As global environmental regulations tighten and the demand for high-efficiency production continues to grow, UV curing technology has become a mainstream choice in industrial coating, printing, and adhesive applications due to its fast curing, low energy consumption, and solvent-free nature. Among these, UV-LED curing offers even lower energy use, longer light source life, and no ozone generation, accelerating the replacement of traditional mercury lamps. According to market data, the global UV-LED curing light source market reached approximately RMB 2.4 billion in 2025, with sales expected to hit RMB 2.7 billion in 2026, growing at a CAGR of about 9.2% from 2026 to 2032.
In UV-LED curing systems, resin as the core material directly affects coating adhesion, flexibility, curing speed, and final quality. T-7118 difunctional polyester acrylate resin, specifically designed for LED long-wavelength low-energy curing, delivers extremely low viscosity, fast curing, very low volume shrinkage, and excellent oxygen inhibition resistance. It is now driving breakthroughs across coatings, inks, and adhesives.
1. What is T-7118 Resin?
T-7118 is a difunctional polyester acrylate UV resin developed for LED long-wavelength low-energy curing of coatings and inks. It combines low viscosity with high reactivity, finding wide use in solvent-free UV spray coating, roller coating, UV inkjet printing, nail gel, and more.
With a hyperbranched molecular design, T-7118 has a molecular weight (GPC) of ~900 and a glass transition temperature (Tg) of -20°C, providing excellent low-temperature flexibility and impact resistance. 100% solids content makes it fully compliant with solvent-free coating requirements.
Key Technical Specifications
| Property | Typical Value |
|---|---|
| Viscosity (25°C) | 650 mPa·s |
| Molecular Weight (GPC) | ~900 |
| Glass Transition Temp (Tg) | -20°C |
| Elongation at Break | 45% |
| Acid Value | ≤2 mg KOH/g |
| Specific Gravity | 1.12 |
| Color (Gardner) | ≤1 |
| Solids Content | 100% |
*Source: T-7118 Technical Data Sheet*
2. Core Advantages of T-7118: Why Is It So Popular?
2.1 Extremely Low Viscosity – Breaking Application Barriers
T-7118's most notable advantage is its extremely low viscosity: only 650 mPa·s at 25°C, far lower than most competing products. This allows easy adaptation to high-precision inkjet printheads, ensuring stable droplet formation and accurate jetting.
More importantly, low viscosity means significantly reduced reactive monomer content in formulations. Traditional resins often require 30-60% diluting monomers to adjust viscosity, leading to higher shrinkage stress and VOC emissions. T-7118's low viscosity gives formulators greater flexibility, lowers raw material costs, and reduces irritation and VOCs for a safer production environment.
2.2 Fast Curing – Matches LED Low-Energy Processes
T-7118 achieves curing speeds comparable to high-functionality hyperbranched polyester acrylates, ensuring rapid surface drying even under LED long-wavelength low-energy conditions. This makes it an ideal fit for high-speed printing and continuous coating lines.
Test data shows surface drying times under 2 seconds, completely solving the problem of tacky surfaces caused by oxygen inhibition in traditional UV resins.
2.3 Ultra-Low Volume Shrinkage – No Warping or Cracking
Unlike conventional resins that exhibit large shrinkage upon curing, T-7118 maintains very low volume shrinkage. This provides:
Coatings that resist warping, cracking, or adhesion loss due to shrinkage
Excellent dimensional stability for precision printing and thin-film applications
No curling in paper overcoating
2.4 Excellent Oxygen Inhibition Resistance
Under LED light, atmospheric oxygen rapidly quenches free radicals, reducing surface cure efficiency and leaving a sticky uncured layer – the oxygen inhibition effect. T-7118's molecular design enables rapid, complete surface curing even in air, ensuring dry, tack-free prints for high-speed continuous printing operations.
2.5 Superior Adhesion
T-7118 excels in adhesion performance. Its molecular structure optimizes interfacial bonding to various substrates – metal, plastic, wood, paper, and flexible films. For nail gels, it offers excellent adhesion to human nails. In inkjet printing, it firmly adheres to PVC, glass, ceramics, and many other materials.
2.6 Good Flexibility
With 45% elongation at break, T-7118 provides excellent flexibility and impact resistance, especially for flexible substrates like films and paper. The -20°C Tg ensures low-temperature flexibility.
2.7 Broad Compatibility
T-7118 shows good miscibility with common monomers (TPGDA, HDDA, etc.) and solvents (alcohol, ether, ketone, aromatic hydrocarbon mixtures). It is compatible with polyester, epoxy, polyurethane, phosphate ester, and acrylate resins, giving formulators maximum flexibility.
3. Main Applications of T-7118
3.1 UV Inkjet Printing Ink – Core Material for High-Precision Printing
In UV inkjet printing, T-7118 as a main resin delivers outstanding overall performance.
Key Advantages:
Low acid value (≤2 mg KOH/g) – non-corrosive to precision printheads, extending equipment life
Excellent pigment wetting – ensures vibrant, uniform colors, reduces settling, improves print clarity and saturation
Fast surface drying – meets low-energy high-speed LED printing processes for industrial continuous production
Multi-substrate adhesion – reliably adheres to metal, glass, plastic, etc.
Typical Applications: industrial signage, packaging printing, personalized customization, decorative materials, and other high-precision printing.
3.2 Nail Gel – Preferred Resin for Premium Manicure Products
In the nail industry, T-7118 resin has become an ideal choice for nail gel formulations thanks to its low viscosity and high reactivity.
Key Advantages:
Fast LED curing – matches nail lamps (395nm wavelength), fully cures in tens of seconds
Soft film formation – low viscosity gives thin, uniform, comfortable feel
Excellent adhesion to nails – can be used as main resin for base coats or to replace monomers in top coats
High safety – low shrinkage reduces risk of nail lifting; HEMA-free, lower allergenic potential
45% elongation at break – adapts to daily nail flexing, long-lasting without peeling
Applications: base coat main resin, monomer replacement in top coats, adhesion promoter in color gels.
3.3 Solvent-Free UV Coatings – Ideal for Green Finishing
In wood coatings, film coating, and paper roller overprint varnishes, T-7118's solvent-free nature fully replaces traditional VOC-containing coating systems.
Key Advantages:
Solvent-free, zero VOC – 100% solids meets environmental regulations
Low-energy curing – adapts to high-speed printing processes for continuous production with reduced energy consumption
Good surface cure – rapid curing even in thin films, avoiding tacky surfaces from oxygen inhibition
Low shrinkage – prevents stress cracking or adhesion loss
Adjustable gloss – by varying monomer ratio, matte or high-gloss finishes are achievable
Typical Applications: LED-cured solvent-free spray wood coatings, film and paper roller varnishes.
3.4 UV Adhesives – Bonding Solutions for Electronics & Personal Care
In UV adhesives, T-7118's excellent adhesion to human nails and low shrinkage make it an important resin for nail gel adhesives, electronic component encapsulation, etc. Its fast curing meets LED low-energy requirements, boosting productivity.
3.5 T-7118 Series Derivative Grades – Tailored Solutions
To meet different application needs, the T-7118 series offers specialized derivative grades:
T-7118F (Flexibility Enhanced) :
Better weather resistance, non-yellowing
Even better flexibility and adhesion than the standard grade
Elongation at break up to 65% (vs 45% for standard)
Ideal for high-bending applications like films, flexible substrates, and nail gels requiring extra soft feel
T-7118D (Boiling Water Resistance Improved) :
Enhanced resistance to boiling water vs standard grade
Suitable for applications requiring some humidity/weather resistance
Performs well in UV metal printing coatings
4. Industry Trends & Strategic Value of T-7118
4.1 Rapid Adoption of UV-LED Curing Technology
The global UV-LED curing market is growing rapidly. In 2025, global UV-LED curing light source sales were ~RMB 2.4 billion, expected to reach RMB 4.5 billion by 2032 at a CAGR of ~9.2%. UV-LED systems offer mercury-free, low ozone, instant start, low heat, and precise wavelength control, accelerating replacement of traditional mercury lamps.
4.2 Environmental Regulations Driving Solvent-Free Transition
Under carbon peaking and neutrality goals, waterborne, solvent-free, and light-curing eco-friendly products are gaining share. The UV curing materials industry is undergoing structural transformation: LED curing is spreading, increasing demand for low-energy, high-reactivity resins; tighter regulations drive low-migration, low-irritation materials.
T-7118's 100% solids solvent-free design requires no high-temperature baking, cutting energy consumption by >50% compared to conventional processes, with zero VOC emissions – supporting green manufacturing.
4.3 Digital Transformation in Inkjet Printing
At the 2026 Canton Fair, industrial inkjet automation equipment became a focal point, with global buyers shifting from traditional production to digital inkjet solutions. UV inkjet inks combine digital printing flexibility with UV's fast curing, low VOC, and high performance – a key green printing material. T-7118 as an ideal main resin for UV inkjet inks aligns perfectly with this technological shift.
4.4 Health & Eco Trends in Nail Gel
Market data shows global long-wear nail gel demand increased from 35% in 2020 to 58% in 2025. Gen Z consumers' preference for "low-maintenance, high-safety" manicure products drives the industry toward healthier, more eco-friendly solutions. T-7118's low shrinkage, flexible film, and HEMA-free characteristics perfectly match this transformation.
5. T-7118 vs Conventional UV Resins: Performance Comparison
| Performance Factor | T-7118 | Conventional Resin |
|---|---|---|
| Viscosity (25°C) | 650 mPa·s (very low) | Typically higher, requires large monomer dilution |
| LED low-energy curing | ✅ Fast cure, good surface drying | Usually requires higher energy |
| Volume shrinkage | Very low | High, prone to warping/cracking |
| Oxygen inhibition resistance | Excellent, tack-free surface | Often surface tacky |
| Monomer usage | Significantly reduced | Needs 30-60% diluting monomers |
| VOC emissions | Solvent-free, zero VOC | VOC risk |
| Flexibility | 45% elongation at break | High-functionality resins often brittle |
| Adhesion | Excellent on many substrates | Poor on some substrates |
| Pigment wetting | Excellent | May need extra dispersants |
| Equipment safety | Low acid value, non-corrosive | High acid value may damage equipment |
| Safety (nail gel) | HEMA-free, low allergy risk | May contain HEMA and other allergenic monomers |
*Source: T-7118 technical data & industry literature*
6. Formulation Recommendations
6.1 UV Inkjet Ink
Use T-7118 as the main resin, leveraging its low viscosity and excellent pigment wetting. Recommended addition level: 40-70%. Low acid value ensures printhead safety. Combine with appropriate monomers (TPGDA, HDDA) and photoinitiators for a complete LED-curable inkjet formulation.
6.2 Nail Gel
As a base coat main resin, recommended T-7118 content: 50-80%. Its excellent adhesion, low shrinkage, and flexible film formation allow reduction or replacement of traditional HEMA monomers. In top coats, replacing some monomers with T-7118 significantly improves flexibility and gloss retention while lowering overall VOC and irritation.
6.3 UV Coatings
T-7118 can be blended with common monomers (TPGDA, HDDA, etc.) and is compatible with polyester, epoxy, polyurethane, and other polymers, allowing tunable coating properties. Adjust monomer ratios to achieve matte or high-gloss finishes. Note: the resin is not soluble in pure alcohol solvents but dissolves well in alcohol-ether mixtures.
6.4 Choosing T-7118F or T-7118D
For extreme flexibility requirements – flexible films, soft-feel nail gels → T-7118F (65% elongation at break)
For high boiling water resistance – outdoor or humid environments → T-7118D
For balanced all-round performance – standard T-7118 meets most needs
7. Frequently Asked Questions
Q1: What light sources is T-7118 suitable for?
A: T-7118 is designed for LED long-wavelength low-energy curing, especially 365nm, 385nm, and 395nm LEDs. Full cure can be achieved at 80-120 mJ/cm².
Q2: What is the biggest advantage of T-7118 over traditional UV resins?
A: The unique combination of low viscosity + fast cure + low shrinkage. Low viscosity reduces monomer usage and shrinkage stress; fast cure meets LED low-energy demands; low shrinkage prevents warping/cracking – these three are rarely achieved together.
Q3: Is T-7118 safe for nail gel use?
A: Yes. T-7118 is HEMA-free and does not contain high-risk photoinitiators like TPA. Low shrinkage reduces nail lifting risk, and it provides a soft film with excellent adhesion to nails, making it a premium choice for high-end nail gels.
Q4: What is the difference between T-7118F and T-7118D?
A: T-7118F offers enhanced flexibility (65% elongation vs 45% for standard), ideal for high-bending applications. T-7118D provides improved boiling water resistance for outdoor or humid environments.
Q5: Is T-7118 soluble in alcohol solvents?
A: T-7118 is not soluble in pure alcohol but dissolves well in alcohol-ether mixtures, offering formulation flexibility.
Q6: What is the storage stability of T-7118?
A: T-7118 has good storage stability when kept sealed, away from light, at room temperature. Store in a cool, dry place away from direct sunlight and high temperatures. Use promptly after opening.
Conclusion
T-7118 difunctional polyester acrylate resin overcomes the pain points of traditional UV resins – high energy consumption, high shrinkage, and environmental concerns. From the process convenience of low viscosity, to the production efficiency of high reactivity, to broad formulation compatibility, this product offers a cost-effective solution for eco-friendly coatings.
As UV-LED curing technology spreads and demand for sustainable materials grows, T-7118 – with its low viscosity, high reactivity, and wide substrate adaptability – not only meets current technical needs but also provides a foundation for next-generation high-solids, low-energy coatings. In an era where green manufacturing and high efficiency go hand in hand, T-7118 is a key enabler of industry upgrade.