Directly-compoundable low-melting-point polyester thin film preparation method for laminated steel

Abstract

The invention discloses a directly-compoundable low-melting-point polyester thin film preparation method for laminated steel. A core-layer polyester slice is formed by mixing 60 to 80 mass percent of pure polyester slice with a melting point of 180 to 230 DEG C and 40 to 20 mass percent of silicon dioxide additive type polyester slice. In order to avoid the degradation of PET (polyethylene terephthalate) in a melting extrusion process, the core-layer polyester slice is crystallized and dried, wherein primary crystallization is carried out at 80 to 120 DEG C for 12 hours; secondary crystallization is carried out at 150 DEG C; the drying is carried out at 160 DEG C for not less than 6 hours. According to the preparation method, a polyester thin film has the advantages of low melting point, high tensile property, high machinability, resistance to high-temperature cooking, high barrier property, nontoxicity, anti-falling performance and the like, is used as an inner layer and an outer layer of a steel food and medicament can, and can be disinfected and sterilized at high temperature; in addition, the polyester thin film is free of adhesives and chemical solvents, so that safety in use can be ensured.

Description

technical field [0001] The invention belongs to polyester films, in particular to a method for preparing a direct-composite low-melting-point polyester film for coated iron. Background technique [0002] The outer surface of traditional iron cans uses colored paint as the background color to print various exquisite patterns, while the inner surface is all painted with solvent-based paint to achieve anti-corrosion and anti-leakage functions. [0003] First of all, the paint used on the outer surface contains various solvents. During the processing, the solvent emission in the paint pollutes the air, and the paint needs to be dried in an oven during the processing, which consumes a lot of energy. BADGE (bisphenol-A diglycidyl ether) is commonly used as a heat stabilizer and reinforcing agent in interior surface coatings. The hydrogen chloride produced when PVC organosol is baked at high temperature combines with BADGE to form its chloropropanol derivatives. During the high-pr...

AI Technical Summary

Problems solved by technology

[0009] Compared with traditional tinplate printing and coating, the use of polyester film for coated iron has less carbon emissions and is conducive to environmental protection. The cost is 30% lower than that of traditional iron printing, and a large amount of solvent release is reduced; the traditional iron printing process needs to go through 3-6 times of drying processes, and if kerosene is used for combustion, a large amount of waste gas will be released

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