shorter application window fits the production process
The LORD 7542-A/B system is positioned for SMC, FRP, CFRP, plastics, e-coated steel, powder-coated metals, truck and trailer structures, vehicle accessories, and other composite assemblies. Final qualification must address the short work window, equipment and mixer residence time, substrate and coating, bondline, joint geometry, clamping, peel, impact, fatigue, temperature, water and humidity exposure, painting, rework, and required failure mode.
LORD 7542-B selection, processing, and application guidance
Controlling technical data for LORD 7542-B curative, the required LORD 7542-A resin, process window, storage, system-level cured properties, and bond performance.
Open resourceFamily comparison covering LORD 7542 systems and curative-selection context.
Open resourceJoint design, substrate preparation, cartridge purging, bondline, fixturing, failure-mode, and rework guidance.
Open resourceGeneral structural-adhesive selection and market context.
Open resourceApplication context for service-body panels, compartments, roofs, and mixed-material structures.
Open resourceApplication context for utility and Class Eight trailer structures.
Open resourceValidate LORD® 7542-B with LORD 7542-A for your fast-cycle assembly
Krayden can help review 1:1 package and equipment configuration, mixer choice, 4–7 minute work time, substrate preparation, bondline, clamping, storage, safety controls, environmental durability, and final assembly qualification.
