JPS5811672A - Package - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides an encapsulated body which has good gas barrier properties and is capable of being heat-killed.

More specifically, the outermost layer is a thermoplastic $13-ester resin layer, a modified f-diolefin adhesive resin layer, a saponified ethylene-vinyl acetate copolymer resin layer, a polyolefin resin layer, etc. A package that is degassed and packaged using a heat-shrinkable multilayer film with good properties such as flexibility and transparency, and then heated for more than 5 minutes in an atmosphere of 100°C to 100°C. It is related to. .

In recent years, in the food processing industry, particularly in the livestock and fish processing fields, regulations on additives to food have become stricter, and the amount of pesticides used has been reduced or almost no longer used. In order to ensure long-term shelf life and freshness, there is a need for packaging that has good oxygen gas barrier properties and can be heat sterilized.On the other hand, from a sales promotion perspective in market development, packaging with excellent transparency and wrinkle-free packaging is required. There is a demand for a package that has a good appearance and is free from scratches, and the present invention provides a package that satisfies these demands.

Conventionally, ethylene-vinyl acetate copolymer resin and vinyl chloride = I have been used for packaging of processed meat products such as hams and sausages.
A laminated heat-shrinkable film with a J-density resin, or a laminated film made of a combination of 4-propylene resin, I-reamid resin, polyethylene resin, etc. are used.

However, packaging bodies using vinylidene chloride-based laminated heat-shrinkable films have excellent oxygen gas barrier properties, but when the food contents are degassed and packaged in phosphorus, heated for 5 minutes in hot water at However, there are also disadvantages in that pinholes sometimes occur in the package and delamination between films occurs.

4. Packaging bodies using a laminated film of liglobilene resin and polyethylene resin or a laminated film of polyamide resin and ethylene resin can be packaged in hot water at a temperature between 100°C and 100°C for 0 minutes after deaerating the food contents. Although it is possible to withstand heat sterilization, the oxygen gas barrier properties are poor, the edible shelf life of the processed meat or fish meat products is short, and at the same time, the laminated film is not heat shrinkable, so it cannot be used after heat sterilization. The disadvantage is that folds and wrinkles occur on the exterior of the package, making it look unsightly.

In this way, the oxygen gas barrier property is good, and the
Requirements such as being able to heat the film for more than 5 minutes in an atmosphere of 0'O ℃, and adding heat shrinkability to the plastic film in order to obtain a package with a good appearance and no bulging or wrinkles. It has not been possible to find a package that satisfies all of the performance requirements.

We carried out research in an effort to create a package that has a high gas barrier property that is stable over a long period of time, exhibits high heat shrinkage in boiling water, and can be heat sterilized for a long period of time. As the outer layer, a multilayer plastic sheet with a laminated structure including a modified I-olefin adhesive resin layer, an ethylene-vinyl acetate copolymer saponified resin layer, a polyolefin resin layer, etc. After the food contents are degassed and packaged using these heat-shrinkable multilayer plastic films, they can be stretched on two wheels at a temperature of 5°C to 100°C.
We discovered that heat sterilization for more than 30 minutes was possible, and after conducting various studies, we completed the present invention.
be.

The purpose of the present invention is to ensure that the food contents, after being degassed and packaged,
It can withstand heat sterilization for more than 5 minutes in an atmosphere of 100°C to 100°C, and has stable oxygen gas/4-reactor properties and moisture resistance over a long period of time, as well as low-temperature heat shrinkability, transparency, and hygiene. It is an object of the present invention to provide a packaging body using an excellent heat-shrinkable multilayer goo two-stick film for food packaging.

The present invention comprises a thermoplastic 4-lyester resin layer (0) as the outermost layer, a modified/Q olefin adhesive resin layer (0), an ethylene-vinyl acetate copolymer saponified resin layer (0), and a 4-lyolefin resin layer (0). ψ), etc., a multilayer glass film with a laminated structure, for example, from the outermost layer) - (B)
-(0)-G)-ψ) It is a multilayer plastic film with a laminated structure in the order of adjacent layers, and the total thickness of the film is 1.
The contents are degassed using a heat-shrinkable multilayer film that has a dimensional shrinkage rate of over 1011 in both length and width after 10 seconds of being placed in an atmosphere at a temperature of 100°C. It is a package that is molded by being packaged and heat sterilized for more than 5 minutes in an atmosphere exceeding (100°C).

Thermoplastic? Polyester resins are those obtained by the condensation of saturated dibasic acids and glycols, such as polyethylene terephthalate obtained from ethylene glycol and terephthalic acid, heptalic acid, isophthalic acid, sepacic acid,
A polyethylene terephthalate copolymer containing saturated dibasic acids such as azobic acid, azelaic acid, glutaric acid, succinic acid, and sinuic acid as a copolymer component, and as a diol component, 1,4-cyclohexane dimetatool, diethyl glycol, It is a polyethylene terephthalate copolymer or a blend thereof containing Robyrenda Licol as a copolymer component.

The saponified ethylene-vinyl acetate copolymer resin has a softening temperature (4-tester method) of 150 to 175°C, and a trityrene content of 6 to 9096 degrees of saponification per vinyl acetate in the flomole-1 copolymer. As described above, it has extremely high oxygen gas barrier properties in a dry state.

The modified polyolefin adhesive resin layer is made of modified polyethylene adhesive resin whose molecular chain end is treated with a reactive functional group such as unsaturated carganic acid, modified lipstick adhesive resin, and modified ethylene-acetic acid. These include vinyl copolymer adhesive resins, among which modified ethylene-vinyl acetate copolymer adhesive resins have particularly good adhesive performance, and modified I dipropylene adhesive resins have good heat resistance. preferable.

The polyolefin resin layer is made of low density ethylene resin,
Medium density? Polyethylene resin, high-density polyethylene resin, ethylene-vinyl acetate polymer resin, polypropylene resin, copolymers of each resin, etc., and 11 [1] or a blend thereof.

The total thickness of the plastic film used for urine invention is 10
200/Jm, and glass films with a thickness within this range are suitable for shrink packaging of foods.

The present invention is aimed at shrink packaging and heat sterilization packaging for food products, so a wrapped iron object such as a meat eggplant product is filled into a bag made of a heat-shrinkable multilayer film, and after the inside is degassed, The mouth part is heat-sealed and heat sterilized at the same time as shrink wrapping by placing the bag in boiling water at 100°C to 100°C or in a heating chamber for more than 5 minutes.

After packaging the food contents in a heat-shrinkable multilayer film and deaerating the inside, the multilayer film shrinks when the food contents are heated, and the food contents and the multilayer film are in close contact, so that the multilayer film does not fold or wrinkle. A package with a good appearance can be obtained, and at the same time, a package with this appearance can be heat-killed. The heat-shrinkable multilayer film for this purpose has at least 10
It is placed in an atmosphere at a temperature of 0°C, and after 10 seconds it becomes 1 in both the vertical and horizontal directions.
It is necessary to have a dimensional shrinkage rate exceeding 0.
It can withstand heat sterilization in an atmosphere of 100°C to 100°C for more than 5 minutes, and the heat-sealed portion does not peel off.

- The method for deaerating food contents is carried out by a single method or multiple methods, in which the food contents are filled into a twill-shaped bag made of the heat-shrinkable multilayer film of the present invention, and the packaging is carried out at 760 vmH.
After the inside of the bag is degassed at a degassing pressure of f, the opening is heat-sealed.

The method for producing a heat-shrinkable multilayer film of the present invention includes a thermoplastic polyester resin layer as the outermost layer, a modified polyolefin adhesive resin layer, an ethylene-vinyl acetate copolymer saponified resin layer, a 79-year-old reflex resin layer, etc. A multi-layer Norasnack sheet having a laminated structure including: The multi-layer glass sheet is melt-extruded from the laminated layer by a co-extrusion method using a plurality of extruders, cooled and solidified, and then heated at 70°C to 100°C. It is characterized in that it is reheated to a grinding temperature within the range of 0.degree. C., stretched two-wheeled by 1.5 times or more in the machine direction and 5 times or more in the transverse direction, and then cooled. - It is necessary for the laminated structure of the multilayer plastic sheet before stretching to have a thermoplastic resin ester ms layer as the outermost layer for packaging the food contents, and the coextrusion method for the multilayer sheet includes a tube using a circin-lar die. It is preferable to extrude it into a shape or extrude it into a flat shape using a T-die.

Next, this tubular sheet or flat sheet is reheated to a stretching temperature within the range of 70°C to 100°C, and subjected to simultaneous biaxial stretching in longitudinal and lateral directions or sequential two-wheel stretching using a known chain or tenter stretching method. By stretching, a film with good appearance can be produced.

In the above manufacturing method Ki, after deaerating and packaging the processed meat product with the heat-shrinkable multilayer film of the present invention,
After heat sterilization by immersing the package in boiling water at 0°C for ω minutes, the packaged meat product can be stored for a long period of time without any abnormalities such as creases or damage to the package that would deteriorate its appearance. Ta.

The main effect of the O-packaging body of the present invention is that the polyolefin resin is bonded to the thermoplastic ester resin, which is extremely difficult to stretch at a temperature of 100°C or less, and the saponified ethylene-vinyl acetate copolymer resin. This multilayer structure enables biaxial stretching of the thermoplastic-lyester resin and saponified ethylene-vinyl acetate copolymer resin layer at a temperature of 100°C or less, and also makes it possible to After the contents are degassed and packaged using a heat-shrinkable multilayer film, the outermost layer is a polyester resin layer. Nine things have been discovered that sterilization is possible.

The stretching ratio of biaxial stretching is 1.5 times or more in both length and width.
Good tL< is 2 times no! It's IN4 times.

In order for the dimensional shrinkage in the vertical and horizontal directions to exceed 410 - after 10 seconds when placed in air at 100°C, it is necessary to expand the koji by at least 1.5 times.

Dimensional shrinkage rate (ri) is the length of the original film is 4, and the length of the film after a certain period of time is t when placed in an atmosphere at a constant temperature.
Then, a -100-C1@-4)7 is a value defined by -.

Book'A@C) Heat-shrinkable multilayer film, 70℃ to 90℃
When placed in the atmosphere of 'C, the dimensional shrinkage rate after 10 seconds is 2.
01! It is preferable that the film be stretched between 50 and 50° C. To obtain such a film, biaxial stretching is preferably carried out at a temperature of 70° C. to 90° C., which is 2 times to 4 times both in the length and width directions.

Next, examples of the present invention will be described.

11K shows a cold example of the present invention.

All of the original sheets of the films of Examples NILI to Na7 shown in Table 1! / Manufactured by bay coextrusion method,
It can be melt extruded from a multilayer die to produce 200 pm thick sheets.

The film of Example N11gg was produced by T-die coextrusion method.
I made a 5 op dense sheet.

Next, after reheating the sheet using a two-wheel stretching device,
A film with a thickness of about 50 pm was made by stretching 2 times the kg in both length and width, and the film was evaluated for stretchability, heat shrinkability, oxygen gas barrier property, package heat testability, etc.

Films with good line transparency and smoothness in appearance and no stretching unevenness were rated as good, and those with stretching unevenness due to necking or poor smoothness and transparency were rated as poor.

The thickness of each layer of the film is determined by the order of composition and the order of thickness composition.
They are shown correspondingly from left to right.

For heat shrinkability, the film was placed in boiling water, taken out after 10 seconds and cooled, and those exhibiting a dimensional shrinkage of more than 10 in both length and width before and after boiling were evaluated as good, and those that were lower than that were evaluated as poor.

Oxygen gas barrier membrane, test method 8TM-→-1434
In accordance with
The oxygen gas barrier properties are good below IJ''24hr・muT blade.

The package heating test property was determined by testing the various films mentioned above at length 13a+.
Processed into a three-sided sealed acid shape with a width of 13 all, grilled pork, which is an irregularly shaped processed meat product with a center diameter of approximately 200 f in weight, was filled as food content into a 760 m 11 g bag.
After evacuating the inside of the bag at a degassing pressure of 1, the opening is heat-sealed in the degassed state.

As a sealing method, a hot plate sealer heated to 130° C. is used, and sealing is performed at a hot plate pressure of 2 V−1 and a heating time of 1 second.

The thus obtained package t is heated in hot water at 80° C. or 100° C. for 5 minutes or at the same time as shrink wrapping, and the test quantity is 10 pieces at the same test level.

After heating, a product with no degassing leakage due to a broken seal or pinhole is considered to be in good condition, and a product with even one degassing leak out of 10 items is considered to be defective.

In the overall evaluation of the package, a film that is good in all of the film appearance, heat shrinkability, oxygen gas barrier property, and package heat testability is considered good (0 mark), and a film that is defective in any of the following is considered poor (x mark). ).

In gin, the thermoplastic $ IJ ester resin is a copolyester resin manufactured by Eastman Chemical Co. with a melting point of 260°C and a glass transition point of 70°C, and an ethylene-vinyl acetate copolymer saponified resin has a softening temperature of 70°C. (Flow tester method) Glue at 170℃, epal resin, modified I dipropylene adhesive resin, modified ethylene.
Vinyl acetate copolymer adhesive resin Modified polyethylene adhesive resins are Modic Ashi manufactured by Mitsubishi Yuka, and low density polyethylene resins are Sumikase/Ashi and ethylene-acetic acid manufactured by Sumitomo Chemical ■ with a melting point of 105°C. Vinyl copolymer resin is Sumitomo Chemical Evatate (vinyl acetate content: 8 weight)
The polypropylene resin is an ethylene-propylene/random copolymer polypropylene resin manufactured by Sumitomo Chemical with a softening temperature of 140°C.

l! Example? As is clear from &L1 to Arashi 5, the packaging of the present invention has transparency, a packaging appearance with no folding and wrinkles due to low-temperature heat shrinkability, extremely good oxygen gas barrier properties, and can be used in an atmosphere of 80°C to 100°C. The package becomes a package that can be heated for 5 to 60 minutes inside.

As is clear from Examples N16 to Na8, the package containing the unstretched polypropylene resin layer as the outermost layer can withstand the package heat test, but has no heat shrinkage and has poor oxygen gas barrier properties. It was found that even if a package containing a polypropylene resin layer inside the film was placed, the outer layer of the heat-shrinkable film would peel off, and the package would have poor packaging heat test properties. /17 There are 411 cases in which packages with ethylene resin as the outermost layer cannot withstand the package heating test for 100°C ω minutes, and these packages have poor appearance, thermal shrinkage at low temperatures, oxygen gas purging properties, and )℃ノj[11
It is a package that satisfies all of the package heating test properties in an atmosphere of 00° C. for more than 5 minutes and has a V%.

Claims (6)

[Claims] (1) The thermoplastic I-lyester resin layer) is the outermost layer, the modified 4-lyolefin adhesive resin layer -), the saponified ethylene-vinyl acetate copolymer mk layer (0), and the 4-lyolefin resin layer ψ. ), the total thickness of the mosquito film is l.
〇- to 200711111, it is placed in an atmosphere at a temperature of 100℃, and the dimensional shrinkage rate after 10 seconds is 41 in both length and width.
(A package characterized by deaerating the contents in a heat-shrinkable film exceeding 1st degree and sterilizing it by heating for more than 5 minutes in an atmosphere exceeding 30°C. (2) The multi-71 glass film has a laminated structure in which the outermost layer (4) - (B) - (0) - (uniform) is adjacent to each other in the order of (11) the outermost layer. packaging. (3) The package according to claims (1) and (2), wherein the thermoplastic resin/lyester resin layer) is an I-liester resin obtained by condensation of a saturated dibasic acid and glycols. . (4) The modified diolefin adhesive resin layer Φ) is
Degeneration I! The package according to claims (1) to (3), which is a lopylene resin, a modified tetraethylene resin, a modified ethylene-vinyl acetate copolymer resin, or a blend of these resins. (5) Claims in which the ethylene-vinyl acetate copolymer saponified resin layer (0) is a resin having a saponification degree of 90 or more with respect to vinyl acetate in the ethylene content 5 to 75 mole 1 copolymer. The package according to items (1) to (4). (6) in the polyolefin resin layer) is a polyethylene resin, an ethylene-vinyl acetate copolymer resin, a polypropylene resin, or a blend of these resins, claims (1) to (5) Packaging as described in section.