Thermoplastic Polyurethane Resin: Solvent Adhesive TPU
Introduction
Solvent Adhesive TPU is a solid polyester-based TPU adhesive resin used to formulate solvent-based polyurethane adhesive systems. It is designed for applications where a soluble TPU resin is dissolved in a suitable solvent system and then applied by coating, spreading, laminating or other solution-based processes.
The basic process is:
This makes TPU for solvent-based adhesives suitable for applications requiring good bonding strength, peel strength, flexibility and controlled solution processing.
What Is Solvent Adhesive TPU?
Longyixing Solvent Adhesive TPU is a polyester TPU adhesive supplied as a solid resin rather than a finished solvent adhesive formulation.
The resin can be dissolved in suitable organic solvents to prepare a TPU solvent adhesive solution. The appropriate solvent system, TPU concentration and solution viscosity should be selected according to the substrate, coating process and final bonding requirements.
Compared with a ready-to-use liquid adhesive, using TPU resin for solvent-based adhesive formulations gives adhesive manufacturers greater flexibility in adjusting solvent systems, solid content, viscosity and processing conditions.
Solubility of TPU Adhesive Resin
TPU solubility is an important factor when selecting a resin for solvent-based polyurethane adhesive formulations.
This polyester-based TPU adhesive resin shows good solubility in several commonly used organic solvents. Based on the available technical data, the material is soluble in:
| Solvent | Solubility |
|---|---|
| DMF | Soluble |
| MEK | Soluble |
| Acetone | Soluble |
| Trichloromethane | Soluble |
| Ethyl Acetate | Soluble |
| Toluene | Soluble |
For formulations using MEK, a TPU solution can be prepared in MEK for coating and bonding applications. At 25°C, a 15% TPU solution in MEK is tested for viscosity. The actual solvent ratio, concentration and viscosity should be reasonably adjusted according to the specific formulation and application conditions.
Features of Solvent Adhesive TPU
The main features of this TPU adhesive resin include:
- High bonding strength for demanding adhesive applications.
- High peel strength for reliable bonding performance.
- Excellent solubility performance in commonly used organic solvents.
- Good extrusion consistency for consistent processing.
- Fast crystallization rate, supporting efficient processing.
- Good mechanical strength, with typical tensile strength of approximately 40 MPa.
- High tear strength, with a typical value of approximately 100 kN/m.
- Low activation temperature, with a minimum activation temperature of approximately 55–65°C.
- Fast tack-free performance, with a typical tack-free time of approximately 10 minutes.
These properties make the material suitable for both solvent-based adhesive formulations and selected thermoplastic adhesive applications.
How to Select Solvent Adhesive TPU
When selecting a TPU resin for solvent-based adhesive applications, several factors should be considered:
- Solvent compatibility – evaluate the solubility of the TPU in the selected solvent system.
- Solution viscosity – viscosity affects coating, spreading and application behavior.
- Solid content – adjust according to the required adhesive layer and application process.
- Bonding strength – compare performance using the actual substrate combination.
- Peel strength – evaluate resistance to peeling after bonding.
- Hardness and flexibility – select according to the flexibility and mechanical requirements of the finished product.
- Processing conditions – consider drying, activation temperature and production speed.
Applications of Solvent Adhesive TPU
Solvent Adhesive TPU can be used in a variety of adhesive and bonding applications.
Footwear Adhesives
TPU adhesive for footwear can be used for bonding applications involving shoe uppers, synthetic leather, textiles, foam and other flexible shoe components.
Hot Melt Films and Tapes
The polyester-based adhesive TPU can also be used in TPU adhesive for hot melt films and TPU adhesive for tapes applications. These applications can take advantage of the material's bonding strength, peel strength and thermoplastic processing characteristics.
Solvent-Based Adhesives
As a TPU solvent adhesive, the resin can be dissolved in a suitable solvent system and formulated for coating, spreading, laminating and other solution-based bonding processes.
Fire Hose Adhesives
The material can also be used for fire hose adhesive applications where TPU-based bonding materials are required.
Synthetic Leather and Textile Bonding
Soluble TPU resin can be used for flexible bonding and lamination of synthetic leather, textile and other flexible substrates.
Solvent Adhesive TPU vs. Hot-Melt Adhesive TPU
Solvent Adhesive TPU is processed through a solution system, while hot-melt TPU is generally applied by heating and activating the solid material.
Solvent-based systems can be useful for coating, spreading and liquid application processes, while hot-melt systems are attractive for applications requiring solvent-free processing and thermal bonding.
Both technologies can use TPU adhesive resin, but the appropriate TPU grade depends on the processing method, substrate and final application requirements.
Typical Properties
| Property | Typical Value |
|---|---|
| Density | 1.20 g/cm³ |
| Hardness | Shore A 95 |
| Viscosity, 15% in MEK at 25°C | 2500–3500 mPa·s |
| Tensile Strength | 40 MPa |
| Tear Strength | 100 kN/m |
| Crystallization Rate | Fast |
| Tack-Free Time | Approx. 10 min |
| Minimum Activation Temperature | 55–65°C |
The above values are typical reference values and should not be considered product specifications. Actual performance depends on formulation, processing conditions, substrate and end-use requirements.
Why Choose Longyixing Solvent Adhesive TPU?
Longyixing provides TPU adhesive resin for customers developing solvent-based polyurethane adhesive formulations.
We can help customers select suitable TPU solvent adhesive grades according to:
- Solvent system
- Required solution viscosity
- Substrate
- Bonding strength
- Peel strength
- Hardness and flexibility
- Coating or application process
- Final application
Contact us to request a suitable solvent adhesive TPU, technical data sheet or sample for your application.
