Polyfunctional Aziridine Crosslinking Agent

Polyfunctional aziridines are very versatile molecules with wide-ranging usage in coatings and adhesive applications. These cross-linkers are used to improve physical and chemical properties for both aqueous and non-aqueous coatings, as well as a variety of adhesives.

TAILAI is dedicated to providing a complete line of polyfunctional aziridine cross-linkers and creates a unique partnership with customers to provide necessary technical support. PolyAziridine is committed to being the source of this technology in the cross-linker market.

aziridine crosslinking agent is a special class of compounds, it is easy to react with carboxylic acid groups, cross-linking, used as crosslinking agent, adhesion promoter and modifier, the polyaziridine is generally used for the crosslinking agent of acrylate emulsion and polyurethane emulsion, and can also be used for non-aqueous resin. It can significantly improve the final performance of adhesives, coatings and printing inks, and improve the strength, flexibility, solvent resistance, water resistance, hardness and adhesion to the substrate.

these kinds of aziridine crosslinking agents are slowly added to the coating system with uniform stirring before use, this corresponds to the aziridine as a crosslinker component of the two-component coating. It may be added directly or after dilution with an active hydrogen-free solvent or water. The addition amount depends on the performance requirements of the coating, and is generally 1% to 3% of the resin solid content, and 5% can be added. After curing, a coating with higher solvent resistance is formed. The effect of pH value on the crosslinking rate was higher. When the pH value of the emulsion was controlled at 9.0~9.5, the best effect could be obtained by adding the multi-component aziridine crosslinking agent. A lower pH may cause the aziridine to react too fast. Generally, the reaction can be carried out at room temperature, and heating is advantageous to the reaction.
after the addition of aziridine, the pot life of aqueous systems containing low-boiling amines such as ammonia or triethylamine is usually 18~36H, beyond this time, the effective aziridine group is lost, only need to add, it is stated that there is no negative effect on the performance of the adhesive film. Aziridine compounds are sensitive to active hydrogen groups and cannot be contacted with acidic substances and strong oxidants.

The addition amount is usually 1-3% of the solid content of the emulsion, and the pH value of the emulsion is 8~9, avoid using in acidic medium (pH <7).
This product mainly occurs cross-linking reaction with carboxyl groups in the emulsion, and can also occur cross-linking reaction with amine groups and hydroxyl groups under strong acid catalysis. Therefore, aprotic organic bases should be used as much as possible when adjusting the pH value of the system;
This product can be cross-linked at room temperature, but the baking effect is better at 60-80 degrees;
This product is a two-component type cross-linking agent, once added to the system should be used within two days, otherwise it will form a gel phenomenon;
This product can be miscible with water and common solvents, therefore, usually, it can be directly mixed into the system under vigorous stirring, or it can be dissolved in water and solvent before being added into the system;
The product has a slightly irritating ammonia taste, long-term inhalation will cause Cough, runny nose, presenting a false cold symptoms; Skin contact will cause skin swelling according to different people's resistance, generally in 2~6 days can disappear, severe cases should be prescribed treatment. Therefore, care should be taken to avoid direct contact with the skin and eyes, and use in a ventilated environment. Spray should pay special attention to the mouth, nose inhalation, should wear a special mask operation.