The roles of water-based polyurethane resin in printing ink

The roles of water-based polyurethane resin in ink include enhancing adhesion, improving yellowing resistance, and adjusting viscosity, among others. Next, I will explore in detail the various functions and application effects of water-based polyurethane resin in ink:

Enhancing Adhesion

• Description: According to search results, the molecular structure of water-based polyurethane resin contains strong groups such as carbamate and allophanate, which can form hydrogen bonds with corresponding strong groups on the surface of plastic substrates. The formation of these chemical bonds strengthens the connection between the ink and the printing material, thereby improving the adhesion of the ink on various substrates.

• Application Effect: In practical printing, this means that inks added with water-based polyurethane resin can adhere more firmly to plastic surfaces such as polyester and polyamide, reducing the risk of ink peeling or fading, and improving the quality and durability of the print.

Improving Yellowing Resistance

• Description: Waterborne polyurethane possesses excellent resistance to yellowing due to the use of aliphatic polyesters and aliphatic isocyanates as main raw materials during manufacturing, which have high stability to light and heat and are not prone to yellowing.

• Application Effect: Using this type of resin in inks, especially in applications requiring long-term color vibrancy and prevention of fading (such as outdoor advertisements and high-end packaging materials), can significantly enhance the product's durability and market competitiveness.

Adjusting Ink Viscosity and Leveling

• Description: Water-based polyurethane resin can adjust the viscosity and leveling of the ink through its unique intermolecular forces. Most water-based polyurethane resins do not contain reactive NCO groups, but rely on polar groups within the molecule to generate cohesion and adhesion for curing.

• Application Effect: This makes the ink easier to blend and control during use, ensuring excellent printing results under different printing conditions, while also reducing ink penetration and diffusion problems, improving the clarity and precision of the image.

Optimizing Gloss and Color Development

• Description: Water-based polyurethane resin can improve the gloss and color development of the ink. Due to its good film-forming ability and transparency, it can form a uniform, continuous thin film after printing, helping with the even distribution of pigments and reflection of light.

• Application Effect: This characteristic enables printed products to exhibit more vivid, bright colors and higher gloss, especially suitable for high-quality picture books, posters, and packaging boxes that require high visual effects.

Environmental Protection and Safety

• Description: Compared with traditional solvent-based inks, water-based inks use water as the main solvent, significantly reducing the use of organic solvents. This not only lowers the emission of harmful substances but also reduces the risk of fires and explosions, meeting the dual requirements of environmental protection and safety in modern printing.

• Application Effect: Using water-based polyurethane resin in inks can help enterprises achieve green printing, meeting increasingly stringent environmental protection standards and consumers' preferences for green consumption.

Enhancing Overall Printing Performance

• Description: The comprehensive properties of water-based polyurethane resin make it an important component in ink formulations. It not only enhances single properties such as adhesion or yellowing resistance but also comprehensively improves the overall performance of the ink through its unique chemical and physical properties.

• Application Effect: This allows water-based polyurethane resin to be widely used in the production of various types of inks, from common writing and printing inks to specialty inks such as UV and LED inks, where its application can be seen.

In summary, water-based polyurethane resin plays an indispensable role in ink manufacturing, not only enhancing basic ink properties such as adhesion and durability but also optimizing environmental and safety performance, meeting the high-standard needs of the modern printing industry. Therefore, mastering the correct use and blending techniques of water-based polyurethane resin is particularly important for ink manufacturers.