JP6778544B2 - A method for manufacturing a film for an opening piece, an opening piece, a base material film for a packaging body, a packaging body having an opening piece, and a film for an opening piece. - Google Patents

Description

The present invention relates to an opening piece, for example, for opening a package that seals the contents of processed food such as sausage and processed cheese, and a package having the opening piece.

The packaging of processed foods such as sausages and processed cheese is usually formed into a cylinder by a packaging film, the inside of which is filled with processed foods, and both ends of the cylinder in the longitudinal direction are sealed with aluminum wire clips or the like. It has a structure.
In this type of packaging, it is necessary to peel off the packaging film to expose the processed food as the content, and for this purpose, some packages are provided with an opening piece called a cut tape or an opener.

It is known that the opened piece is composed of a vinylidene chloride-based resin composition having a composition similar to that of the packaging film, but the opened piece shrinks due to the retort heat treatment when sterilizing the processed food package, and the opened piece is rolled up. This created an unfavorable situation for ensuring food safety.
In order to solve this problem, an opened piece made of a laminate of resin compositions having different heat shrinkage rates has been proposed (Patent Document 1).

Real Fairness 08-280 Gazette

However, since the conventional film aims at the improvement effect on the premise that curl is generated due to heat shrinkage in the cylindrical package, the effect varies greatly, and in some cases, the curl generated causes the adhesion to the package. Since it has deteriorated, further improvement is required.

The present invention has been made in view of the above problems, and an object of the present invention is a film for an opening piece having excellent adhesion even in a cylindrical package, an opening piece formed from the film, and a package provided with the opening piece. It is an object of the present invention to provide a base material film for a body, a package using the base material film for a packaging body, and a method for producing a film for an opening piece.

The present inventors have found that the problem can be solved by the following.
1. 1. A package made of a vinylidene chloride-based resin composition and having an opening piece having a two-layer structure, and the winding height when welded at a position 6 mm from the winding end of the opened piece is less than 1 mm. A packaging body characterized by that.
2. A film for an opening piece for forming an opening piece, wherein the curl amount when cooled at 23 ° C. for 2 hours after being heat-treated at 120 ° C. for 30 minutes is 7 mm or less.
3. 3. An opening piece formed from the opening piece film.
4. In the base film for a packaging body provided with an opening piece, the opening piece becomes concave when the opening piece film for forming the opening piece is heat-treated at 120 ° C. for 30 minutes and then cooled at 23 ° C. for 2 hours. A base film for a packaging body, which is provided on a base material film for a packaging body in terms of surface.
5. A packaging body using the base material film for the packaging body.
6. A method for producing a film for an opening piece containing a vinylidene chloride-based resin, which comprises at least the following steps in order.
1. 1. Step of melt extrusion of vinylidene chloride resin composition 2. 2. Step of relaxing the melt-extruded composition into a film by stretching. 7. Step of re-relaxing the relaxed film with a heating roll. The method for producing a film for an opening piece according to the above 6, wherein the re-relaxation rate by the heating roll relaxation step is 0.5 to 20% in the MD direction and 0.5 to 40% in the TD direction.

According to the present invention, a film for an opening piece having excellent adhesion, an opening piece formed from the opening piece, a base material film for a packaging body having the opening piece, a packaging body using the base material film for the packaging body, and an opening piece. A method for producing a film for use can be provided.

Schematic diagram showing the curl height Illustration of the package in which the opened piece is welded Detailed view of the opened piece

The package of the present invention is a package having an opened piece having a two-layer structure made of a vinylidene chloride-based resin composition, and is rolled when a position 6 mm from the rolled end of the opened piece is welded. It is characterized in that the height is less than 1 mm.

The opening piece of the present invention is formed by cutting a film for opening piece into a desired size. The film for an opening piece of the present invention comprises a vinylidene chloride-based resin composition.
<Vinylidene chloride resin composition>
The vinylidene chloride-based resin composition contains vinylidene chloride-based resin as a main component. Here, the main component means that the vinylidene chloride resin is contained in an amount of 50% or more. The vinylidene chloride-based resin contains a vinylidene chloride copolymer as a main component. The vinylidene chloride copolymer is a copolymer formed from 60 to 98% by weight of vinylidene chloride and at least 2 to 40% by weight of a monomer copolymerizable with vinylidene chloride, and is a vinylidene chloride monomer (monomer). ) And a monomer copolymerizable with vinylidene chloride are suspension-polymerized or emulsified-polymerized.

Examples of the monomer copolymerizable with vinylidene chloride (hereinafter referred to as comonomer) include vinyl chloride, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, lauryl acrylate and stearyl acrylate. Acrylic acid alkyl esters such as (1-18 carbon atoms of alkyl group); methacrylic acid alkyl esters such as methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, lauryl methacrylate and stearyl methacrylate (alkyl group carbon number). 1-18); Vinyl cyanide such as acrylonitrile and methacrylic acid; Aromatic vinyl such as styrene; Vinyl ester of aliphatic carboxylic acid having 1 to 18 carbon atoms such as vinyl acetate; Alkyl vinyl ether having 1 to 18 carbon atoms; Vinyl polymerizable unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and itaconic acid; alkyl esters of vinyl polymerizable unsaturated carboxylic acids such as maleic acid, fumaric acid and itaconic acid (including partial esters. The number of carbon atoms of the alkyl group is 1 to 18); other examples include diene-based monomers, functional group-containing monomers, and polyfunctional monomers.

These comonomers can be used alone or in combination of two or more. Among the comonomers, vinyl chloride, methyl acrylate or butyl acrylate is preferable, and vinyl chloride is more preferable. Therefore, a more preferred vinylidene chloride copolymer is a vinylidene chloride-vinyl chloride copolymer. The content ratio of vinylidene chloride in the vinylidene chloride copolymer is preferably 70% by weight or more, more preferably 80% by weight or more. The upper limit of the content ratio of vinylidene chloride is not particularly limited, but from the viewpoint of extrusion processability and the like, it is usually 98% by weight, and in most cases 95% by weight.

The reducing viscosity of the vinylidene chloride resin is preferably in the range of 0.035 to 0.070, more preferably in the range of 0.040 to 0.065, and in the range of 0.045 to 0.063. It is more preferable to have. If the reducing viscosity is too small, the extrudability of the film into a molded product is insufficient, and if it is too large, it may have a tendency to be colored or melt molding may be difficult.

[Additive]
The vinylidene chloride-based resin can further contain various additives. As the additive, either an organic substance (may be a polymer) or an inorganic substance can be used. Examples of the additive include a plasticizer, a surfactant, a lubricant and the like.
(Plasticizer)
Examples of the plasticizer include dioctyl phthalate, tributyl acetylcitrate, dibutyl sebacate, dioctyl sebacate, acetylated monoglyceride, acetylated diglyceride and acetylated triglyceride.
(Surfactant)
Examples of the surfactant include nonionic surfactants such as glycerin fatty acid ester, polyglycerin fatty acid ester, sorbitan fatty acid ester and polyoxyethylene sorbitan fatty acid ester.
(Glidant)
Examples of the lubricant include inorganic lubricants such as silicon dioxide, zeolite and calcium carbonate, organic lubricants and the like, and these can be used in combination.
Examples of the organic lubricant include saturated fatty acid amides, unsaturated fatty acid amides, substituted amides and thioether compounds.

When the additive is a liquid additive such as a plasticizer, the content of the additive is preferably in the range of 0.05 to 10 parts by weight with respect to 100 parts by weight of the vinylidene chloride resin, and is 0. It is more preferably in the range of .5 to 8.0 parts by weight, and even more preferably in the range of 1.0 to 6.0 parts by weight. In particular, if the upper limit of the blending ratio of the liquid additive is within the above range, stickiness due to bleed-out can be suppressed. When the additive is a powder additive such as a surfactant and a lubricant, the range is preferably 0.1 to 10 parts by weight, preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the vinylidene chloride resin. It is more preferably in the range of 8.0 parts by weight, further preferably in the range of 1.0 to 6.0 parts by weight.

<Two-layer structure opening piece>
The film for opening pieces for forming the opening piece of the present invention can be produced by a molding method such as a melt extrusion method, a solution casting method and a calender method, but the melt extrusion method is preferable in terms of production efficiency. Examples of the melt extrusion method include a T-die method and an inflation method, and the inflation method is preferable from the viewpoint of adhesion. It is possible to wind up one layer at a time and then stack the layers, but it is preferable to form a two-layer structure by biaxially stretching the layers by the inflation method and then stacking the two layers as they are.

The thickness of each of the two layers is not particularly limited and may be the same or different, but it is preferable that each layer is 20 to 60 μm and the two layers are 40 to 120 μm from the viewpoint of openability.

In the present invention, a normal inflation biaxial stretching method can be adopted.

<The rolled height of the opened piece is less than 1 mm>
The present invention is characterized in that, when the opened piece provided in the package filled with food or the like is welded at a position 6 mm from the rolled end, the rolled height from the package is less than 1 mm. By doing so, it is possible to suppress the occurrence of curling of the opened piece and reduce accidents in the package without deteriorating the openability of the package.

The opened piece of the present invention is welded to the package by a method such as ultrasonic waves, and when one end thereof is supported and peeled off, the welded portion with the package is destroyed and the package is opened. The curl height of the present invention is an evaluation of the curl height of one end to be supported, and the end to be supported and peeled off is the rolled end of the present invention, and the opposite end is the other end.

The welding position in the present invention is based on a position 6 mm closer to the other end from the winding end, and the other end may be welded to such an extent that it does not interfere with the measurement of the winding height. FIG. 2 shows a package welded at a position preferable to the present invention. FIG. 3 shows the most preferable welding position for measuring the curl height. In FIG. 3, 1, 2 and 3 are welding sites, which are the first joint, the second joint, and the third joint, respectively. The unit of the number indicating the size in the figure is millimeter.

The first joint portion 1 is a joint portion that serves as a starting point for tearing the packaging film in a planar shape when the opened piece is peeled off. The second joint 2 is located downstream of the first joint in the peeling direction, and when the package film torn in a plane by the first joint arrives when the opened piece is peeled off, it becomes planar. It is a joint that is the starting point for further widening the width of the torn packaging film in the circumferential direction.

When the opening piece is peeled off, the third joint pulls the packaging film torn in a plane by the second joint to the rear of the package with the opening piece, and causes the packaging film to tear in the circumferential direction of the package. It is the joint that is the starting point of the matter. In the present invention, the position from the rolled end to the third joint is 6 mm. By setting this distance, it is possible to reproduce a turning height close to that of an actual product.

As shown in FIG. 1, the curling height is evaluated by observing the package with the opened piece facing up from the side and measuring the height.
<Curl amount of film for opening piece>
The film for an opening piece of the present invention is characterized in that the curl amount is 7 mm or less when it is heat-treated at 120 ° C. for 30 minutes and then cooled at 23 ° C. for 2 hours. By doing so, the amount of curl of the opening piece film itself provided in the package after retort heating is small, so that the opening piece formed from the film itself has a small curl, and when it is provided in a cylindrical package, it is opened. The effect of the present invention of suppressing the occurrence of curling of a piece can be exhibited. The absolute value of the curl amount is preferably small, but 2 to 6 mm is preferable.
As for the amount of curl, a film piece having a size of 20 mm × 20 mm was prepared from the film for opening piece. This film piece was heat-treated in an oven at 120 ° C. for 30 minutes and then taken out to obtain the maximum curl R (diameter φ: mm) of the film cooled at 23 ° C. for 2 hours.

<Base film for packaging>
The base film for a package (also referred to as a base film with an opening piece) provided with the opening piece of the present invention is prepared after the opening piece is heat-treated at 120 ° C. for 30 minutes at 120 ° C. for the opening piece film for forming the opening piece. It is characterized in that the base material film for a packaging body is provided with a surface that becomes concave when cooled at 23 ° C. for 2 hours.
By providing the opened piece in this way, the curl of the opened piece and the shape of the base film for the packaging body after filling with the contents are approximated, so that the curl height can be kept low.
As a method of providing the opening piece on the base film for the packaging body, a method of adhesive, heat fusion, ultrasonic sealing or the like is known, but the method of ultrasonic sealing is preferable from the viewpoint of openability.
As the base material film for the packaging body, a film that can be normally used as a food packaging body can be used, but from the viewpoint of adhesion, a vinylidene chloride-based resin composition similar to the film for opening pieces of the present invention can be used. preferable.

<Manufacturing method of film for opening piece>
The present invention has made it possible to exhibit the effects of the present invention by finding a new method for producing a film for opening pieces.
The method for producing an opening piece film of the present invention is a method for producing an opening piece film containing a vinylidene chloride-based resin, and is characterized by having at least the following steps in order.
1. 1. Step of melt extrusion of vinylidene chloride resin composition 2. 2. Step of relaxing the melt-extruded composition into a film by stretching. Step 1. Re-relaxing the relaxed film with a heating roll. Melt extrusion process, 2. In each step of the step of relaxing the film by stretching, a normal melt extrusion method, for example, an inflation biaxial stretching method can be adopted. In the present invention, 3. It is characterized by having a re-relaxation step by a heating roll.

<Melting extrusion process and stretching and relaxing process>
In the present invention, a usual method for producing a vinylidene chloride-based resin film can be applied. It has a step of melt-extruding a vinylidene chloride-based resin composition, and then a step of stretching the melt-extruded composition into a film and relaxing the composition.
Examples of the melt extrusion method and the stretching method include a tenter method and an inflation method following the T-die method, and in the present invention, it is preferable to stretch by the inflation method after melt extrusion. The inflation method has a simple equipment itself, and can produce a wide film from a small mold.

From the viewpoint of adjusting the curl amount, the draw ratio is preferably 2 to 5 times in the MD direction and 2 to 5 times in the TD direction, and the relaxation rate is 1 to 20% in the MD direction and 1 to 20% in the TD direction. Is preferable.
<Process of re-relaxation with heating roll>

In the step of re-relaxing with the heating roll of the present invention, the film is relaxed in the MD direction and the TD direction after stretching in the stretching and relaxing step, and then the film is relaxed again in the MD direction and the TD direction by contacting with the heating roll. It is characterized by.

The temperature of the heating roll is preferably 80 to 150 ° C., more preferably 100 to 140 ° C. from the viewpoint of adjusting the curl amount. For the same reason, the relaxation rate is 0.5 to 30%, preferably 2 to 20% in the MD direction, and 0.5 to 50%, preferably 10 to 40% in the TD direction.

As the heating roll, for example, a chrome-plated iron roll or the like can be used.

By having the heating roll relaxation step in this way, the effect of the present invention can be remarkably obtained.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited to these Examples.

[Example 1]
(Manufacture of base film for packaging)
Acetyltributylcytolate (ATBC) and dibutylseva are added to a copolymer (100 parts by mass) having a monomer charge mass ratio (VD / VC) of 81/19 at the time of polymerization of vinylidene chloride (VD) and vinyl chloride (VC). A total of 8 parts by mass of Kate (DBS) and epoxidized soybean oil (ESBO) are blended, and a total of 0.3 parts by mass of stearate amide, calcium carbonate and polyglycerin monobehenate are added to make a polyvinylidene chloride resin composition. Got
Next, the obtained polyvinylidene chloride-based resin composition was melt-extruded using an extruder screw having a diameter of 90 mm and then biaxially stretched to obtain a base film for a packaging body.

(Manufacturing of film for opening pieces)
First, acetyltributylcytolate (ATBC), acetyltributylcytolate (ATBC), was added to a copolymer (100 parts by mass) having a monomer charging mass ratio (VD / VC) of 80/20 at the time of polymerization of vinylidene chloride (VD) and vinyl chloride (VC). A total of 8 parts by mass of dibutyl sebacate (DBS) and epoxidized soybean oil (ESBO) were blended, and a total of 0.1 parts by mass of stearate amide and silicon dioxide were added to obtain a polyvinylidene chloride-based resin composition.

Next, the obtained polyvinylidene chloride-based resin composition was melt-extruded using an extruder screw having a diameter of 90 mm and then biaxially stretched by inflation (MD: 2.7 times, TD: 4.1 times). , Double film (two layers of film with a thickness of 30 μm), relaxed by 8% in the MD direction and 7% in the TD direction at a heater setting of 140 ° C., and then 115 hard chrome-plated iron rolls with a diameter of 2 m. By heating to ° C. and bringing the films into contact at a delivery speed of 49.6 m / min and a take-up speed of 46.4 m / min (contact length 4.7 m), the film is relaxed by 6.5% in the MD direction and 25% in the TD direction. Then, a film a for an opening piece was obtained.

(Manufacturing of tubular packaging with opening pieces)
The base film for the packaging body was cut to a width of 80 mm. Further, the film for opening pieces was cut into a width of 20 mm and a length of 13 mm to prepare an opening piece. The base material film is melt-sealed with an ultrasonic seal (the shape of the seal portion is provided at a position 6 mm from the lower end of the opened piece as shown in FIG. 3) (film for opened piece). The pieces were heat-treated in an oven at 120 ° C. for 30 minutes and then melt-sealed so that the concave surface of the curl of the film cooled at 23 ° C. for 2 hours was opposed to the base material film) to obtain a base material film with an opened piece. ..

While molding the base film with an opening piece into a tubular shape, the filling is filled with an automatic filling and packaging machine (manufactured by Kureha Co., Ltd., trade name: KAP3000 type automatic filling and packaging machine), and the base material film with an opening piece is filled with an ultrasonic seal. While converging the ends, it was melt-sealed with a reinforcing tape and sealed to obtain a tubular package.
In the tubular base film with an open piece, the folding width (half the circumference) is 36 mm, and the cut length (filling is removed from the tubular package, and the tubular base film with an open piece is flattened. The conditions were adjusted so that the length when the film was spread out and measured in the longitudinal direction) was 210 mm and the mass was 65 g.

[Example 2]
In the production of the film for opening pieces, after melt extrusion in the same manner as in Example 1, biaxial stretching (MD: 2.7 times, TD: 4.1 times) is performed, and at 140 ° C., 8% in the MD direction, TD. After relaxing 7% in the direction, a hard chrome-plated iron roll with a diameter of 2 m is further heated to 115 ° C. and brought into contact with the drum at a delivery speed of 49.6 m / min and a take-up speed of 43.9 m / min. The film b for the opening piece was obtained by relaxing 11.5% in the MD direction and 21% in the TD direction.
The base material film and the tubular package with the opening piece were manufactured in the same manner as in Example 1.

[Comparative Example 1]
In the production of the film for opening pieces, after melt extrusion in the same manner as in Example 1, biaxial stretching (MD: 2.7 times, TD: 4.1 times) is performed, and at 140 ° C., 8% in the MD direction, TD. After relaxing 7% in the direction, a hard chrome-plated iron roll with a diameter of 2 m is further heated to 115 ° C. and brought into contact with the drum at a delivery speed of 49.6 m / min and a take-up speed of 49.5 m / min. The film c for opening pieces was obtained by relaxing 0.2% in the MD direction and 29% in the TD direction.
The base material film and the tubular package with the opening piece were manufactured in the same manner as in Example 1.

[Calculation method of curl height and curl occurrence rate]
100 tubular packages with an opening piece subjected to the welding treatment shown in FIG. 3 were prepared, heat-treated at 120 ° C. for 15 minutes, and the curling of the opened piece after the treatment was observed. For curling, the opened piece was observed from the side, the height of the part farthest from the tubular package was defined as the "rolling height", and the case where the "rolling height" was 1 mm or more was recognized as "curled". The curl occurrence rate was calculated from the number of curls recognized as having curls out of 100. Observation was performed in a room at 23 ° C. and 50% RH.

[Curl amount]
A 20 mm × 20 mm film piece was prepared from the film for opening pieces. This film piece was heat-treated in an oven at 120 ° C. for 30 minutes and then taken out, and the maximum curl R (diameter φ: mm) of the film cooled at 23 ° C. for 2 hours was defined as the curl amount. Observation was performed in a room at 23 ° C. and 50% RH.

From Table 1, it can be confirmed that the present invention has a small curl amount and a low curl occurrence rate.

Claims (7)

A package made of a vinylidene chloride-based resin composition and having an opening piece having a two-layer structure, and the winding height when welded at a position 6 mm from the winding end of the opened piece is less than 1 mm. A packaging body characterized by that. A film for opening pieces for forming an opening piece, wherein the curl amount when cooled at 23 ° C. for 2 hours after heat treatment at 120 ° C. for 30 minutes is 7 mm or less. An opening piece formed from the opening piece film according to claim 2. In the base film for a packaging body provided with the opening piece, the opening piece has a concave surface when the opening piece film for forming the opening piece is heat-treated at 120 ° C. for 30 minutes and then cooled at 23 ° C. for 2 hours. A base film for a packaging body, which is provided in a base material film for a packaging body in terms of surface. A packaging body using the base material film for the packaging body according to claim 4. The method for producing an opening piece film according to claim 2 , which is a method for producing an opening piece film made of a vinylidene chloride-based resin composition, which comprises at least the following steps in order.
1. 1. Step of melt extrusion of vinylidene chloride resin composition 2. 2. Step of relaxing the melt-extruded composition into a film by stretching. Step of re-relaxing the relaxed film with a heating roll The production of the film for an opening piece according to claim 6, wherein the relaxation rate by the step of re-relaxing with the heating roll is 0.5 to 20% in the MD direction and 0.5 to 40% in the TD direction. Method.

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