JPH0516294U - Heat-sealed lid material - Google Patents

Abstract

(57) [Summary] [Purpose] A lid material used for aseptic specification plastic containers for chemicals, foods and drinks, etc. by an automatic packaging machine, without sticking and accumulating on the cutting edge during high speed press punching.
Easy peel heat-sealing lid material that does not curl even in high-temperature processing, does not easily generate pinholes, and has excellent adhesion. [Structure] Aluminum foil with a thickness of 50 μm or less / 10
˜50 μm intermediate layer / 0.5 to 15 g / m ² thick E
Heat-sealing lid material consisting of VOH layer.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 INDUSTRIAL APPLICABILITY The present invention may be used for aseptic plastic containers (including polyethylene-coated paper containers), polystyrene containers or polypropylene containers such as pharmaceuticals, small medical supplements, biotechnology chemicals, supplements or foods. It relates to an easy peel lid material which is particularly good for the wide-mouth container used.

[0002]

[Prior Art]

 With the recent development of product packaging technology, various chemicals, supplements or foods and drinks have been packaged in containers made of synthetic resin. In this case, there is a need not only for inexpensive sealing and for the container not only to be hermetically sealed but also to be easily opened at the time of use. Therefore, it is necessary to hold a wide-mouthed container with highly viscous chemicals, foods, or shapes. It is widely adopted to put equipment and the like, and use an automatic wrapping machine to wrap with a lid material mainly made of aluminum foil.

In the conventional automatic packaging, a hot-melt type lid material is used as a sealant from the viewpoint of cost and speed, but even in the food and drink field, hygienic aseptic packaging can be performed. It is gradually spreading, and it is expected that it will become a packaging machine mainly for aseptic specifications in the food and beverage industry from the aspect of taste in the future.

This aseptic packaging machine mainly sterilizes the container body and lid material using an aqueous solution of hydrogen peroxide, and then treats it with hot air at 200 to 300 ° C. to completely decompose and dry the hydrogen peroxide. However, in the case where aluminum foil is directly laminated with hot melt like the conventional lid material, there was a problem that the hot melt was melted or the lid material was deformed during this hot air treatment. ..

In such a high-temperature treatment, when an ethylene-vinyl acetate copolymer system or a polyethylene-based sealant film, which has been mainly used in the past, is used, the lid material curls and the film cross section is fluffed during cutting. They may stand up and become unusable as a lid material for automatic packaging machines.

Therefore, in order to solve this problem, the resin layer was thinned to directly coat the aluminum foil with an adhesive resin for the purpose of preventing curling, but the problem of curling could be solved for the time being. The problem of sticking and accumulating on the cutting edge during high-speed press punching with a high-speed heat-sealing machine cannot be solved at all, and a serious problem remains. In addition, since the resin layer is thin, pinholes are likely to occur, the aluminum foil comes into contact with the contents through these pinholes, and other problems such as poor content resistance to acidic contents are also included. is doing.

[0007]

[Problems to be solved by the device]

 Even when used in an aseptic type packaging machine, the present invention has an aseptic type in which sticking and accumulation on the cutting edge during high-speed press punching, fluffing of the film cross section during curling and cutting, and pinholes do not easily occur. The purpose is to develop a heat seal lid material.

[0008]

[Means for Solving the Problems]

According to the present invention, an intermediate layer having a thickness of 10 to 50 μm and containing polyethylene or ethylene copolymer resin as a main component is provided on one side of an aluminum foil having a thickness of at least 50 μm, and a thickness of 0.5 to 15 g / A heat-sealing lid material, characterized in that a saponified material layer for the ethylene-vinyl acetate copolymer part of m ² is provided.

Most of the aluminum foil for the heat-sealing lid material is covered with printing or a corrosion resistant coat on the surface of the packaging body, but there are some without this. Even if there is no, the effect can be used without change.

As the lid material, aluminum foil is used for punching the lid material and for maintaining the shape during hydrogen peroxide sterilization and during drying, but it is sufficient if it has rigidity, a gas barrier property, and a light shielding property according to the application. The aluminum foil is usually 50 μm or less, preferably 20 to 40 μm in thickness in terms of cost and flexibility.

The intermediate layer is not particularly limited, but it is necessary to have good adhesiveness with the resin of the heat sealing layer. Therefore, polyethylene or ethylene copolymer resin, particularly low density polyethylene, ethylene-vinyl acetate copolymer is used. Is preferred. In order to improve the adhesion between the aluminum foil and the intermediate layer, it is preferable to use an anchor coating agent on the aluminum foil.

The thickness of the intermediate layer at this time is not limited, but in many cases there are steps or irregularities for the joint part of the mold at the mouth of the container to be sealed, and consideration should be given to overcoming this. It is preferable that the thickness is about 10 to 50 μm. It is possible to overcome this by increasing the thickness of the intermediate layer when the irregularities at the mouth of the container are large, but as a general rule, it is rare that a thickness exceeding 50 μm is required, so there is no merit to further increase the thickness. In terms of cost, 50 μm is sufficient.

It is preferable to use a saponified ethylene-vinyl acetate copolymer (hereinafter referred to as heat sealing agent) layer having a melt index of 5 to 50 g / 10 minutes and a Vicat softening point of 30 to 60 ° C. .. A heat-sealing agent having a melt index of less than 5 g / 10 minutes becomes difficult to dissolve in an organic solvent, and it becomes difficult to roll-coat the heat-sealing agent to the aluminum foil / interlayer laminate. On the other hand, if the melt index exceeds 50 g / 10 minutes, the heat-sealing agent coated on the aluminum foil / intermediate layer has high tackiness, which makes it difficult to wind and unwind after coating.

When the Vicat softening point is lower than 30 ° C., the heat resistance required in the aseptic system is insufficient, the resin becomes sticky, and blocking easily occurs. On the other hand, if the Vicat softening point exceeds 60 ° C, it is necessary to set the heat sealing temperature high, which makes it difficult to apply to a high-speed automatic packaging system. In particular, when a heat-sealing agent having a melt index of more than 50 g / 10 minutes and a Vicat softening point of less than 30 ° C. is used, the hot tack property on the low temperature side becomes poor, while the melt index is less than 5 g / 10 minutes and the Vicat softening With a heat-sealing agent having a point of more than 60 ° C, the hot tack property on the high temperature side deteriorates, the sealing workability deteriorates, and the productivity decreases.

A method of dissolving the heat-sealing agent in an organic solvent and coating it on the intermediate layer is used for coating, but in some cases, it may be prepared by melt extrusion coating on the intermediate layer. At this time, the thickness is 0.5 to 15 g / m ² . If the thickness is less than 0.5 g / m ² , there will be a problem in the uniformity of coating amount, and there is a risk of defects that are not coated at all. On the other hand, when the thickness is 15 g / m ² or more, the effect is saturated and there is no need to apply more.

The adhesive layer of the present invention does not stick even when melted in hot air treatment, causes curling of the lid material, and does not have a fluff in the case of cutting. Has a sufficient adhesive strength, and in the case of peeling, it is adjusted so that it can be peeled easily by hand. Of course, it is necessary that heat sealing is possible when adhering.

The aseptic heat-sealing lid material of the present invention does not cause sticking and accumulation on the cutting edge due to press punching even at high temperature and for a long time, and there is no fluffing of the cross section during curling and cutting, and It is a lid material that does not easily generate pinholes and therefore has few troubles even when placed on an automatic packaging machine.

[0018]

[Action]

The heat-sealing lid material of the present invention comprises at least an aluminum foil / intermediate layer / heat-sealing agent layer, the aluminum foil having a thickness of up to 50 μm, and the intermediate layer having a thickness of 10 to 50 μm made of polyethylene or ethylene copolymer. This is a product in which a partially saponified ethylene-vinyl acetate copolymer as a heat sealing agent layer is laminated to a thickness of 0.5 to 15 g / m ² as a heat sealing agent layer. Heat-sealing by an automatic packaging machine-There is no fluffing of the cross section even if punching is performed, there is no accumulation of section powder on the cutting edge, it has an appropriate hot tack property, and curling of the lid material etc. does not occur easily. ing.

Of course, it is free to print on the cover material of the present invention and to provide a protective layer for this printing surface, etc. within the scope of the present invention, within the scope of the present invention.

[0020]

【Example】

An anchor coat layer of a titanium coupling agent was provided on the opposite surface of the corrosion-resistant aluminum foil (35 μm), and then polyethylene was extrusion-coated to a thickness of 20 μm. Furthermore, a partial hydrolyzate of ethylene-vinyl acetate (MI: 12 g / 10 min, Vicat softening point: 45 [deg.] C. (solid content: 10% -toluene solution)) was applied by a roll coating method to a solid content of 3 g / m < ² >. .

When the lid material was used for jam packaging in an aseptic packaging line as a lid material for a container made of polyethylene-coated paper, the sealing property was perfect and the line suitability was very good as compared with the conventional hot melt construction. It was satisfactory.

On the other hand, for comparison, when a lid material obtained by directly coating an aluminum foil with a low-density polyethylene hot melt was flown through an aseptic packaging line, hydrogen peroxide was decomposed and the high temperature in the drying step (130 ° C.) Blocking occurred. In addition, tunneling occurred in the next jam (75 ° C) filling process and sealing, which caused a problem in sealing performance.

[0023]

[Effect of the device]

 As can be seen from the above description, the present invention is an invention relating to an aluminum lid material suitable for an automatic aseptic packaging machine.With the configuration of the present invention, when the lid material is punched at a high speed, the cross section of the film is fluffed. It is intended to provide a heat-sealing lid material which has no accumulation of chips on the cutting edge, does not curl even at high temperatures, can be subjected to high-temperature hot-air treatment, and has a suitable hot tack property.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a laminated body of a heat-sealing lid material according to the present invention.

[Explanation of symbols]

 1 Corrosion resistant coat 2 Printing 3 Aluminum foil 4 Intermediate layer 5 Heat sealing agent layer

Claims (3)

[Scope of utility model registration request] 1. An intermediate layer comprising a polyethylene or ethylene copolymer resin having a thickness of 10 to 50 μm as a main component is provided on one surface of an aluminum foil having a thickness of at least 50 μm, and the surface has a thickness of 0.5 to 15 g. / M ² of ethylene-
A heat-sealing lid material, which is provided with a partially saponified vinyl acetate copolymer layer. 2. The melt index is 5 to 50 g / 10.
The heat-sealing lid material according to claim 1, wherein a partially saponified ethylene-vinyl acetate copolymer having a Vicat softening point of 30 to 60 ° C is used. 3. The heat-sealing lid material according to claim 1, wherein the partially saponified ethylene-vinyl acetate copolymer layer is provided by a roll coating method.