Preparation method of polyurethane resin for flexible packaging gravure table printing ink

Abstract

The invention discloses a preparation method of a polyurethane resin for flexible packaging gravure table printing ink and belongs to the field of ink material preparation. The preparation method comprises synthesis of polyester polyol: putting polybasic acid and dihydric alcohol into a reaction vessel according to a molar ratio and carrying out heating vacuum pumping to obtain polyester polyol, synthesis of a prepolymer, chain extension reaction: slowly adding a small molecule polyol chain extender into the repolymer and carrying out chain extension to obtain polyurethane resin, and production preparation: slowly adding ethyl acetate, anhydrous ethanol, modified resin and an assistant into the prepared polyurethane resin and preparing the polyurethane resin for flexible packaging gravure table printing ink. The preparation method has stable processes. The polyurethane resin is used as binding resin for preparation of ink so that ink pigment dispersibility, transparency and a drying rate are improved, ink printing adaptability, glossiness, shallow net transferability, base adhesion and frost resistance are improved, environmental friendliness is obtained and production and use demands are satisfied.

Description

technical field [0001] The invention belongs to the field of ink material preparation, and in particular relates to a preparation method of polyurethane resin used for flexible packaging gravure surface printing ink. Background technique [0002] At present, in the field of domestic flexible packaging plastic film printing, gravure plastic ink technology and market continue to develop, and its application scope covers almost all packaging fields, such as various plastic film substrate packaging in food, medicine, daily necessities and other industries. With the rapid development of the printing industry, the printing volume of various flexible packaging plastics continues to increase, and the requirements for product packaging grades are also getting higher and higher. [0003] Ink is mainly composed of four parts: binder resin, solvent, pigment and additives, among which ink binder resin plays a key role in ink performance. At present, the resins used in gravure surface pr...

AI Technical Summary

Problems solved by technology

It is understood that most of the polyurethane resins used in domestic inks have a solid content of about 30%, and the high ones can reach about 45%. However, their performance is average, the market competitive advantage is not obvious, and the technical level still needs further improvement. A considerable part of them uses benzene and ketones such as toluene, butanone, cyclohexanone, etc. as solvents. Toluene is highly toxic and may cause cancer if exposed to it for a long time; while butanone has a strong residual smell and has certain toxicity. , does not meet the requirements of environmental protection

For the resin used in water-based polyurethane ink, compared with oil-based organic solvent-based polyurethane ink resin, water-based polyurethane ink resin will not cause a large amount of volatilization of organic solvents, has low toxicity, and has little impact on the health of production workers. Environmental protection is becoming more and more important Today, water-based polyurethane resins have great prospects for development, but the development of water-based polyurethane ink resins is not as mature as solvent-based ink resins, and there are many deficiencies in many properties, especially for soft packaging gravure surface printing inks. Thermal stability, drying speed, water resistance and other properties are still not up to the standards of solvent-based, and it is difficult to break through the technology in the short term

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