Coating liquid for barrier layer, preparation and barrier film thereof

Abstract

The invention discloses a coating liquid for a barrier layer, preparation and a barrier film thereof. The coating liquid comprises the following components in parts by mass: 0.4-20 parts of a carboxyl-containing polymer (A), 0.20-5.0 parts of a hydroxyl-containing water-soluble polymer (B), 0.01-3 parts of a coupling agent (C) with carboxyl reactive groups, 1.7-13 parts of a hydrolytic condensateof metal alkoxide (L) and 30-95 parts of a solvent. According to the invention, a carboxyl-containing polymer (A) is used as a main agent, and excellent gas-blocking and water-blocking properties areshown after two-step modification of ester crosslinking and inorganic hybridization; and the barrier film disclosed by the invention is realized through coating, is simple in preparation process, highin production efficiency and low in cost, and can be applied to the fields of food packaging, medicine packaging, flexible packaging of photoelectric devices and the like.

Description

Technical field: [0001] The invention relates to the field of film technology, in particular to a coating solution for a barrier film. Background technique: [0002] In order to avoid the deterioration of the contents of the package and maintain its function and performance, the packaging materials used for flexible packaging of food, medicine and optoelectronic devices are required to prevent the deterioration of the contents of the package caused by the passage of gases (especially oxygen, water vapor, etc.) through the packaging materials. performance. Therefore, packaging materials are required to have sufficiently low gas barrier properties. [0003] In recent years, people have been actively developing transparent packaging materials with excellent gas barrier properties and fragrance retention. At present, film materials with a barrier layer formed of inorganic oxide films such as silicon oxide and aluminum oxide are commonly used. The thin film material of this typ...

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Problems solved by technology

[0006] Chinese patent CN200980113160.4 proposes coating metal alkoxide-modified polyacrylic acid barrier coatings on both sides of the base film, then dip-coating in a multivalent metal ion solution after high-temperature treatment, and then performing high-temperature treatment again treatment to form an ion cross-linked layer between the modified polyacrylic acid coating and the metal ions, and prepare a film material with excellent barrier properties. This method requires multiple coating processes, dip coating processes and high-temperature treatment processes, and the process is complicated. , the cost is higher, and it is not conducive to the technical promotion of the product

Since the zinc oxide in the inorganic oxide coating is covered by two-component polyurethane, it shows poor affinity with the modified polyacrylic acid coating, which affects the compactness between the coating interfaces, and because the polyacrylic acid is flexible The macromolecular chains of zinc oxide can only be neutralized and modified by introducing zinc oxide, and the effect is not obvious; so this type of gas barrier film cannot achieve the water and oxygen barrier performance of vacuum coating barrier technology

[0008] In summary, barrier coating technology is simpler than vacuum coating barrier technology, but there is still a big gap in gas barrier performance compared with vacuum coating barrier technology

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