JPS62275675A - Cylindrical packed material - Google Patents

Abstract

PURPOSE:To make it possible to cut a film on the surface of packed material when it is folded, by forming a cylindrical packed material by the use of a vinylidene chloride-methyl acrylate copolymer resin containing a plastizer in a specific ratio and making the packing ratio of contents thereof in a specific ratio. CONSTITUTION:In a cylindrical packed material 1 made of a vinylidene chloride resin film wherein both end parts 2 and 2' of the cylindrical film are sealed, unfluid contents are packed into the interior of the packed material. The vinylidene chloride resin is a vinylidene chloride-methyl acrylate copolymer resin which has <=4wt% content of plasticizer such as diisobutyl adipate, etc., and 4-7wt% methyl acrylate component. The contents of the packed material 1 has >=90% packing ratio. When the cylindrical material is bent along in the longer direction and folded, the film on the surface of the packed material can be cut and the contents can be readily taken out by taking advantage of the cut. Moreover, the packed material can be provided without damaging characteristics such as gas barrier properties.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] Mainly processed meat foods such as livestock meat and fish, processed dairy products such as cheese and butter, confectionery such as Western cakes and jelly, etc. This invention relates to an improved technology for a cylindrical package made of a vinylidene chloride resin film containing .

[Prior art]

Cylindrical packaging bodies made of vinylidene chloride resin films are widely known. These are generally carried out using an automatic filling and packaging machine commercially available as, for example, △DP (trade name, manufactured by Asahi Kasei Corporation) or KAP (trade name, manufactured by Kureha Chemical Corporation).
5-34044, that is, a flat long film is continuously bent so that both sides thereof overlap, and the overlapping parts are thermally welded (sealed) to form a cylindrical film. After filling the inside with the fluidized contents, seal it with an appropriate distance (
It is also widely known that it can be manufactured by a series of continuous automatic bag-making, filling, and ligating operations, including wire ligation, individual cutting, and cylindrical packaging.

One drawback of this package is that the outer film is made to be strong so that it can withstand the stress of handling such as transportation and conveyance, and maintains the spoilage and contamination resistance of the contents. Therefore, it is difficult to take out the contents, especially without using a knife, etc., and use it for the purpose. Therefore, even if it is known that it has excellent preservation and hygiene, There are restrictions such as the inability to apply this package to, for example, toy confectionery that children can enjoy and eat.

On the other hand, as a method for facilitating the removal of the outer skin film, Japanese Patent Publication No. 51-8080 and Utility Model Publication No. 49-1
There is a technique disclosed in Japanese Patent No. 9021. In short, a strip-shaped material that is stronger than the outer skin film is attached to a part of the flat body or a part of the seal line, and by pulling this strip-shaped material, a part of the cylindrical film is torn off. The proposal is to provide an easy-to-open part to use that part as a cut in the outer skin film. However, with this technology for providing an easy-to-open part, the probability of forming a tear-off cut is close to 100%. It is extremely difficult to guarantee this, and therefore it has only been used for some cheese and Wiener sausage packaging, and has not yet become widely used.

The main reason for this is that installing high-opening areas requires advanced welding equipment and technology that can set and manage conditions with high precision, whereas the packaging itself cannot add the cost that corresponds to its technological value. This is because of the current situation.

(Problems to be solved by the invention) A novel cut is formed which is completely different from the conventional idea of forming a cut, that is, the surface film is cut by bending and curving the package in the longitudinal direction. In order to make it easier to take out the contents by using The goal is to be able to provide it without compromising it.

(Means for solving the problem) The differences from conventional cylindrical packaging bodies using vinylidene chloride resin films are as follows: 1) The vinylidene chloride-1-nodene resin forming the film has Plasticizer content is 4
% by weight or less. A vinylidene chloride-methyl acrylate copolymer resin containing 4 to 7% by weight of methyl acrylate component is used.

2) The contents of the package shall be filled with non-flowable substances at a filling rate of 90% or more.

This is a combination of requirements 1) and 2) above.

The contents of the present invention will be explained in detail below using drawings and the like.

FIG. 1 is a model diagram showing the cutting process in which when the cylindrical package of the present invention is bent and curved in the longitudinal direction, the film on the outer periphery of the curve begins to tear and cut. FIG. 1 is for explaining how a cut is formed to form an opening corresponding to the effect of the present invention.

In Fig. 1, the initially straight cylindrical packaging body (shown by dotted lines) 1 has been curved at both ends 2 and 2' so that its longitudinal center is curved at an angle θ. bring them close together. If the angle θ reaches approximately 60 degrees or less, the film itself will often be cut as the contents are cut, but Figure 1 shows the assumed state immediately before cutting. In other words, the scene in which the film is stretched along the outer periphery of the content to be curved, and the film itself cracks as the content breaks is represented by a solid line.

In the package of the present invention, this breakage or cut is used to tear the film into a thin strip along the circumference of the package, or to push out the contents from the cross section of the cut, making it easier to take out the contents. The purpose is to promote

In this case, the contents must be a non-flowing substance that does not flow at room temperature, preferably a solid that does not flow, and the filling ratio, expressed as the ratio of the volume of the true contents to the volume of the package, must be 90% or more. . The reason for this is to bend the package and break the film together with the contents, and to ensure that the break occurs easily.For example, if the contents are fluid and the filling rate is less than 90%, This makes it extremely difficult for the film to break.Also, if the contents are fluids such as liquids, when the film breaks, all the contents are squeezed out at once and spread over a wide area. This results in the problem of the particles being scattered all over the place.

Next, the characteristics of the resin composition that gives the above-mentioned rupture properties are vinylidene chloride containing 4 to 7% by weight of methyl acrylate component.
The objective is to make the methyl acrylate copolymer resin into a film so that the plasticizer content m is 4% by weight or less.

First, the reason why the methyl acrylate component is 4 to 7% by weight is that the film itself has gas barrier properties, impact resistance,
This is to satisfy the balance of other quality requirements for a packaging material, such as breakage resistance of the sealed portion, which is necessary to reliably preserve the contents when packaged.

In the vinylidene chloride-methyl acrylate copolymer resin that forms the basis of these film properties, the plasticizer content is 4.
The need for the plasticizer content to be below 4% by weight is such that, for example, if the plasticizer content is 4% by weight or more, the resulting film will have increased flexibility;
To make it difficult to obtain the effect of bending and breaking the package. In general, the amount of plasticizer in the film resin should be kept small for reasons other than the desired breaking effect, such as reducing gas barrier properties and increasing the appearance of plasticizer seeping out from the surface (bleeding). .

However, as long as vinylidene chloride resin is used as the target resin for the film, in order to maintain extrusion film formability industrially,
It is not easy to reduce the amount of plasticizer. This fact is no exception even in the present invention, which targets vinylidene chloride resins containing 4 to 7% by weight of methyl aliclate.

The present invention utilizes the following effects to achieve both the above-mentioned extrusion film properties and reduction in the amount of plasticizer.

Figure 2 is an experimental diagram, where the horizontal axis is the initial plasticizer content in the resin, the vertical axis is the proportion (% by weight) of plasticizer that can be dissipated during the extrusion film forming process, and the solid line is the main content. The results shown in Fig. 2, which are a summary of the experimental results for the resin targeted by the present invention, indicate that in the case of the resin targeted for the present invention, a relatively large amount of plasticizer was omitted during the extrusion-film forming process. It can be seen that it has an action function that can be dispersed. In the present invention, by utilizing this function, extrusion
During film formation, a large amount of plasticizer is used to overcome the poor film forming properties of the vinylidene chloride-methyl acrylate copolymer resin. It reaches a stage called the plastic state.
We have succeeded in creating a material with a low plasticizer content. The vinylidene chloride-methyl acrylate copolymer resin used in the present invention has a weight average molecular weight (according to GPC method) of 70,000 to 2
50,000, and the ratio to the number average molecular weight determined by the same GPC method (ie, weight average molecular weight/number average molecular weight) is preferably in the range of 2.0 to 3.0.

More preferably, the weight average molecular weight is in the range of 80,000 to 130,000, and the ratio to the number average molecular weight (weight average molecular weight/number average molecular weight) is in the range of 2.0 to 2.4.

The weight average molecular weight and number average molecular weight referred to here are
The value was determined by the method described in No. 9-240483, that is, the GPC (gel permeation chromatography) method.

The plasticizer used in the present invention refers to a liquid plasticizer known as a plasticizer for vinyl chloride resin. Among them, from the viewpoint of food safety and hygiene, liquid plasticizers are carefully selected from aliphatic dibasic acid esters, citric acid esters, fatty acid esters, polyesters, etc., and preferably diisobutyl adipate, diisobutyl adipate,
These include dibutyl sepatate and tributyl acetyl citrate.

More preferably, the above plasticizer and diisobutyl adipate are used in combination (for example, if the diisobutyl adipate component is
0% by weight or more) is desirable.

Qualitative and quantitative information on plasticizers can be found in publications related to analysis, such as the ``Polymer Analysis Handbook'' (Japan Analytical Chemistry Kinen 19).
It can be carried out by a method using a gas chromatograph and a mass spectrometer according to the solvent extraction method described in 1985).

The plasticizer escape rate is the ratio (wt%) of the amount of plasticizer (B) that escapes during the extrusion-film forming process to the initial content 1 (A).
, that is, it is necessary.

The evaluation method and evaluation scale used in the present invention are shown below.

a) Oxygen gas permeability ASTM D-3985 quasi-compliant (unit: cc/rtt -24Hr -atm at
20℃] Evaluation scale evaluation symbol Standard value ◎; Less than 3cc Q: 3cc or more - less than 5cc △; 5cc or more - less than 10cc ℃90%R
H) Evaluation scale evaluation symbol Water Q value◎: Less than 33○; 33 or more - less than 59△: 5g or more - less than iog Evaluation scale evaluation symbol based on horizontal average value Standard value ◎; 3 in 1000 or more ○: 700 Ky or more to less than 1000 Kg Δ:
40ONyJX above ~ 7CJOK less than 9x:
Less than 400Kg d) Impact strength based on ASTM-D1822* [Unit: K! j-cmat5°C) Evaluation scale evaluation symbol determined by the vertical and horizontal average values Standard value ◎; 10Kg-cm or more○: 7 to 9-cm or more to 10 to less than 9-cm△
: To 5! More than J-cm to 7! Less than j-cm X: 5
Less than Kl-cm e) Bag breakage strength at sealed part Ligate one side of the sealed cylindrical film with aluminum wire, insert an air nozzle from the other side, and
0. The broken part was submerged in a 120℃ liquid using a rubber tube to prevent air from leaking, then air pressure was gradually applied until it burst, and the gauge pressure at the point of burst was checked.
It was defined as bag breakage strength.

[Unit: Kl/crA] Evaluation scale rating symbol Standard value ◎: 0.8 to 3 or more 0: 0.5Kg or more to 0.8 to less than 3 △;
More than 0.3'J~less than 0.5Kg x:
Less than 0.3Kg f) Package bending test Sensory test when the cylindrical package is bent in the longitudinal direction as shown in Figure 1 Evaluation scale Evaluation symbol Standard value ◎: Cut X; Do not cut g) Thickness based on ASTM-D374 (unit: μ) The content of the present invention will be explained in detail below using experimental examples and examples. In addition, the base resin used in the following experimental examples and examples has a ratio of vinylidene chloride component and methyl acrylate component:
The component ratio is 97:3 (nylidene chloride (wt%): methyl acrylate (wt%) the same below), 96:4, 95:
It is a vinylidene chloride-based resin in which 1% by weight of epoxidized linseed oil is added as a heat stabilizer to each of five types of copolymers of 5.93Nia, 92.5Nia, and 5.

This base resin can be produced by the method described in Japanese Patent Application No. 59-240483.

Experimental Example 1 A mixture of equal amounts of diisobutyl adipate and dibutyl sepatate (both liquid plasticizers) was added to the base resin in which the component ratio of vinylidene chloride component and methyl acrylate component was 96:4 at 2% by weight and 4% by weight. % by weight, and 6% by weight were added and mixed to obtain three types of resins.

These resins are supplied to a melt extrusion chamber, melted, extruded into a tubular shape through the slit of an annular die attached to the tip of the extrusion chamber, supercooled, and then blown into a tubular shape. This tubular film was pinched and crushed into a flat film, and then introduced into a heating furnace whose temperature was controlled at 100°C with hot air, and heat-treated (pass length of approximately 10 m).
), then cooled with a cooling roller and folded to a width of 1300m
A film having a thickness of 40 microns (two layers) was wound onto a bobbin at a winding speed of 20 TrL/min.

These films were slit into 22 rows of 56# width and wound up onto a bobbin with the pinch creases removed at both ends.

For the three types of films obtained, the residual plasticizer ♀ in the films was measured, and the plasticizer dissipation rate (% by weight) was determined.

The results are shown in Figure 2.

The results shown in Figure 2 indicate that the vinylidene chloride-methyl acrylate copolymer resin composition of the present invention has the property that the plasticizer in the raw material resin escapes during extrusion, film forming, and heat treatment steps. It shows.

Example 1 The component ratio of vinylidene chloride component and methyl acrylate component is 97:3, 96:4, 95:5, 93:7°92
．． 5: A mixture of diisobutyl adipate and dibutyl sepatate (both liquid plasticizers) (70% by weight of diisobutyl adipate:
Dibutyl sepatate (30% by weight) was added and mixed. Using these resins, the extrusion film forming slit method conditions were the same as in Experimental Example 1, except that the treatment temperature in the heating furnace was changed to 110°C compared to the extrusion film forming slit method described in Experimental Example 1. Film thickness: 40 microns (2 layers), width: 56 m (7), 5 types of films (■
~V) were prepared and each was wound onto a bobbin. The amount of residual plasticizer in these films amounts to approximately 3% by weight.

The physical properties of the five types of films obtained were evaluated by the method described in the text.

Next, these films are ADP (product name, Asahi Kasei)
The bag was suspended in a cylindrical bag (folding diameter: 25 rNri) and sealed under conditions such as a film running speed of 25 TrL/min and an electrode surface pressure (pressure) of 3009 mm.

The electrode plate current at this time was set at the midpoint of the sealable range.

The resulting bag products were examined for bag breakage strength at the seal area using the method described in the text.

Next, from among the films TV to V, the component ratio of vinylidene chloride component and methyl acrylate component is 96:4,
Select 93 Near film and use these and Asahi Kasei ■;
Thickness: 40 microns (two layers) width: 56 m
A sealed package (diameter: 15 #, length: 150 m, weight: 24 J) was prepared by suspending the bag in a cylindrical shape under the same conditions as above, filling the contents with cheese, and applying wire ligatures.

The filling rate was 95% in all cases.

The resulting package was subjected to a bending and cutting test using the method described in the text.

The results of the physical properties of the film and the bag breakage/strength of the sealed portion are shown in Table 1, and the results of the package bending test are shown in Table 2.

According to the results in Table 1, the product of the present invention has gas barrier properties,
It can be seen that it has the required qualities as a packaging material, such as impact resistance and breakage resistance of the sealed part, which are necessary to reliably preserve the contents when packaged.

According to the results shown in Table 1 and Table 2 below, the cylindrical package of the present invention can be formed by forming a new cut that is completely different from the conventional concept of cut formation, that is, by bending and curving the package in the longitudinal direction. This alone shows that it is necessary to cut the surface film and take out the contents through the cut.

Table 2 (Effects of the present invention) By having the above-described structure, the present invention forms a new cut that is completely different from the conventional idea of making a cut, and makes it easier to take out the contents by using the cut. This is an excellent invention that can provide a packaging body with this function without impairing other properties required for the packaging body, such as gas barrier properties, impact resistance, and tear resistance of the sealed portion. I can say that.

[Brief explanation of the drawing]

Fig. 1 is a model diagram explaining the effects of the present invention, and Fig. 2 is an experimental diagram explaining the technical content of the present invention, and each is a characteristic diagram showing the usefulness of the film. 1... Tubular packaging body patent applicant Asahi Kasei Industries Co., Ltd. Agent Patent attorney Kazuya Nozaki Figure 1 Amount of plasticizer added (% by weight) Procedural Negotiations (spontaneous) November 6, 1985

Claims (1)

[Scope of Claims] 1) A vinylidene chloride resin in which the inside of a cylindrical vinylidene chloride resin film is filled with a non-flowing content, and both ends of the cylindrical film are sealed. In the cylindrical package made of film, 1) the vinylidene chloride resin is a vinylidene chloride-methyl acrylate copolymer resin having a plasticizer content of 4% by weight or less and a methyl acrylate component of 4 to 7% by weight. 2) The filling rate of the contents is 90% or more. A cylindrical packaging body made of a vinylidene chloride resin film, which is characterized in that the film on the surface of the packaging body can be cut when the cylindrical body is curved and bent in the longitudinal direction.