Coating liquid for preparing high-barrier anti-boiling film and preparation method thereof

Abstract

The invention discloses a polyvinyl alcohol coating liquid for preparing high-barrier anti-boiling film, made from, by weight, 3-12 parts of polyvinyl alcohol, 75-95 parts of water, 0.6-3.5 parts of acrosslinker, 0.1-2 parts of a defoaming agent, 0.1-1 part of a leveling agent, 0.05-1 part of a dispersing agent, 0.01-0.5 part of a catalyst, 5-15 parts of an adjusting agent, and 0.1-3.0 parts of nanoparticles. Compared with the prior art, the coating liquid and the preparation method thereof have the advantages that the coating liquid is present in high-transparency low-viscosity state, has weak acidity, never corrodes equipment and is environmentally friendly, and the process is simple; a coating layer has small thickness, high drying speed, high strength of bonding with base surface, andexcellent barrier performance; the coating liquid has stable viscosity, has no significant change in viscosity within 2 months; the coating liquid has excellent water resistance, and after boiling at100 DEG C for 60 min, barrier performance of coating film can be maintained well.

Description

technical field [0001] The invention relates to a cross-linked modified polyvinyl alcohol coating solution and a preparation method thereof, which are used for preparing high-barrier and boiling-resistant packaging films. Background technique [0002] The barrier property of a material usually refers to the barrier effect of the material on oxygen and water vapor under the specified temperature and humidity, and the barrier property is one of the important indicators of packaging materials. During the storage of food and medicine, the presence or absence and concentration of oxygen are the key factors affecting their shelf life. In recent years, the demand for high-barrier plastic packaging materials has been increasing. [0003] At present, domestic high-barrier packaging materials mainly include aluminum foil, aluminized film, EVOH five-layer co-extruded film, and PVDC coated film. [0004] Aluminum foil and aluminized film have excellent oxygen barrier and water barrie...

AI Technical Summary

Problems solved by technology

[0004] Aluminum foil and aluminized film have excellent oxygen barrier and water barrier properties, but their disadvantages are that the film is opaque, poor folding resistance, high cost, and difficult to recycle.

The disadvantages of this method are: the viscosity of the modified coating solution is high and unstable, the crosslinking agent is very easy to self-polymerize to form a gel, and the service life is only 2 to 3 hours; and the coating thickness is large and the drying efficiency is low; in addition, due to The free formaldehyde content in the cross-linking agent trimethylol melamine is high, which does not meet the safety guard standard. At present, there is no such commercial cross-linking agent in China

Wang Bo etc. disclosed in the patent application 1687264A, with R (NH 2 ) 2 R (R represents an alkylene or carboxyl group) is used as a condensing agent, and triethylamine or 1,4-oxazepine is selected as a catalyst, and then other auxiliary agents are used to prepare a modified PVA coating solution. It has good barrier properties under state and wet conditions, but the above-mentioned catalysts used in it are all volatile and extremely toxic, which can seriously irritate the human eye and respiratory system and endanger the health of the human body.