Intelligent moisture control film, and preparation method and application thereof

Abstract

The invention belongs to the field of functional films, and relates to an intelligent moisture control film, and a preparation method and application thereof. The intelligent moisture control film comprises a base layer, and an additional layer or additional layers located on one side or both sides of the base layer. The base layer is a porous film with the pore diameter of 0.005-250 micrometers and the porosity of 30-80%, and pores with the pore diameter being one order of magnitude higher or lower than the average pore diameter account for more than 50%. The additional layer/layers is/are adense film or dense films comprising polyvinyl alcohol, a metal salt, and an optional crosslinking agent and/or an optional antibacterial agent. The intelligent moisture control film has an intelligent moisture control function, maintains the humidity of fruits and vegetables when the relative humidity is low, improves the moisture permeability when the relative humidity is high to prevent dewingand rotting of the fruits and vegetables, has oxygen barrier properties, and can be applied to fresh-keeping fruit and vegetable boxes and refrigerators with the fresh-keeping fruit and vegetable boxes.

Description

technical field [0001] The invention belongs to the field of functional films, and more specifically relates to an intelligent moisture control film and its preparation method and application. Background technique [0002] Fruits and vegetables are important foods for human beings, and they are the main sources of basic nutrients (vitamins, minerals, complex carbohydrates, etc.). With the improvement of people's living standards, the requirements for the freshness of fresh fruits and vegetables are getting higher and higher. Fruits and vegetables can continue to carry out life activities such as respiration and transpiration after harvesting, and water loss and nutrient consumption will occur during storage. For every 10°C increase in temperature, the respiratory intensity of fruits and vegetables doubles. The way to keep fruits and vegetables fresh at home is to store fruits and vegetables in the refrigerator to slow down the respiration of fruits and vegetables. In frui...

AI Technical Summary

Problems solved by technology

The temperature-sensitive and moisture-permeable membrane is prone to condensation on the surface of the membrane under high humidity and low temperature; the silicon filter membrane has a moisturizing function, but the moisture permeability cannot be changed with humidity; The performance meets the requirements, but the preparation process is not environmentally friendly, the process is complicated, and there may be problems with excessive chlorine content in the processing process

[0004] CN105986511A discloses the technology of applying natural polymers with good hydrophilic water retention and film-forming properties on base paper with high dry and wet strength, but the cost is relatively high

CN104029449B discloses a coating film with a large moisture permeability, the base layer is an expanded polytetrafluoroethylene film layer, and the coating is a polyurethane emulsion copolymer coating containing hemp stalk core ultrafine powder. Applicable to car lamp housings, but does not have intelligent humidity control performance

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CN103107301A discloses a kind of inorganic coating lithium-ion battery diaphragm, comprises multi-layer structure, is respectively porous flexible base film and the coating that is coated on both sides of base film, coating comprises polyvinyl alcohol and zeolite particle, the auxiliary of this coating The composition does not contain metal salts, and the composite film does not have the function of intelligent moisture control

CN1864829A discloses a hydrophilic-hydrophobic bipolar composite membrane and its preparation method. The membrane has a double-layer structure, the bottom layer is a porous support layer, and the upper layer is a hydrophilic membrane containing lithium chloride. The membrane has high moisture permeability and It has a strong blocking effect on other gas molecules, but it does not have intelligent humidity control

WO2012133805A1 discloses a moisture-permeable membrane, the porous substrate is preferably polytetrafluoroethylene, which is expensive, and the high moisture-permeable performance of the membrane is not good

US20030054155A1 discloses a waterproof and moisture-permeable composite membrane, the hydrophobic layer is polytetrafluoroethylene, and the hydrophilic layer is polyurethane. The membrane has high moisture permeability, but does not have intelligent moisture control performance