Waterborne polyurethane resin and preparation method thereof

Abstract

The invention discloses waterborne polyurethane resin and a preparation method thereof, and belongs to the field of preparation of waterborne polyurethane. The waterborne polyurethane resin comprisesthe following components as raw materials in parts by weight: 30-40 parts of an NCO component, 50-115 parts of polyol, 8-10.5 parts of a chain extender, 0.05 part of a catalyst, 3.5 parts of a neutralizer and 180-230 parts of a solvent, wherein the polyol contains 20-30 parts of 12-hydroxystearic acid modified polyol; the chain extender contains 5 parts of a hydrophilic chain extender; the solventis a mixed solvent of one or more of propylene glycol methyl ether acetate, propylene glycol diacetate, propylene glycol methyl ether propionate, dimethyl carbonate, diethyl carbonate and dipropyl carbonate and deionized water. The waterborne polyurethane resin is prepared by a non-acetone method, has good stability and adhesion fastness to a plastic film, and is especially suitable for water-based ink for food package printing.

Description

technical field [0001] The invention belongs to the field of water-based polyurethane preparation, in particular to water-based polyurethane used for water-based ink. Background technique [0002] Water-based polyurethane is a new type of polyurethane system with water as the dispersion medium. It has the advantages of non-combustibility, no pollution to the environment, safe transportation, and safe use. It meets the requirements of national safety and environmental protection regulations, and the market demand is growing rapidly. [0003] Most water-based polyurethanes are prepared by self-emulsification of anions and cations. The viscosity of the prepolymer is relatively high when it is prepared, and it needs to be diluted with an organic solvent to reduce the viscosity. The commonly used solvents are acetone, N-methylpyrrolidone and other hydrophilic Non-toxic organic solvent, called acetone method (Chinese patent literature CN104031227A, CN103450440B, CN10217465B). In ...

AI Technical Summary

Problems solved by technology

[0004] Defects of the acetone method: Acetone is a precursor chemical and is classified as a strictly restricted raw material. The prepared water-based polyurethane needs to be distilled to remove acetone, which increases the operation steps and production costs.

The distilled mixed solvent of acetone and water cannot be reused, and can only be treated as hazardous waste, which requires high treatment costs (costs), and will inevitably cause secondary pollution to the environment during the treatment process

[0005] Defects of using methyl acetate, ethyl acetate and other solvents instead of acetone method: the prepared water-based polyurethane is unstable and easy to separate

Distilled mixed solvents such as methyl acetate, ethyl acetate, etc. and water cannot be reused, and can only be treated as hazardous waste, which requires high treatment costs (costs), and will inevitably cause secondary pollution to the environment during the treatment process

[0006] In particular, the water-based polyurethane resin prepared by the prior art has poor adhesion fastness to the plastic film of the prepared water-based ink, which cannot meet the requirements of the ink printing industry, and hinders the development of water-based ink.

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