PET anti-fog easy-to-uncover film and manufacturing method thereof

Abstract

The invention provides a PET anti-fog easy-to-uncover film. The PET anti-fog easy-to-uncover film comprises a PET base layer and an anti-fog heat-sealing layer coated on the surface of the PET base layer, the anti-fog heat sealing layer is prepared from the following raw materials in percentage by weight: 10 to 12% of acrylate modified polyurethane prepolymer, 3 to 4% of dimethylolpropionic acid, 1.5 to 3.5% of 3-allyloxy-2-hydroxy-1-propanesulfonic acid sodium salt, 1.2 to 2.5% of maleic anhydride, 3 to 5% of isopropanol, 3 to 5% of ethylene glycol, 0.1 to 1.0% of an initiator, 0.2 to 1.2% of a catalyst, 0.3 to 0.5% of a defoaming agent, 0.1 to 0.3% of a pH regulator, 0.2 to 1.0% of precipitated silica, 0.5 to 1.2% of palm wax anti-sticking agent and 65 to 75% of soft water; and the PET anti-fog easy-to-uncover film provided by the invention has good heat sealing strength with a PET box and good cold and hot anti-fog effects.

Description

technical field [0001] The invention relates to the technical field of food packaging, in particular to a PET anti-fog and easy-to-release film and a manufacturing method thereof. Background technique [0002] At present, the high-quality packaging boxes used in fresh food packaging on the market require high transparency, easy-to-open lids, hot and cold anti-fog functions, etc., so PET films are used to heat seal PET transparent boxes. However, since the PET film and the PET box are not easy to be heat-sealed and bonded, and they need to have cold and heat anti-fog functions after bonding, this has caused many technical obstacles to product development and application. [0003] Traditionally used in the packaging and sealing of fresh food boxes in China, the sealing is achieved by coating or compounding the surface of the film and then heat sealing with the PET box. However, the lamination method has the following disadvantages: 1) It is difficult to remove the film. Becau...

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Problems solved by technology

However, the lamination method has the following disadvantages: 1) It is difficult to remove the film. Because the thickness of the lamination film is relatively thick, generally 20-70 μm, and the thickness is uneven, it is easy to cause the heat seal to be too large during use, which is not easy to uncover, and the thickness of the lamination film Unevenness leads to large fluctuations in heat seal strength, and it is easy to tear the cover film; 2) The base material of the lamination film is paper, so the transparency is poor or completely opaque; 3) It does not meet the same material requirements that environmental protection needs to meet, Generally, the boxes used to hold fresh fruits are made of PET, but the base material used for the coating is paper, the material of the coating is PP, and the composite film is PE or CPP, so it does not meet the requirements of environmental protection and uniform material recycling. Requirements; 4) It is difficult to meet the anti-fog requirements. The current fresh packaging box is in the process of alternating cold and hot, and the heat-sealing film will be fogged, which will affect the transparent and visible use experience of the packaging box.

[0004] At present, there are two main methods for anti-fogging of fresh food boxes: one is to directly add anti-fogging agent to the heat-sealing coating. Poor effect, not up to requirements

The second is to achieve the easy-to-remove anti-fog effect by first coating the heat-sealed emulsion and then coating the anti-fogging agent, but the adhesion of the coated coating and the anti-fogging agent is poor and the anti-fogging agent is isolated during heat sealing effect, resulting in low heat-sealing strength, which cannot meet the sealing strength

This method has the following disadvantages: the thickness of the composite PE or CPP film is thick, the transparency is low, and the cost increases, and PE or CPP and PET do not belong to the same material, which does not meet the environmental protection requirements of recycling the same material

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