KR20020084326A - A layer plastic film for package of food-receptacle maintainning excellent adhesive strength by heat and anti-stain - Google Patents

Abstract

PURPOSE: A laminated film for the package of a food container is provided to improve a heat adhesive property thereof and prevent the generation of stain or spots thereon caused during the food container receives hot food after the sealing of the container. CONSTITUTION: The film for the package of food container, expressing a good heat adhesive property and an anti-stain function, is formed by laminating a thin polyester film(1) of 12-25micrometers thick, a thin polyethylene film(2) of 20-30micrometers, and a mixed film(3) of 5-15micrometers, formed by mixing a hot melt resin and polyethylene resin at a certain ratio, and forming a corona discharge processed layer(4) on the surface of the mixed film.

Description

LAYER PLASTIC FILM FOR PACKAGE OF FOOD-RECEPTACLE MAINTAINNING EXCELLENT ADHESIVE STRENGTH BY HEAT AND ANTI-STAIN}

The present invention relates to a laminated film having excellent heat adhesiveness and stain prevention function used for food container inlet packaging of a synthetic resin material. More specifically, excellent heat used for sealing a food container of a synthetic resin material packed with hot food contents. Laminated film with adhesive and anti-staining function. The upper layer is made of polyester film, the middle layer is made of PE film, and the lower layer is made of mixed film (adhesive film) composed of hot melt resin and PE resin, and the corona discharge-treated food container on the surface of the adhesive film. Regarding the laminated film for packaging, polypropylene, polystyrene, ABS, PVC, etc. have been used as a synthetic resin material used as a food container in a synthetic resin food container or a film packaging field.

PVC was used in the early days of using synthetic resin containers, but in the process of forming PVC containers, additives such as fillers, plastics, and stabilizers are added, so toxic substances are leached or eluted. Polystyrene is not suitable for food containers where the contents of food containers are processed and packaged at high temperatures because they have a high specific gravity (1.04-1.1), low heat deflection temperature and start to soften at 70 ℃. It is used as a packaging container.

In addition, polypurpyrene is a container that is packed with high-temperature food contents in the food processing process because of its excellent heat resistance, tensile strength and burst strength.

In addition, a laminated film is mainly used as a film that seals the periphery of the inlet of the polypuroprene container containing the high temperature food contents as described above, and a polystyrene film is laminated on a polyester film having excellent tensile strength and bursting strength. There is a film subjected to corona discharge treatment on the ethylene surface, and a film obtained by laminating a polyester film, a poly ethylene film and a hot melt film is laminated.

However, even though the laminated film obtained by laminating poly ethylene on polyester and the surface of corona discharge is improved in adhesion by corona discharge treatment, the original poly ethylene is hard to be dissolved in solvent and expands into solvent because it is a crystalline plastic and stable resin. It doesn't stick.

Therefore, even after pretreatment such as steam, thermal electronic treatment (corona discharge), etc. to activate the surface, it is difficult to obtain good adhesiveness, and in particular, excellent thermal adhesion with a container of a poorly adherent material such as polyfuropyrene. Because of the difficulty, poor adhesion occurs and even after packing, problems such as leaching of the contents.

In addition, the laminated film obtained by laminating polyester film, poly ethylene film and hot melt film and corona discharged the surface of hot melt has excellent adhesiveness with polypuropyrene container due to its excellent heat adhesiveness. Used.

However, problems arise in packaging containers containing hot food.

This is because steam is generated from the hot contents in the polypuroprene container after packaging by thermal bonding, and atomization occurs, and fine atomized particles adhere to the corona discharge-treated hot melt film surface, and they accumulate to form droplets (water droplets). The heat capacity is increased to melt the uneven surface due to the corona discharge of the hot melt film surface, and the melted portion becomes smooth as the interfacial tension becomes transparent.

Originally, corona discharge is applied to the hot melt film, so that an uneven number of irregularities are formed so that the entire laminated film becomes translucent so that the contents in the polypuroprene container are invisible and invisible.

However, the above phenomenon remains transparent on the part where water droplets are attached to the whole surface and translucent part on the other part, so that stains naturally occur, and thus the value as a packaged product decreases.

The present invention provides a film which does not cause staining on the packaging film due to the phenomenon of heat adhesiveness which wraps the inlet of the polypuropyrene container or the resin container containing the hot contents and the hot contents after the packaging. For the purpose of

As a means for achieving the above object, the film is excellent in adhesion with the inlet (peripheral part) of the polypuroprene container but is not melted at the water droplet temperature of water vapor generated from the contents in the polypuropyrene container. It is to provide a laminated film for packaging a synthetic resin food container having excellent heat adhesion and stain prevention function by laminating a film having a high melting point by mixing in an appropriate ratio to the adhesive layer.

1-partial cross-sectional view of the present invention

With the development of instant food, the quality of packaging technology is increasing with the increasing demand for synthetic resin containers and film packaging.

For example, jams, ramen, pumpkin porridge, pine nuts, sesame porridge, ham rice, fish cakes and even oden are developed as instant foods, and excellent packaging and film packaging are of course improved.

As a part of the above food packaging technology improvement, the present invention has excellent adhesiveness with polypuropyrene food containers and other synthetic resin containers containing hot contents, especially in the food processing process, and staining or deterioration occurs in packaging films after packaging. It relates to a laminated film for packaging a synthetic resin container not specifically described as described in detail 1, the PE film (2) having a thickness of 20-30㎛ laminated on a polyester film (12) having a thickness of 12-25㎛ 1 hot melt resin And a mixed film (adhesive film) 2 having a thickness of 5-15 μm obtained from a synthetic resin in which a predetermined amount of polyethylene resin is blended, and a laminated film (A) having a corona discharge-treated layer (4). .

The hot melt resin is ethylene vinyl acetate copolymer (EVA resin), ethylene acrylic copolymer copolymer (EEA resin), ethylene methyl acrylate (EMA resin), EAA resin and the like.

Due to the heat deformation characteristics of such a resin,

Softening point of EVA resin is VICAT softening point temperature is 47-69 ℃, EEA resin polymerization is different in the softening point depending on the amount of ethyl acrylate added, but generally belongs to the temperature range of EVA softening point.

In addition, it is known that the softening point of polyethylene is in the range of 120 ° C to 130 ° C.

As mentioned above, hot melt resin has extremely excellent thermal adhesiveness but low melting point, and polyethylene has poor thermal adhesiveness but high melting point is used to mix the resin at an appropriate ratio to obtain sufficient thermal adhesiveness and high melting point. Can be obtained.

Their blending ratio is 20-50wt% of hot melt resin, 80-5Owt% of polyethylene (low density polyethylene), and in this mixing range, melting point of 95% or more can be obtained with excellent adhesion.

When the amount of hot melt resin is increased above the above range, the melting point of the mixed film falls below 95 ° C., and when the amount of hot melt resin is 20% or less, the adhesion is inferior.

The reason why the melting point of the mixed film is set to 95 ° C is generally because the food is automatically packed in a container in which food is increased or cut in the food processing process, and thus the temperature of the content does not become 95 ° C or higher.

Looking at the action of the laminated film prepared in the above manner, in particular the mixed film having an adhesive force, first of all contains a significant amount (20% or more) of hot melt resin excellent in heat adhesiveness, and also has a corona discharge treatment to ensure sufficient thermal adhesion In the anti-staining action, the melting point of the mixed film obtained by mixing the hot melt resin and poly ethylene is not lower than 95 ℃, and the temperature of the food in the packaging does not rise above 95 ℃. Even when attached to the film, the unevenness formed by the corona discharge in the mixed film is maintained without being melted, so that the film is not stained and remains translucent so that the contents are not visible.

According to the present invention, the laminated film for packaging a food container is laminated with a film obtained by mixing a hot melt resin having excellent thermal adhesion and a mixed resin of polyethylene having a high melting point, and thus has excellent thermal adhesiveness as well as hot packaging container contents after packaging. It can be said to be a laminated film for packing food containers that can be greatly spotlighted in terms of functionality and economics as it can greatly increase the value of the product by excellent packaging and prevent expensive stains and deterioration.

Claims (2)

It is excellent in that corona discharge treatment is carried out on the surface of mixed resin film, which is an adhesive layer, by laminating each thin film in the order of mixed resin film, which is a mixture of polyester film, polyethylene resin, hot melt resin and polyethylene resin Laminated film for packing food containers with heat adhesiveness and stain resistance. The laminated film for packaging food containers according to claim 1, wherein the mixed film is a mixed film mixed at a ratio of 20-50 wt% of hot melt resin and 80-50 wt% of polyethylene resin.