In the world of UV/EB curable resins, balancing high flexibility, fast cure speed, strong adhesion, and low temperature resistance is challenging. Most flexible resins suffer from slow surface cure (oxygen inhibition) or poor recovery after stretching.
T-7003 is a specialty polyurethane acrylate (PUA) that breaks these trade-offs. With an ultimate elongation >400%, fast LED cure, and glass transition temperature (Tg) as low as -52°C, it is designed for demanding applications:
IMD high‑stretch UV inks
Removable protective coatings (temporary masking)
Low‑temperature adhesives & seals (-40°C)
Elastic 3D printing & UV‑cured gaskets
Soft‑touch, recoverable elastic coatings
This article explores its key properties, formulation guidelines, and why it outperforms conventional resins for elastic, durable, and low‑energy‑curable systems.
Key Technical Parameters of T-7003
| Property | Value | Technical Significance |
|---|---|---|
| Tg (DSC) | -52°C | Remains elastomeric even at -40°C; excellent low‑temperature flexibility and fast recovery. |
| Molecular weight (GPC) | ~3500 | Balanced flexibility, cohesion, and adhesion; not too brittle. |
| Viscosity @60°C | 20,000 mPa·s | Suitable for hot‑melt or monomer/solvent dilution; good wetting. |
| Acid value | ≤3 mg KOH/g | High hydrolysis resistance; low metal corrosion. |
| Color (Gardner) | ≤2 | Water‑white; ideal for transparent clearcoats and pigmented inks. |
| Refractive index | 1.475 | Compatible with most acrylate monomers; minimizes haze. |
| Specific gravity | 1.05 | Standard density for easy formulation. |
These numbers explain why T-7003 handles extreme elongation, rapid LED curing, and long‑term durability in harsh environments.
Why T-7003 Excels Where Others Fail
1. Ultra‑High Elongation with Fast Recovery
Many soft resins simply deform permanently. T-7003's high cohesion and molecular design allow >400% elongation while returning to original shape quickly after stress is removed. This "recoverable elasticity" is critical for:
Stretchable IMD inks (in‑mold decoration)
Removable protective films that must not leave residue
Elastic seals that undergo repeated compression
2. Fast Surface Cure under Low‑Energy LED
Oxygen inhibition is a nightmare for thin elastic coatings. T-7003, when combined with a 184+MBF photoinitiator blend, achieves tack‑free surface cure even with low‑power 395nm LEDs. No need for inerting or high lamp intensity.
3. Excellent Adhesion & Hydrolysis Resistance
With acid value ≤3 and a polyurethane backbone, T-7003 adheres strongly to plastics (PC, PET, ABS), metals, and glass. It also resists moisture attack, making it suitable for:
Protective coatings on electronic components (transport/storage)
Low‑temperature adhesives for outdoor or refrigeration applications
4. Tunable Peel Strength (Removable vs. Permanent)
T-7003 itself offers high adhesion. However, by adding slip agents, waxes, or fillers (e.g., PTFE micro powders, silicone acrylates), formulators can reduce adhesion precisely to create removable / strippable coatings for temporary protection. This is ideal for:
Masking films during manufacturing
Protective peelable inks for glass or metal surfaces
Recommended Formulation Strategies
Monomer Selection – Stay Monofunctional
To preserve >400% elongation, avoid high‑functional monomers (TMPTA, DPHA). Use predominantly mono‑acrylates:
| Monomer | Role |
|---|---|
| AM-311 (PHEA) | Good cohesion, fast cure, high dissolving power |
| AM-312 (EOEOEA) | Soft film, improves plastic adhesion |
| AM-319 (TBCHA) | Flexible, excellent adhesion |
Thiol Additive – Thiol-18L (5–15%)
Increases surface cure (LED)
Acts as plasticizer / toughener
Higher loading → higher elongation
Chemically stable in storage (no premature gelation)
Photoinitiator System for LED
184 + MBF (e.g., 2+1 phr)
Anti‑oxygen inhibition
Clear, colorless cured film
Works with low‑intensity long‑wavelength LEDs (365–405nm)
Solvent Compatibility
Soluble in: esters, ketones, aromatic solvents
Not soluble in pure alcohols
Soluble in alcohol/ether blends (e.g., ethanol + PGME)
Application Spotlight
1. IMD High‑Stretch UV Inks & Temporary Protective Inks
T-7003 enables deep‑draw thermoformed inks that don't crack. For removable "peelable" inks, add 2–5% of silicone‑based release agent (e.g., Tego® Rad 2500) and matting agents to lower adhesion and improve scratch resistance.
2. Low‑Temperature Adhesives & Sealants (-40°C)
With Tg = -52°C, T-7003 remains flexible and impact‑resistant at -40°C. Ideal for:
UV‑cured elastic gaskets
Seals for refrigeration units
3D printed elastic parts that must survive freeze‑thaw cycles
3. Recoverable Elastic Coatings / Soft‑Feel Topcoats
Create a rubber‑like, fast‑recovery coating on plastic or metal. The coating can be deformed and returns to flush without permanent dent. Add matting agents for a soft‑touch texture.
4. Complex Elastic 3D Printing
T-7003 (with monofunctional monomers and Thiol-18L) provides excellent interlayer adhesion and low shrinkage for DLP/SLA printers targeting gaskets, cushions, and wearables.
Formulation Example: LED‑Curable High‑Elongation Clearcoat
| Component | phr | Function |
|---|---|---|
| T-7003 | 75 | Base resin |
| AM-311 (PHEA) | 15 | Reactive diluent, cohesion |
| AM-312 (EOEOEA) | 5 | Plasticization, plastic adhesion |
| Thiol-18L | 5 | LED surface cure + elongation |
| 184 | 2 | Deep cure |
| MBF | 1 | Surface anti‑oxygen inhibition |
| Flow agent (e.g., BYK‑333) | 0.3 | Wetting, leveling |
Cure condition: 395nm LED, 500 mJ/cm²
Performance:
Elongation at break: ~380%
Tensile strength: ~8 MPa
Recovery after 200% strain: >95%
No surface tack, passes cross‑cut adhesion on PC/ABS
For removable/strippable version: add 3% micronized PTFE wax + 1% silicone acrylate.
Frequently Asked Questions (SEO‑friendly)
Q1: Can T-7003 be used in pure alcohol‑based formulations?
No. It is insoluble in single alcohols but soluble in ester/ketone/aromatic solvents or alcohol‑ether blends.
Q2: How does it compare to standard polyurethane acrylates for low‑temperature use?
Most PUAs have Tg around -20°C to 0°C and become brittle below -30°C. With Tg -52°C, T-7003 stays flexible at -40°C, verified by low‑temperature impact and elongation testing.
Q3: Does Thiol-18L affect storage stability?
No. T-7003 + Thiol-18L blends are stable at room temperature for >6 months (no viscosity rise or gelation), thanks to the absence of basic or metallic contaminants.
Q4: Can I use T-7003 for UV pressure‑sensitive adhesives (PSA)?
Yes, with appropriate tackifiers and soft monomers. Its low Tg and high elongation are excellent for removable and low‑tack PSA.
Conclusion
T-7003 is a versatile, high‑performance polyurethane acrylate for engineers seeking extreme flexibility, fast LED curability, and durable adhesion in one resin. Whether you are formulating IMD inks, low‑temperature seals, stretchable 3D printing materials, or protective strippable coatings, T-7003 offers a unique combination of >400% elongation, -52°C Tg, and excellent surface cure under low‑energy LEDs.
For further technical support or sample requests, please contact your local UV resin supplier or resin distributor.