JPH051388Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a packaging material for vacuum sealing, and more specifically, when formed into a bag, the inner surface of the bag has good slippage, good opening properties, and easy depressurization. The present invention relates to a packaging material for vacuum sealing that can be heat-sealed, has heat resistance that can withstand boiling in boiling water and heating in a microwave oven, and has excellent properties from the viewpoint of food hygiene because it does not require the use of a dusting agent.

[Prior Art] Recently, vacuum sealing packaging for storing foods and the like by sealing them under reduced pressure is becoming popular in general households, and packaging materials suitable for such packaging are being searched for.

A three-sided seal bag having a heat sealing layer on the inner surface is known as a packaging material for vacuum sealing. After storing the contents in this three-sided sealed bag, the opening is placed over the suction port of the vacuum sealing packaging device, the gas inside the bag is sucked and degassed through the opening, and the sealer of the packaging device is pressed to heat-seal. This allows for sealed packaging.

Here, it is necessary to open the opening when storing the contents in the bag-shaped packaging material or when covering the opening over the suction port, but in the case of no treatment, the heat-sealing layers on the inside of the bag are in close contact with each other. When this happens, opening becomes difficult and work becomes difficult. Therefore, in order to ensure openability, a dusting agent is applied to the inner surface of the bag, that is, the surface of the heat-sealing layer.

Furthermore, if the heat-sealing layer is untreated, when the opening is placed over the suction port and suction is performed, the heat-sealing layers tend to come into close contact with each other, making it difficult to reduce the pressure to the depths of the bag.

[Problems that the invention aims to solve] However, since the dusting agent used to ensure this openness is mainly composed of starch, it tends to become a breeding ground for bacteria, and after the seal is sealed, the bacteria will multiply. There was a problem that sealed storage was not effective.

Additionally, there was a problem in that the original function of sealed storage could not be achieved unless the entire bag was depressurized.

[Means for Solving the Problems] The present invention has been made in view of the above points. That is, according to the present invention, there is provided a packaging material made of a multilayer film having at least a heat-resistant layer and a heat-adhesive layer, wherein the heat-adhesive layer is arranged as the outermost layer on one side of the multilayer film, and the heat-adhesive layer A packaging material for vacuum sealing is provided, the outer surface of which is provided with minute irregularities transferred from a roll having an irregular surface.

As the heat-resistant layer, nylon-6, nylon-
Polyamide resins such as 66 and nylon-610; those having not only excellent heat resistance but also high strength and barrier properties, such as aromatic polyester resins such as polyethylene terephthalate and polybutylene terephthalate, are preferred. Further, it is preferable that these resins have a biaxially oriented film layer because various physical properties such as strength are good.

Biaxially oriented polypropylene films, biaxially oriented polyvinyl alcohol films, and biaxially oriented ethylene-vinyl alcohol copolymer films can also be used as the heat-resistant layer of the present invention, although their physical properties are somewhat inferior to the above-mentioned resins.

For the heat-fusion layer, polyolefin resins such as low-density polyethylene (LDPE), high-density polyethylene (HDPE), linear low-density polyethylene (L-LDPE), and low-crystalline polypropylene; ethylene-vinyl acetate copolymer (EVA); ethylene ionomer (IR), etc. can be used.

Further, it is more preferable that there is a barrier layer in addition to the heat-resistant layer and the heat-adhesive layer. As the barrier layer, vinylidene chloride copolymer resin is most suitable.

In addition, in the packaging material of the present invention, a printed layer may be provided at an appropriate location in addition to the heat-resistant layer and the heat-adhesive layer.

[Example] The layer structure of the packaging material for vacuum sealing of the present invention is exemplified as follows.

Heat-resistant layer/thermal adhesive layer〓 Ny-6/LDPE〓 PET/LDPE〓 OPP/LDPE〓 Heat-resistant layer/barrier layer/thermal adhesive layer〓 Ny-6/PVDC/LDPE〓 PET/PVDC/LDPE〓 OPP/PVDC /LDPE〓 Alternatively, the layer structure may be a heat-resistant layer/barrier layer/printing layer/anchor coat layer/thermal adhesive layer as shown in FIG.

In the above, 〓 means that the surface of the heat-sealing layer has minute irregularities.

As mentioned above, the outer surface of the heat-sealing layer of the packaging material of the present invention is subjected to minute unevenness treatment. Microscopic unevenness refers to unevenness of 1 μm or more in the film thickness direction and plane direction. Light is scattered to some extent and haze increases, but the unevenness does not significantly impair the light transmittance of the film. means. It is desirable that the size of the irregularities be as large as possible without impairing the strength of the film. Such unevenness can be easily obtained by pressing a heated and molten film onto an emboss roll, pine roll, etc. that has unevenness obtained by etching or mechanically processing a mirror-finished roll and transferring the unevenness. can.

The manufacturing method of the packaging material of the present invention is Ny-6/
This will be explained using PVDC/LDPE as an example.

First, an isocyanate-based anchor coating agent is applied to Ny-6 and dried, and then a vinylidene chloride-based copolymer emulsion is applied and dried using an air knife coater to obtain a Ny-6/PVDC laminate.

Next, after corona discharge treatment, an isocyanate-based anchor coating agent is applied and dried on the PVDC surface of the Ny-6/PVDC laminate, and LDPE is laminated using an extrusion lamination method to obtain a layered structure of Ny-6/PVDC/LDPE. . At this time, the roll with the above-mentioned unevenness processing is used to cool and solidify the heated and melted LDPE, and the roll is crimped with a pinch roll.
The uneven surface of the roll is transferred to the LDPE surface. After that, cooled and solidified Ny-6/PVDC/LDPE
The laminate is wound up using a winding device.

The packaging material of the present invention can be made into a three-side sealed bag having an opening 7 as shown in FIG. 2 by sealing the three sides by pressing and heating with the heat-sealing layer on the inside.

Note that FIG. 3 shows a cross-sectional view of the vicinity of the seal portion of the three-sided sealed bag shown in FIG. 2. Note that 8 is a scar group and 9 is a seal portion.

This three-sided sealed bag is subjected to vacuum sealed packaging as follows.

First, the contents are filled from the opening of the three-sided sealed bag. Then, the air is removed from the opening in a sealed packager, and then the opening is heat-sealed. The sealed packaging device has a degassing port and is equipped with a heat sealing mechanism that can be pressed and heated.

In the packaging material of the present invention, the outer surface of the heat-sealing layer is treated with minute irregularities, so the surface with minute irregularities has a small coefficient of friction and becomes slippery, making it difficult to spray dusting agents like in the past. The films can easily slide together without any treatment, and if the textured surface is placed on the inner surface of the bag, the opening can be opened easily.

In addition, when a three-sided sealed bag is used as described above, if suction is applied from one side, if the inner surfaces of the films that make up the bag are smooth and tend to stick together, it will not only be difficult to open, but even if the bag is opened, it will be difficult to open the bag. Because of this, when suction is applied, air remains like bubbles in every corner, making it difficult to remove the air and making the bag ineffective.However, with the packaging material of this invention, the inner surface Good sliding properties allow air to move easily between uneven surfaces.
The bag can be degassed without any air remaining inside the bag.

In addition, since it is easy to open, it is possible to fill the inner part of the bag with contents without contaminating the opening of the bag. If the opening is clean, the opening will be sealed securely, and the inside of the bag will be completely sealed and the inside of the bag will be isolated from the outside. No leakage from the bag.

Furthermore, when the packaging material is rolled up into a roll in the manufacturing process before being formed into a bag, the film can be rolled up neatly without causing problems such as wrinkles because the film has good slippage.

Furthermore, the textured surface scatters light to a certain extent and becomes slightly cloudy, so when it is heat sealed, the heat sealing layer melts in the sealed area and the uneven surface disappears, making it transparent. Since the unsealed area remains cloudy, it has the advantage of being able to determine whether the seal is complete or incomplete.

The packaging material of the present invention is somewhat cloudy due to the textured surface, but since the texture is superficial, the turbidity is such that the contents can be clearly seen. Therefore, seeing through the contents from the outside after vacuum-sealing packaging is not obstructed. In particular, when the contents contain liquid substances, the same principle that allows you to see through ground glass when wet,
You can see through the contents just like a normal transparent film. Furthermore, since the unevenness in the present invention is superficial, it does not collapse during heat sealing and prevents heat fusion, and good heat sealability, which is important for vacuum sealed packaging, is maintained.

Among the packaging materials of this invention, heat-resistant layer/barrier layer/
Thermal adhesive layer allows for heat sealing, and the heat-resistant layer allows the sealed bag to be warmed by placing it in boiling water as a bag, and also has a barrier layer. This blocks oxygen and prevents the contents of the sealed bag from rotting and oxidizing.

In addition, those with the layer structure of heat-resistant layer/barrier layer/thermal adhesive layer have a slightly inferior oxygen barrier property because they do not have the above-mentioned barrier layer, but other characteristics are heat-resistant layer/thermal adhesive layer.
The layer structure is similar to that of the barrier layer/thermal adhesive layer, and by using a resin layer that also has barrier properties, such as polyamide or PET, as the heat-resistant layer, a considerably superior product can be obtained in this respect as well. .

Fig. 3 shows a cross section of a bag near the sealing part when a three-sided sealed bag is formed using only the packaging material of the present invention, but Fig. 4 shows a cross section of the bag with the packaging material of the present invention on one side and the other side. The figure shows a cross section of a bag in which the heat-resistant layer/barrier layer/heat-adhesive layer or the heat-resistant layer/heat-adhesive layer is made into a film with a smooth outer surface of the heat-adhesive layer, and the three ends are heat-sealed. Although this bag has minute irregularities on only one side, it exhibits the same characteristics as a bag that has minute irregularities on both sides.

Experimental example The vinylidene chloride resin-coated side of a biaxially oriented 6-nylon film coated with vinylidene chloride resin is printed, an isocyanate-based anchor coating agent is applied to this printed surface, and the anchor coating agent-coated surface is further coated. Width made of extruded laminated low-density polyethylene and processed with an uneven surface using a pine roll with an uneven depth of 5μ as a cooling roll.
A composite laminate film having the following configuration was obtained at 820 m/m.

Ny-6/PVDC/Printing/AC/LDPE Ny-6/PVDC: [Unitika Co., Ltd. emblem
DCR] AC: Isocyanate anchor coating agent [AD-335A and CAT- manufactured by Toyo Morton Co., Ltd.
100:6 mixture of 100:6...Thickness: 0.5μm] Printing: Layer with printed trademarks, etc. LDPE: Low-density polyethylene [manufactured by Asahi Kasei Corporation, Suntec LDL-2340,
Thickness: 25 μm] The laminated packaging material was rolled up into a roll without using a dusting agent, and it was very easy to roll up without any wrinkles.

Furthermore, since no dusting agent was used, the adhesion and proliferation of general living bacteria could be ignored, making it a very preferable packaging material from the viewpoint of food hygiene.

Using the vacuum sealing packaging material described above, a packaging bag was made using a three-sided seal bag making machine.

During bag making, when the film fed out from the paper feeder is folded in half, a group of penetration scars is created around the vertically fused portion of the bag and the edge line of the bag.
Then heat fused to a width (width) of 200mm and a length (vertical).
Manufactured a 300mm three-sided sealed bag.

The bag has two sides, so the puncture site for the scar group is a double layer of film folded in half (820mm x 1/2, 410mm wide).
One end of the scar, a part that was 200 mm inward from that end, and a part that was 10 mm inward from the other end (10 mm outside the scar group was cut and removed).

The obtained bag is divided into two parts in the vertical direction as shown in Figure 2.
The sides and one horizontal side are fused, one upper side is open, and a scar group 8 with a width of about 2 mm is continuous along the edge line of the fused part on the two vertical sides. The scars were all sealed with a heat-adhesive layer. This three-sided sealed bag had a smooth inner surface and was very easy to open.

The cooked food was stored through the opening of this three-sided sealed bag, and then the opening was heat-sealed after degassing from the opening using a sealed packaging device. Deaeration was performed well from every corner. The heat-adhesive layer melted in the sealed area and became transparent, confirming that the seal was reliably sealed. This package could be heated by immersing it in hot water, had good barrier properties, and could preserve its contents for a long period of time without spoilage or oxidation.

Furthermore, since the bag had scar groups on both edges, it was possible to easily open the bag from both sides using just the force of the fingers.

The packaging material obtained in this experimental example and the bag obtained using this packaging material had the following advantages in addition to the above-mentioned characteristics.

It is extremely hard and sturdy, making it easy to handle.

The bag is strong and will not break or leak even when internal pressure is high.

It has excellent cold resistance and can be stored in the refrigerator, ice-cold/partial freezing, or frozen freezer without any problems.

The outer side when made into a bag has good printability and does not leave any printing ink odor. In addition, the contents can be displayed using a ballpoint pen, magic ink, etc.

Physical properties do not change much even over a long period of time.

[Effects of the invention] As mentioned above, in the packaging material for vacuum sealing of the present invention, the outer surface of the heat-sealing layer is treated with minute irregularities, so this finely uneven treated surface becomes extremely slippery. , the film can easily slide onto each other without applying a dusting agent as in the past, without causing wrinkles during packaging material manufacturing, and when the textured surface is placed on the inner surface of the bag. This makes opening the bag easier. In addition, by not using a dusting agent, the adhesion of general viable bacteria can be avoided.
Breeding is almost eliminated, making it very desirable in terms of food hygiene.

In addition, when a three-sided sealed bag is used and suction is applied from one side, the inner surface of the packaging material slides well and the air can easily move between the uneven surfaces, allowing air to evacuate without remaining inside the bag. be able to.

Furthermore, since it is easy to open when it is made into a bag, it is possible to fill the contents into the inner part of the bag without contaminating the opening of the bag. If the opening is clean, the seal at the opening will be reliable, the seal will be completely sealed, and the inside of the bag will be isolated from the outside, preventing germs from entering the bag, and the contents of the bag will be completely sealed. No leakage occurs.

Furthermore, the textured surface scatters light to a certain extent and becomes slightly cloudy, so when it is heat sealed, the heat sealing layer melts in the sealed area and the uneven surface disappears, making it transparent. Since the unsealed area remains cloudy, it is possible to determine whether the seal is complete or incomplete.

Furthermore, since the heat-resistant layer is present, the bag can withstand boiling in boiling water and heating in a microwave oven.

[Brief explanation of the drawing]

Fig. 1 is a schematic cross-sectional view showing one embodiment of the packaging material of the present invention, Fig. 2 is a schematic perspective view of a three-sided seal bag made using the packaging material of the present invention, and Fig. 3 is a schematic cross-sectional view showing an embodiment of the packaging material of the present invention. Figure 4, a cross-sectional view of the vicinity of the sealing part of a three-sided seal bag, was created using the packaging material of the present invention that has minute irregularities on one side and a film with a smooth outer surface of the heat-adhesive layer on the other side. FIG. 3 is a cross-sectional view of the vicinity of the seal portion of the three-sided sealed bag. 1... Heat resistant layer, 2... Barrier layer, 3... Printing layer, 4... Anchor coat layer, 5... Heat fusion layer,
6...Minute unevenness, 7...Opening, 8...Scar group, 9...Seal portion.

Claims (1)

[Scope of utility model registration request] A packaging material made of a multilayer film having at least a heat-resistant layer and a heat-adhesive layer, the heat-adhesive layer being arranged as the outermost layer on one side of the multilayer film, and the outer surface of the heat-adhesive layer having an uneven surface. A packaging material for vacuum sealing, characterized in that it is provided with minute irregularities transferred from a roll.