Waterproof scratch-resistant waterborne polyurethane coating and preparation method thereof

Abstract

The invention discloses a waterproof scratch-resistant waterborne polyurethane coating and a preparation method thereof. The coating comprises the following components in parts by weight: 5-12 parts of polyisocyanates, 5-12 parts of polyether or polyester polyol, 1-4 parts of organosilicon polyol, 8-14 parts of solvents, 1-3 parts of a hydrophilic chain-extender, 1-3 parts of a small molecule chain extender, 1-3 parts of a neutralizer and 50-70 parts of water. Due to the reaction between the organosilicon polyol and polyisocyanates, organosilicon components are introduced into polyurethane emulsion, so that the water resistance and smoothness of the coating are obviously improved; compared with general waterborne coatings, due to the introduced organosilicon polyol, the surface energy of the coating film is reduced, and the coating is endowed with good solvent resistance; and compared with an additive type organosilicon aid, the organosilicon polyol and polyisocyanates are reacted and grafted into a molecular chain, and the coating is endowed with high storage stability.

Description

technical field [0001] The invention relates to the technical field of transfer coatings, in particular to a waterproof and scratch-resistant water-based polyurethane coating and a preparation method thereof. Background technique [0002] my country's cigarette pack printing technology has high requirements for craftsmanship, which has far exceeded that of developed countries in Europe and the United States. The early gold and silver cardboard used in the packaging boxes of tobacco, alcohol, food, daily necessities, etc. was mainly produced by the composite method, that is, the aluminum foil or aluminized film is directly composited with the paper. The aluminum foil and plastic film used in the product cannot be recycled, causing resource waste and environmental pollution. In order to protect the environment and save costs, the direct plating process and the transfer process are now mostly used. Compared with the direct plating process, the advantages of the transfer proce...

AI Technical Summary

Problems solved by technology

At present, there are two main problems in the transfer of water-based polyurethane coatings from cigarette packs: because water-based transfer coatings are easier to absorb moisture than solvent-based coatings, and have poor water resistance; The difference is large, resulting in poor abrasion resistance and easy scratching of water-based coatings

However, even if the method of addition polymerization is adopted, the compatibility of polysiloxane (PMDS) and polyurethane is limited, and the use of a large amount of polysiloxane will have a very serious impact on the leveling and light transmittance of the coating.

Images