The liquid part of the ink composition is called the adhesive; Solids are pigments (pigments or dyes); And various additives. Adhesives are gel-like fluids with a certain viscosity. Its function was first as a carrier for pigments. Powdered pigment and other solid particles are mixed and connected, and the pigment is evenly dispersed in it by its wetting action, which makes fine grinding on the grinder easier; Second, as an adhesive, the pigment can eventually be fixed to the surface of the substrate, thus achieving the purpose of displaying characters, images, marks, decorations, etc. Also depending on its adhesion, ink can be transferred and transferred on the press. Finally, on printed matter, the adhesive also acts as a protective film, giving the necessary shine and even protecting the base.

The quality of the connecting material directly affects the performance of the ink, because the connecting material largely determines the viscosity, viscosity, dryness and fluidity of the ink. To get high quality ink, you must use a high quality adhesive. The various properties of ink adhesives determine the various uses of ink to suit its properties. Resins used for plastic gravure printing inks usually include chlorinated polypropylene, polyamide, polyurethane, etc. For a long time, chlorinated polypropylene has occupied more than half of the gravure composite ink resin market because of its low price and good adhesion to OPP. However, the biggest drawback is that the main solvent is toluene, which is usually an environmentally friendly solvent such as ester. Alcohol and alcohol don't help them. Solvent-based polyurethane ink adhesive has the advantages of easy to use, stable performance, strong adhesion, good gloss, good heat resistance, etc. It can be applied to various printing methods, especially suitable for screen printing, plastic packaging and laminated film.

On the other hand, foreign countries realized industrialization in the 1970s, such as Japan's Toyo Corporation, Otsuki Ink Chemical Industry and Takeda Pharmaceutical. Polyurethane ink adhesives used in China are usually imported from overseas and used in processing. The demand reached 30,000 tons. In recent years, many domestic production and research institutions are engaged in the research of polyurethane ink adhesive, and achieved good results. For example, 121°C and 135°C inking adhesives have been put into production and are widely used in the market, but the overall performance of the products has a certain gap compared with imported products. To improve the overall performance of the product and to develop multifunctional products is the focus of domestic research on polyurethane ink connection. Co., Ltd. based on the structural characteristics and functions of polyurethane, polyurethane ink binder for in-depth research, developed a good gloss, high cohesion strength, and pigment form a good phase of the product. Polyurethane ink connection materials have strong compatibility and good compatibility with alcohol solvents, which are put on the market to obtain a better response.

Les résines de polyuréthane utilisées dans les encres sont généralement constituées de polyester/polyéther polyols et d'isocyanates, et ont des forces moléculaires d'environ 20 000 à 40 000. Son solvant est principalement le benzène, la cétone, l'ester et d'autres solvants comme solvant principal. Dans le processus de recherche et développement, selon les exigences environnementales de l'usine d'encre et de l'imprimerie, vous pouvez utiliser un solvant d'ester de cétone ou un solvant d'ester d'alcool pour préparer la résine d'encre sans benzène correspondante.