CN104608450B - Inner tape, method for producing inner tape and packaging container using inner tape - Google Patents

Abstract

The invention provides an inner tape for a packaging container, the outer layer of the inner tape, another outer layer, an intermediate layer and another intermediate layer all adopt a blend of low-density polyethylene and linear low-density polyethylene; the inner tape The opening formed at the top of the container can be reliably sealed from the underside, and the inner band can be easily and quickly broken near the edge of the opening when the pull-tab is peeled off; the invention also provides a method of manufacturing the inner band And a packaging container using said inner tape.

Description

Inner tape, method for manufacturing inner tape and packaging container using inner tape

technical field

The invention relates to an inner tape for a packaging container, and also relates to a method for manufacturing the inner tape and a packaging container using the inner tape.

Background technique

A packaging container for food has a packaging container body, an opening provided at the top of the container for pouring out the food, opening means such as a spout, lid or cap, and a pull tab or straw. FIG. 2 shows an example of a packaging container sealed with a pull tab 4 . The packaging container 1 has a main body 2 and an opening 3 for food provided at the top of the container.

FIG. 1 is a cross-sectional view showing an opening and a portion around the opening. In order to seal the opening 3 , the opening 3 is covered with the handle 4 and sealed along the outer periphery 3 a of the opening 3 from above the handle 4 . In addition, the opening 3 is covered with the inner tape 5 from below, and the lower surface of the outer periphery 3a of the opening 3 and the inner surface of the pull tab 4 are welded and bonded to each other so as to be sealed.

In order to pour out the food, the unsealed part of the pull tab 4 is pulled up, and the inner band 5 is broken near the edge portion of the opening to tear the pull tab 4 and break the seal of the opening 3 . In the above process, it is very important whether the packaging container is easy to tear, that is, when the pull tab is peeled off, the inner tape must be cut off quickly without leaving fibers or small pieces.

Most of the currently used inner tapes are laminated films obtained by dry lamination. However, in the tearing process, due to the different types of each layer of film, it is difficult to achieve a balance of adhesive force between each layer of film, and the force direction of the inner belt is not fixed, so it is easy to cause film damage. Displacement of the inner layer (i.e. poor peel strength) often leads to incomplete cutting of the inner belt. This often leads to a low pass rate of the inner belt, which requires the use of special raw materials and equipment to improve, with high cost and low efficiency.

Therefore, it is necessary to develop a kind of inner tape with balanced cohesive force of each layer of film, very easy to tear and high yield of preparation.

Contents of the invention

One aspect of the present invention provides an extremely functional inner belt which is a laminate comprising: an outer layer made of a blend of low density polyethylene and linear low density polyethylene; an outer layer made of low density polyethylene Intermediate layer made from a blend of LLDPE and LLDPE; adhesive layer; ethylene vinyl alcohol copolymer barrier layer; another adhesive layer; made from a blend of LDPE and LLDPE and another outer layer made of a blend of low-density polyethylene and linear low-density polyethylene, laminated in the order described above.

In one embodiment, the weight ratio of low density polyethylene and linear low density polyethylene blend in the outer layer and another outer layer is about 1:5 to 5:1, preferably 1:2 to 2: 1, more preferably 1:1.3.

In one embodiment, the weight ratio of low density polyethylene and linear low density polyethylene blend in the middle layer and another middle layer is about 1:5～5:1, preferably 1:2～2: 1, more preferably 1.5:1.

In one embodiment, the binder is ethylene-vinyl acetate copolymer, or an ionomeric polymer prepared by cross-linking molecules with metal ions in ethylene-methacrylic acid vinyl copolymer, ethylene methyl Acrylic copolymer, ethylene acrylate rubber, ethylene-vinyl acetate copolymer, liquid rubber modified adhesive, polyurethane modified adhesive, elastic microsphere high-strength adhesive, and modified nanoparticle adhesive and through One or any combination of substances obtained by modifying any of the above substances.

Another aspect of the present application relates to a method of manufacturing an inner band, comprising the steps of:

Coextrude the following ingredients in the order described below: LDPE and LLDPE blend; LDPE and LLDPE blend; binder; ethylene vinyl alcohol copolymer ; adhesives; low density polyethylene and linear low density polyethylene blends; low density polyethylene and linear low density polyethylene blends;

An inner belt is obtained which is a laminate comprising: an outer layer made of a blend of low density polyethylene and linear low density polyethylene; an intermediate layer made of a blend of low density polyethylene and linear low density polyethylene layer; an adhesive layer; an ethylene-vinyl alcohol copolymer barrier layer; another adhesive layer; another intermediate layer prepared by blending low density polyethylene and linear low density polyethylene; Another outer layer made from a linear low density polyethylene blend, these layers were laminated in the order described above. The raw materials used in the above method are all commonly used raw materials, without special requirements, and each step of lamination can be carried out under basically the same preparation conditions, and there is no special requirement for equipment.

Another aspect of the present application relates to a packaging container using the above inner tape.

These and other features, aspects and advantages of the present application will be better understood with reference to the following detailed description.

Description of drawings

FIG. 1 is a cross-sectional view showing an opening and its vicinity.

Fig. 2 is a perspective view showing an example of a packaging container.

Symbol Description

1. Packaging container

2. The main body of the packaging container

3. Opening

4. Pull tab

5. Inner belt

3a Periphery of the opening

detailed description

The present disclosure may be more readily understood by reference to the following detailed description of the preferred methods of practicing the invention, together with the included Examples. In the following specification and claims there will be reference to a number of terms which are defined to have the following meanings.

Singular forms include plural referents unless the context clearly dictates otherwise.

"Optional" or "optionally" means that the item or event described thereafter may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximate terms in the specification and claims are used to modify the quantity, which means that the present invention is not limited to the specific quantity, but also includes acceptable modifications that are close to the quantity and will not cause changes in the relevant basic functions. Accordingly, a numerical value modified by "about", "about", etc., means that the present invention is not limited to the precise numerical value. In some instances, approximate terms may correspond to the precision of the instrument for measuring the value. Throughout the specification and claims of this application, range limitations may be combined and/or interchanged, unless otherwise stated such ranges include all subranges contained therebetween.

"Polymer blend" refers to a physical mixture of two or more homopolymers, copolymers or homopolymers and copolymers with different molecular structures. Generally, there is no covalent bond between the macromolecules of the two components. The mixing of polymers is an endothermic process and is a heterogeneous system in which one polymer is dispersed in another. The purpose of blending is to prepare polymer materials with improved or unique properties in certain properties. Polymer blends are the earliest heterogeneous polymers. As early as the beginning of the 20th century, there was a patent report on the preparation of impact-resistant polystyrene by blending. Blending is relatively simple in technology, and the selection range of components is large, and it can be easily made into new materials with special properties, so it develops rapidly.

A first aspect of the present invention provides an extremely functional inner belt which is a laminate comprising: an outer layer made of a blend of low density polyethylene and linear low density polyethylene; Intermediate layer made of a blend of polyethylene and linear low density polyethylene; adhesive layer; ethylene vinyl alcohol copolymer barrier layer; another adhesive layer; blended from low density polyethylene and linear low density polyethylene and another outer layer made of a blend of low-density polyethylene and linear low-density polyethylene, laminated in the order described above.

The term "low density polyethylene (LDPE)", as used in this application, is a plastic material which is suitable for thermoplastic molding. Low-density polyethylene is mainly used for film products, but also for injection molding products, medical equipment, pharmaceutical and food packaging materials, blow molding hollow molding products, etc.

The term "Linear Low Density Polyethylene (LLDPE)" as used in this application is non-toxic, tasteless and odorless. Compared with low-density polyethylene, it has a higher softening temperature and melting temperature, and has the advantages of high strength, good toughness, high rigidity, heat resistance, and cold resistance. It also has good environmental stress cracking resistance and impact resistance. Strength, tear resistance and other properties. And acid, alkali, organic solvents and so on.

In one embodiment, the density of LDPE usable in this application is 0.910-0.925 g/cm ³ , preferably 0.918-0.925 g/cm ³ , more preferably 0.924 g/cm ³ .

In one embodiment, the LLDPE usable in the present application has a density of 0.910-0.930 g/cm ³ , preferably 0.915-0.925 g/cm ³ , more preferably 0.918 g/cm ³ .

In one embodiment, in the inner belt of the present application, the thickness of each layer of film is: the outer layer is 1-9 microns, preferably 3-7 microns, more preferably 5 microns; the middle layer is 3-18 microns, preferably 7-16 microns micron, more preferably 10 microns; adhesive layer 2-10 microns, preferably 4-9 microns, more preferably 6 microns; barrier layer 3-12 microns, preferably 4-10 microns, more preferably 8 microns; another intermediate layer 3 ~18 microns, preferably 7~16 microns, more preferably 10 microns; the other outer layer is 1~9 microns, preferably 3~7 microns, more preferably 5 microns.

In one embodiment, in the outer layer of the inner tape of the present application, the weight ratio of low-density polyethylene and linear low-density polyethylene is 1:5 to 5:1, preferably 1:2 to 2:1, more preferably 1 :1.3.

In one embodiment, in the middle layer of the inner belt of the present application, the weight ratio of low-density polyethylene and linear low-density polyethylene is 1:5 to 5:1, preferably 1:2 to 2:1, more preferably 1.5 :1.

As mentioned above, the inner belt has a special seven-layer structure, a specific barrier layer, a sealant layer structure, and the chemical composition of the outer layer and the middle layer is variable to adjust the adhesion between the layers in the inner belt, so it can provide this Significant technical effects of the invention.

In one embodiment, the bonding resin (adhesive) used to laminate the barrier layer and the intermediate layer of the inner belt as described above is, for example, ethylene-vinyl acetate copolymer, or by ethylene-vinyl methacrylate Ion-bonded polymers prepared with metal ion crosslinking molecules in copolymers, ethylene methacrylic acid copolymers, ethylene acrylate rubbers, ethylene-vinyl acetate copolymers, liquid rubber modified adhesives, polyurethane modified adhesives Glue, elastic microsphere high-strength adhesive glue, modified nanoparticle adhesive glue and one of the substances obtained by modifying any of the above substances, or any combination thereof.

These adhesive resins have more functional groups introduced by the grafting reaction. The rich functional groups can be compatible with the intermediate layer adjacent to the base resin, increase the bonding force with the intermediate layer, and prevent the film from peeling off during the tearing process and film residue. Or drawing and poor appearance of the peeled surface.

Preferably, the adhesive resin (adhesive) that is suitable for the above-mentioned conditions is selected from anhydride-modified linear low-density polyethylene (LLDPE) resin, elastic microsphere high-strength adhesive, and modified nanoparticle adhesive and One of the substances obtained by modifying any of the above substances or any combination thereof; more preferably, the adhesive resin is a modified nanoparticle adhesive.

Preferably, the modified nanoparticle adhesive is a hyperbranched nano-modified polyurethane adhesive (CPUAD) with a specific structure, which is prepared by the following steps:

(1) Weigh the tribasic acid and dibasic alcohol into the reactor according to the acid-alcohol molar ratio 1: (1.0～1.2), raise the temperature to 140°C, add the catalyst accounting for 2‰ of the total mass of the reaction system, and put it under the condition of nitrogen protection Stir down;

The structure of the tribasic acid is as follows:

Described glycol is propylene glycol;

(2) When the fractional distillation temperature at the top of the tower is less than 80°C, start to gradually heat up to the reaction temperature of 210°C, and keep it warm for 2 to 3 hours under nitrogen protection;

(3) At a reaction temperature of 210°C, gradually vacuumize from low to high until the acid value of the product is less than 1mg KOH/g to obtain qualified polyester;

(4) Weigh the required number of parts of the vacuum dehydrated polyester into the reactor, and raise the temperature to 80°C;

(5) Add the required number of chain extenders after distillation and dehydration, and mix well;

(6) Add the required amount of isocyanate, stir rapidly, and gradually add the mixed solvent when the stirring is difficult;

(7) Add the required number of catalysts and stir for 1 hour at 60-80°C;

(8) Add the required number of dried nano-silica and silane coupling agent, and stir at 60-80°C for 1 hour;

(9) Add the required number of polymerization inhibitors and stir for 10 minutes;

(10) After inspection, put it into the rubber hose to make the finished product.

When the above-mentioned isocyanate is a solid aromatic isocyanate, it needs to be melted in hot water at 60-80°C before adding.

A second aspect of the invention relates to a method of manufacturing an inner band comprising the steps of:

Coextrude the following ingredients in the order described below: LDPE and LLDPE blend; LDPE and LLDPE blend; binder; ethylene vinyl alcohol copolymer ; adhesives; low density polyethylene and linear low density polyethylene blends; low density polyethylene and linear low density polyethylene blends;

An inner belt is obtained which is a laminate comprising: an outer layer made of a blend of low density polyethylene and linear low density polyethylene; an intermediate layer made of a blend of low density polyethylene and linear low density polyethylene layer; an adhesive layer; an ethylene-vinyl alcohol copolymer barrier layer; another adhesive layer; another intermediate layer prepared by blending low density polyethylene and linear low density polyethylene; Another outer layer made from a linear low density polyethylene blend, these layers were laminated in the order described above. The raw materials used in the above method are all commonly used raw materials, without special requirements, and each step of lamination can be carried out under basically the same process conditions, and there is no special requirement for equipment.

A third aspect of the present invention also relates to a packaging container using an inner tape as claimed in claim 1 .

The present invention will be described in detail below with reference to several examples.

[Example 1]

The layers used to prepare the inner belt are: the weight ratio of low-density polyethylene (melt index 2.0, density 0.924g/cm ³ ) to linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) is 1/5 Outer layer of blend, middle layer with a weight ratio of 5/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (anhydride-modified linear low density polyethylene resin), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (anhydride-modified Another adhesive layer of linear low density polyethylene resin), low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) Another outer layer of a blend of 1/5 by weight, low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) by weight Another intermediate layer with a ratio of 5/1.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns) layered structure.

[Example 2]

The layers used to prepare the inner belt are: the weight ratio of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) is 1/2 Outer layer of blend, middle layer with a weight ratio of 2/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (anhydride-modified linear low density polyethylene resin), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (anhydride-modified Another adhesive layer of linear low density polyethylene resin), low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) Another outer layer of 1/2 blend by weight, low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) weight Another intermediate layer with a ratio of 2/1.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Example 3]

The layers used to prepare the inner belt are: low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) with a weight ratio of 1/1.3 Outer layer of blend, middle layer with a weight ratio of 1.5/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (anhydride-modified linear low density polyethylene resin), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (anhydride-modified Another adhesive layer of linear low density polyethylene resin), low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) Another outer layer of a blend of 1/1.3 weight ratio, low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) weight Another intermediate layer with a ratio of 1.5/1.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Example 4]

The layers used to prepare the inner belt are: low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) with a weight ratio of 1/1.3 Outer layer of blend, middle layer with a weight ratio of 1.5/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (elastic microsphere high-strength adhesive glue), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (elastic microsphere high-strength adhesive) Adhesive glue), another adhesive layer of low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) weight ratio is 1 The other outer layer of /1.3 blend, low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) weight ratio is 1.5/ 1 another middle layer.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Example 5]

The layers used to prepare the inner belt are: low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) with a weight ratio of 1/1.3 Outer layer of blend, middle layer with a weight ratio of 1.5/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (modified nanoparticle adhesive glue), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (modified nanoparticle adhesive Adhesive) another adhesive layer, low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) weight ratio is 1/1.3 The other outer layer of the blend, low-density polyethylene (melt index 2.0, density 0.924g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918g/cm ³ ) weight ratio is 1.5/1 Another middle layer.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Example 6]

The layers used to prepare the inner belt are: low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) with a weight ratio of 1/1.3 Outer layer of blend, middle layer with a weight ratio of 1.5/1 low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , adhesive layer including adhesive (Ad) (CPUAD), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), another adhesive layer including adhesive (Ad) (CPUAD), low density Another outer layer of a blend of polyethylene (melt index 2.0, density 0.924 g/cm ³ ) and linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) in a weight ratio of 1/1.3, low density polyethylene Another intermediate layer with a weight ratio of ethylene (melt index 2.0, density 0.924 g/cm ³ ) to linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) of 1.5/1.

Heating and melting the resin as described above, the molten resin is copolymerized according to LDPE and LLDPE blend/LDPE and LLDPE blend/adhesive/ethylene vinyl alcohol The sequence of material/adhesive layer/low density polyethylene and linear low density polyethylene blend/low density polyethylene and linear low density polyethylene blend is filled into a co-extrusion die and molded into a film . The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Comparative Example 1]

The layers used to prepare the inner belt are: the outer layer of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), the middle layer of linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , an adhesive layer comprising an adhesive (Ad) (anhydride-modified linear low-density polyethylene resin), a barrier layer of ethylene-vinyl alcohol copolymer (EVOH), comprising an adhesive (Ad) (anhydride-modified Another adhesive layer of linear low density polyethylene resin), another outer layer of low density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), linear low density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) another intermediate layer.

Heating and melting the resin as above, the molten resin is in accordance with linear low density polyethylene/low density polyethylene/adhesive/ethylene-vinyl alcohol copolymer/adhesive layer/low density polyethylene/linear low density polyethylene The sequence is filled into the co-extrusion die and molded into a film. The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Comparative example 2]

The layers used to prepare the inner belt are: the outer layer of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), the middle layer of linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (elastic microsphere high-strength adhesive glue), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (elastic microsphere high-strength adhesive) adhesive glue), another outer layer of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) another intermediate layer.

Heating and melting the resin as above, the molten resin is in accordance with linear low density polyethylene/low density polyethylene/adhesive/ethylene-vinyl alcohol copolymer/adhesive layer/low density polyethylene/linear low density polyethylene The sequence is filled into the co-extrusion die and molded into a film. The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

[Comparative example 3]

The layers used to prepare the inner belt are: the outer layer of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), the middle layer of linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) , Adhesive layer including adhesive (Ad) (modified nanoparticle adhesive glue), barrier layer of ethylene-vinyl alcohol copolymer (EVOH), including adhesive (Ad) (modified nanoparticle adhesive glue), another outer layer of low-density polyethylene (melt index 2.0, density 0.924 g/cm ³ ), another outer layer of linear low-density polyethylene (melt index 2.0, density 0.918 g/cm ³ ) Another middle layer.

Heating and melting the resin as above, the molten resin is in accordance with linear low density polyethylene/low density polyethylene/adhesive/ethylene-vinyl alcohol copolymer/adhesive layer/low density polyethylene/linear low density polyethylene The sequence is filled into the co-extrusion die and molded into a film. The molded multilayer film has the characteristics of LLDPE (layer thickness of 5 microns)/LDPE (layer thickness of 10 microns)/Ad (layer thickness of 6 microns)/EVOH (layer thickness of 8 microns)/Ad (layer thickness of 6 microns)/LDPE (layer thickness 10 microns)/LLDPE (layer thickness 5 microns).

test methods

Various types of inner tapes can be obtained from the multilayer films obtained in the above examples. Using these various types of inner tapes, the lower surface of the opening portion sealed with the pull tab of the paper container as shown in FIG. 2 is sealed along the outer periphery, thereby sealing the opening portion from the lower side. When the pull tab of the paper container using the inner tape in the above example is pulled to unseal the opening, it is visually observed how the inner tape is broken at a portion near the edge portion of the opening. When the pull tab is peeled off, the inner tape is cut quickly, the tape does not extend in the area near the edge of the opening, and no part of the tape leaves fibers or small pieces, the test is passed. Conversely, if the inner tape extends near the edge of the opening and the inner tape is broken, leaving fibers and small pieces in a part of the inner tape, the test fails.

100 samples were taken from each inner band, and the number of qualified samples was determined. The results are shown in Table 1.

Table 1 sample Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative example 1 Comparative example 2 Comparative example 3 qualified 75 80 90 87 92 98 67 55 69 unqualified 25 20 10 13 8 2 33 45 31

The test results show that the inner bands manufactured in Examples 1, 2, 3, 4, 5 and 6 provide a good yield of qualified products, especially the yields of Examples 3, 5 and 6 all reach more than 90%. In contrast, the yields of the inner belts produced in Comparative Examples were not satisfactory.

The foregoing examples are illustrative only, used to explain some of the features of the present disclosure. The appended claims are intended to claim the broadest scope conceivable and the embodiments presented herein are merely illustrations of selected implementations according to all possible combinations of embodiments. Accordingly, it is the applicant's intention that the appended claims not be limited by the selection of examples which characterize the invention. Moreover, advances in science and technology will create possible equivalents or sub-replacements not presently considered due to inaccuracies of language, and these changes should also be construed to be covered by the appended claims where possible .

Claims (6)

1. the interior band of a kind of packing container, including：Outer by Low Density Polyethylene and the preparation of linear low density polyethylene blend Layer；Intermediate layer by Low Density Polyethylene and the preparation of linear low density polyethylene blend；Adhesive phase；Ethylene-vinyl alcohol is altogether Polymers barrier layer；Another adhesive phase；Another centre by Low Density Polyethylene and the preparation of linear low density polyethylene blend Layer；And another outer layer by Low Density Polyethylene and the preparation of linear low density polyethylene blend, these layers are according to above-mentioned suitable Sequence is laminated；

In wherein said outer layer and another outer layer, the weight of Low Density Polyethylene and linear low density polyethylene is than for 1:1.3；

In wherein said intermediate layer and another intermediate layer, the weight of Low Density Polyethylene and linear low density polyethylene is than for 1.5: 1.

2. the interior band of packing container as claimed in claim 1, wherein said adhesive phase and another adhesive phase are by binding agent Make, described adhesive is ethylene-vinyl acetate copolymer, by using gold in ethylene-methyl methacrylate vinyl copolymer Belong to ionomer molecule preparation containing iolon, ethylene methacrylic acid copolymer, ethylene-acrylate rubber, liquid Modified rubber adhesive glue, polyurethane-modified adhesive glue, anhydride modified linear low density polyethylene (LLDPE) resin, elasticity is micro- Ball high-strength adhesive glue, and modified Nano bind particles glue and by one of material of modified any of the above-described material gained Or its combination in any.

3. the interior band of packing container as claimed in claim 2, wherein said adhesive phase and another adhesive phase are by binding agent Make, described adhesive is anhydride modified linear low density polyethylene (LLDPE) resin, elastic microsphere high-strength adhesive glue, And one of modified Nano bind particles glue and the material by modified any of the above-described material gained or its combination in any.

4. the interior band of packing container as claimed in claim 1, the thickness of wherein each tunic is：1～9 micron of outer layer；Intermediate layer 3 ～18 microns；2～10 microns of adhesive phase；3～12 microns of barrier layer；3～18 microns of another intermediate layer；Another outer layer 1～9 is micro- Rice.

5. a kind of manufacture packing container as claimed in claim 1 method of interior band, comprises the following steps：

According to the coextrusion following component of order as described below：Low Density Polyethylene and linear low density polyethylene blend；Low Density polyethylene and linear low density polyethylene blend；Binding agent；Ethylene-vinyl alcohol copolymer；Binding agent；Low density polyethylene Alkene and linear low density polyethylene blend；Low Density Polyethylene and linear low density polyethylene blend；And

Band in obtaining, described interior band is layered product, including：Prepared by Low Density Polyethylene and linear low density polyethylene blending Outer layer；Intermediate layer by Low Density Polyethylene and the preparation of linear low density polyethylene blend；Adhesive phase；Ethylene-vinyl alcohol Copolymer barrier layer；Another adhesive phase；Another centre by Low Density Polyethylene and linear low density polyethylene blending preparation Layer；And another outer layer by Low Density Polyethylene and the preparation of linear low density polyethylene blend, these layers are according to above-mentioned suitable Sequence is laminated.

6. a kind of packing container using interior band as claimed in claim 1.