JPH09141791A - Multilayer film and packaging body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make an easy opening property, impact resistance, stress cracking resistance improve by laminating a specified non-oriented easy tearing film as an intermediate layer between a polyethylene type sealant film containing specified quantity of linear low density polyethylene and a biaxially oriented nylon film. SOLUTION: A polyethylene type sealant film A containing at least 10wt.% of liner low density polyethylene, a non-oriented easy tearing film B containing a non-compatible polymer blend as a main component, and a biaxially oriented nylon film C are laminated integrally with the film B as an intermediate layer. In the polymer blend for the film B, 0.5-30 pts.wt. of a compatibility improver is added into 100 pts.wt. of a resin constituting a continuous layer and a dispersion layer. The film B is formed from a non-miscible polymer blend in which a dispersion layer is a styrene resin containing at least 10wt.% of a styrene unit.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouch-type packaging body such as a detergent pouch for refilling, and more specifically, an easily openable pouch-type packaging body having excellent impact resistance and stress cracking resistance. It relates to a multilayer film for producing it.

[0002]

2. Description of the Related Art In recent years, the biggest problem in packaging materials is the problem of waste and resource saving. While needs for recyclability, refillability, incineration, etc. are rapidly increasing, the move toward pouches from large cans and bottles to plastic bottles or pouches, and plastic bottles to pouches, will continue to become stronger. Is expected to be.

Also in the detergent field, it is becoming more and more common to supply a refill detergent in a pouch type package and repeatedly use a plastic bottle container. Examples of the pouch type packaging material in this case include Natera (product of Lion Corporation) and Moa (product of Kao Corporation).
Packaging materials used for refilling liquid detergent pouches such as JP-A-5-193079 and JP-A-5-24
Some are disclosed in Japanese Patent No. 5990. Such a bag is made of a multilayer film, and the general structure of the multilayer film is that the innermost layer in contact with the liquid detergent is a linear low-density polyethylene-based sealant film, and the intermediate layer is a stretched polyolefin-based film. Examples of commercially available films of this type include Valilla of Nippon Petrochemical Co., Ltd., Lupic of Tonen Petrochemical Co., Ltd., Hibron of Mitsui Toatsu Chemical Co., Ltd., and Tokyo Cellophane Co., Ltd.
O-PE manufactured by Toyo Kagaku Co., Ltd., Karariyan Y manufactured by Toyo Kagaku Co., Ltd., Tamai Eagle manufactured by Tama Poly Co., Ltd.
8349, Japanese Patent Laid-Open No. 2-242764, Japanese Patent Laid-Open No. 2-258.
342 and the like. Furthermore, a biaxially stretched nylon film is used for the outermost layer.

[0004]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Pouches for refill detergents are important performance requirements such as ease of refill of detergent,
It is stable during the distribution period, and is easy and costly to manufacture in the pouch manufacturing process.

First, the ease of refilling will be described. A bag-like package such as a standing pouch made by heat-sealing a laminated film is generally used, but a stretched film and an excellent impact resistance are excellent because of its strength. A linear low-density polyethylene-based sealant film is used.
The linear low-density polyethylene-based sealant film has a rubber-like tackiness, and even if this film alone is torn, it cannot be torn well. When a notch is formed in the stretched film, it can be easily torn from the notch, but it is not torn in the intended direction, but is torn in various directions by itself, and the bag often cannot be opened successfully. It is presumed that this is due to a difference in the stretching ratio between the length and width of the stretched film, a slight deviation in the stretching ratio between the center portion in the film width direction and the end portion in the width direction, and the like.

In addition, the stretched film has a high molecular orientation, which facilitates the promotion of crystallization, which reduces the impact energy absorption / relaxation. In addition, since drawing equipment and processes are required, it is difficult to avoid an increase in production cost, and also in terms of product quality, from the above reason,
Especially in a wide product, stretch unevenness is likely to occur, which causes tearing unevenness when the pouch manufactured from this is opened.

Next, regarding the stability during the distribution period, there is sufficient impact resistance and strength that the pouch does not break during handling.
It is necessary to have environmental stress cracking resistance so that stress cracking does not occur due to the influence of the storage environment and liquid leakage does not occur.

The inventors of the present invention have developed a multi-layer film for the purpose of developing a pouch type package having a simple manufacturing process and excellent quality in terms of easy opening, impact resistance and stress cracking resistance. As a result of earnestly researching the constitution, the inventor of the present invention, which was invented by joint research in advance, disclosed the easily tearable film (JP-A-6-220220) as an intermediate layer of the multilayer film without stretching. By applying it as it is, a multi-layer film having a technical idea basically different from that of the conventional structure has been developed, and the present invention has been completed.

[0009]

A polyethylene-based sealant film (a) containing at least 10% by weight of linear low-density polyethylene, a non-stretch easily tearable film (b) mainly composed of an incompatible polymer blend, and A multilayer film for producing an easily-openable pouch type package, comprising a nylon biaxially stretched film (c) integrally laminated with the film (b) as an intermediate layer.

The multilayer film according to claim 1, wherein the film (b) is formed from an incompatible polymer blend having a continuous phase / dispersed phase weight ratio of 35-98 / 65-2. The compatibilizer is added in an amount of 0.5 to 30 parts by weight to 100 parts by weight of the total of the constituent resins of the continuous phase and the dispersed phase as the polymer blend for forming the film (b).
The multilayer film according to. The multilayer film according to claim 1 or 3, wherein the film (b) is formed from an incompatible polymer blend containing a styrene resin having a styrene content of 10% by weight or more as a dispersed phase.

The multilayer film according to claim 1 or 3, wherein the film (b) is formed from an incompatible polymer blend containing a polyamide resin as a dispersed phase. The multilayer film according to claim 1, wherein the film (b) is formed from an incompatible polymer blend containing a saturated polyester resin as a dispersed phase.

The film (b) contains a polypropylene resin or a polyethylene resin as a continuous phase styrene content of 10% by weight.
The multilayer film according to claim 1 or 4, which is formed from a polymer blend containing the styrene resin as a dispersed phase and a hydrogenated product of a vinyl aromatic-conjugated diene block copolymer as a compatibilizing agent. . The interfacial adhesion strength between the film (b) and the film (a) or the film (c) is 1
20 g / 15 mm or more, characterized in that
And the multilayer film according to any one of 1 to 7.

The bag-shaped product obtained by sealing the multilayer film according to any one of claims 1 to 8 with the film (a) as the innermost layer is filled with an object to be packaged, and then the opening is sealed. Easy to open pouch type package. The easily openable pouch type package according to claim 9, wherein the article to be packaged is a refill detergent. The present invention proposes the above.

The sealant film (a) constituting the multilayer film of the present invention is a polyethylene composition film containing at least 10% by weight of linear low density polyethylene. The linear low-density polyethylene used in the present invention (hereinafter L
LDPE) is, for example, Sumikasen-L (Sumitomo Chemical Co., Ltd.), Mitsubishi Polyethyl-LL (Mitsubishi Petrochemical Co., Ltd., Mitsubishi Kasei Co., Ltd.), Ultozex (Mitsui Petrochemical Co., Ltd.), Sho Elex Linear (Showa Denko KK),
Those sold under the trademark of Moretec (Idemitsu Petrochemical Co., Ltd.) can be used. As the sealant film molding resin used in the present invention, those having a melt flow rate (abbreviated as MFR) (190 ° C., 2.16 kg load) of 13 g / 10 minutes or less are preferably used, and more preferably, MFR is 5 g / Those of 10 minutes or less are used. Other resin components contained in the polyethylene composition film include low-density polyethylene (abbreviated as LDPE), ethylene-propylene copolymer, ethylene-butene 1 copolymer, propylene-butene 1 copolymer, ethylene-propylene-butene. One copolymer or the like can be used. Examples of LDPE include Sumikasen (Sumitomo Chemical Co., Ltd.), and examples of ethylene-propylene copolymer include JSR-EP (Japan Synthetic Rubber Co., Ltd.) and Tufmer X.
R series (Mitsui Petrochemical Co., Ltd.), ethylene-butene 1 copolymer as Tuffmer A series (Mitsui Petrochemical Co., Ltd.), and propylene-butene 1 copolymer as Tuffmer P series (Mitsui Petrochemical ( Ltd.), ethylene-
As the propylene-butene 1 copolymer, Tuffmer RS series (Mitsui Petrochemical Co., Ltd.) or the like can be used. The resin that can be used as the other resin component contained in the polyethylene composition film is not limited to the above, and any polyolefin-based elastomer can be used. Additives such as lubricants and anti-blocking agents can be added as necessary. Thickness is 30 to 3
Generally, the thickness is 00 μm, but the thickness is preferably 60 to 200 μm, more preferably 80 to 160 μm.
Is used.

Since LLDPE is tough and cracks hardly propagate, it is excellent in impact resistance but inferior in openability.
LDPE has excellent openability but poor stress cracking resistance. The ethylene-propylene copolymer has no problem in opening property and stress cracking resistance, but has poor heat resistance. In the present invention, those used in bags of liquid detergent for refill sold under the trademarks of Natella of Lion Co., Ltd. and Moa of Kao Corp. are used.

The present invention is characterized by the intermediate layer. The easily tearable film (b) constituting the intermediate layer is described in JP-A-6-22.
It is described in detail in Japanese Patent No. 0220. Among these, those particularly suitable for the multilayer film of the present invention are exemplified. Polypropylene, high-density polyethylene (abbreviated as HDPE), and LLDPE are preferably used as the resin forming the continuous phase of the incompatible polymer blend used for forming the film (b). In addition, these blends and LDPE, an ethylene-propylene copolymer, an ethylene-butene 1 copolymer, a propylene-butene 1 copolymer, an ethylene-propylene-butene 1 copolymer, and the like are added to these blends.
Blends of up to 30% by weight can also be used.

Examples of polypropylene include Noblene (Sumitomo Chemical Co., Ltd., Mitsui Toatsu Chemical Co., Ltd.), UB
What is marketed as E polypro (Ube Industries, Ltd.), Mitsubishi polybro (Mitsubishi Petrochemical Co., Ltd., Mitsubishi Kasei Co., Ltd.) Hypol (Mitsui Petrochemical Co., Ltd.) can be used. These are common isotactic polypropylenes, but they may be homopolymers of H propylene or copolymers with comonomers such as ethylene and putene 1. The copolymer may be a random copolymer or a block copolymer. In the case of random copolymerization, the comonomer ratio is preferably 10% by weight or less, and in the case of block copolymerization, it is preferably 20% by weight or less.

Next, as the resin forming the dispersed phase, polystyrene (abbreviated to PS, general polystyrene-GPPS impact polystyrene-HIPS is included), polystyrene terephthalate resin (abbreviated to PBT), nylon resin (abbreviated to Ny, 6, 66, 11, 12, MXD6, Novamid X21, Sealer PA) and the like are preferably used.

The ratio of the continuous phase to the dispersed phase is continuous phase / dispersed phase = 35 to 98/65 to 2% by weight. Preferably, 5
It is 0 to 95/50 to 5% by weight. Furthermore, it is preferably 60 to 90/40 to 10% by weight. The compatibilizer is included in an amount of 0.5 to 30 parts by weight based on 100 parts by weight of the resin forming the continuous phase and the dispersed phase. The compatibilizer for each combination is described in detail in JP-A-6-220220.

The preferred continuous phase forming resin and dispersed phase forming resin are a combination of polypropylene and polystyrene. As the compatibilizer added at this time, a hydrogenated styrene monomer-conjugated diene copolymer or the like is preferably used.

The film (b) generally has a thickness of 10 to 50 μm.
m is used, but preferably 15 to 30 μm
It is. In order to mold such a thin film,
The melt viscosity ratio of the continuous phase polypropylene and the dispersed phase polystyrene is preferably a specific ratio. When the melt viscosity is expressed using MFR (250 ° C., 2.16 kg load), dispersed phase / continuous phase = 4 or less, preferably 2 or less, more preferably 1.2 or less. The MFR of continuous phase polypropylene is 0.1 to 20 g / 10.
Min, preferably 0.7 to 15 g / 10 min. The MFR of the dispersed phase polystyrene is 0.1 to 40 g / 10 minutes,
It is preferably 0.7 to 20 g / 10 minutes.

In order for the intermediate layer-constituting film (b) to have a surface property capable of being laminated on the film (a) and the film (c) with an interfacial adhesive strength of 120 g / 15 mm or more required for the package of the present invention. The dispersed phase / continuous phase ratio is 2 or less, preferably 1.2 or less, more preferably 0.8 or less. Then, the resin 10 forming the continuous phase and the dispersed phase
It is further improved by adding 0.5 to 30 parts by weight of the compatibilizing agent to 0 parts by weight. More preferable addition amount is 1.
5 to 15 parts by weight. If the amount is too small, it is not effective. If the amount is too large, it may cause deterioration of the physical properties of the film such as strength and waist, and may cause fish eyes. A preferred compatibilizing agent is a hydrogenated styrene monomer-conjugated diene copolymer having a styrene content of 10 to 80% by weight,
It is preferably 15 to 60% by weight, and the others preferably have a skeleton of an olefin polymer such as ethylene, propylene and butene. The styrene skeleton and the other skeleton may be randomly copolymerized or may be copolymerized into blocks. Preferably, the copolymerized block is more effective. The skeleton may have a straight chain or a branched chain.

Further, the film (C) will be described. The film (C) is a biaxially stretched nylon film. A common film is Ny6 film. For example, Idemitsu Petrochemical Co., Ltd., Unilon, Unitika Ltd.
Emblem, Bonil of Kojin Co., Ltd., Toyobo Co., Ltd.
Baden and Mitsubishi Kasei Polytech Co., Ltd. Santonir and others are sold under the trademark. Films of other nylons or blends of two or more nylons may be used. For example, there is a uniathlon film of Idemitsu Petrochemical Co., Ltd., which is also a blend film of nylon 6 and MXD6 nylon (aromatic nylon of Mitsubishi Gas Chemical Co., Inc.). The uniathlon film not only has sufficient strength required for a biaxially stretched film, but also has a certain degree of tearability to MD. Therefore, when used in the pouch of the present invention, the It works to assist the tearing property of the film, and the tearing feeling when opening is further improved. Generally, the thickness is 10 to 30 μm, but a thickness of 15 μm is often used.

The easily openable pouch type package of the present invention comprises:
Not limited to detergents, it is useful as a package for various types of packaged items such as drinking water, foods, chemicals, medicines, chemical products and the like. A publicly known laminating method such as an extrusion coating method, a hot lamination method and a dry lamination method can be applied to the production of the multilayer film of the present invention. Further, as a method for producing from this multilayer film, a heat sealing method such as a bar seal, a rotating roll seal, a belt seal, a sliding nip seal, an impulse sealing method, a high frequency sealing method by induction heating or dielectric heating, and an ultrasonic sealing method. Known methods such as the above can be applied. Furthermore, in addition to filling and sealing machine for pouch,
A batch type vacuum packaging machine, a rotary filling vacuum packaging machine, etc. can be used. The features of the present invention will be specifically described below with reference to Examples, but the technical scope of the present invention is not limited thereto.

[0025]

【Example】

 Examples 1 to 11 1) Production of multilayer film 1) -1 Table 1 shows the details of the constituent films.

[0026]

[Table 1] 1) -2 Laminating

2) Fabrication of refill detergent pouch A standing pouch having a length of 255 mm, a width of 115 mm, and a bottom forming fold of 35 mm having the film (c) as the innermost layer is heat-sealed by bar sealing from each of the above-mentioned multilayer films. After preparing, and then filling 500 ml of liquid detergent NATERA (product of Lion Corporation), the opening was closed by heat sealing with a bar seal to manufacture a refill detergent pouch.

3) Evaluation Method for Prototype Pouch 3) -1 Openability (Part 1) V is added to one end of the upper part of the test pouch.
The easiness of tearing with a notch in the lateral direction by the hand was judged according to the following criteria. B) It tears linearly with a small opening force. ○ (Good) Intermediate between b) a) and c) △ c) Does not tear linearly and / or requires a large opening force. × (Poor) 3) -2 Openability (Part 2) The ease of tearing when a pouch without a notch was torn in the lateral direction was judged according to the following criteria. B) It can be torn. ○ (Good) B) It can be torn, but requires a large amount of force. △ C) There is almost no tearing. X (Poor) 3) -3 Stress crack resistance The presence or absence of cracks when the test pouch was stored at 60 ° C for 7 days was examined and judged according to the following criteria. B) No liquid leakage is observed. ○ (Good) B) Liquid leakage is observed. × (Poor) 3) -4 Impact resistance (single drop strength) Each of the 50 prototype pouches was dropped from a height of 1.0 m onto concrete by a vertical drop method, tested, and judged according to the following criteria. B) There were no broken bags in all 50 bags. ○ (Good) B) Within 5 bags were broken. C) There were 6 or more broken bags. × (defective)

[0029]

[Comparative example]

Comparative Examples 1 to 3 For refilling in the same manner as in Examples 1 to 6 and 8 to 11, except that the commercially available stretched film shown in Table 2 was used instead of the non-stretch easily tearable film (b). A detergent pouch was prepared and evaluated.

Comparative Examples 4 and 5 Commercially available refill detergent pouches (product of Company A, product of Company B) were evaluated in the same manner as in Examples.

Comparative Examples 6 to 8 If the disperse phase is further lacked (Comparative Example 8) and no compatibilizer is added, the refill detergent pouches are produced in the same manner as in Examples 1 to 6 and 8 to 10. And evaluated. Table 2 shows the above results.

[0032]

[Table 2]

Details of each component of the intermediate layer film are as follows. The numerical values shown in the table are% by weight. PP (1) Ube Polypro FM101A Ube Industries, Ltd.
Product PP (2) Ube Polypro YK121 Ube Industries, Ltd.
Product HDPE (1) Mitsubishi Polyethylene J20S Mitsubishi Kasei Co., Ltd. Product HDPE (2) Hi-Zex 3300F Mitsui Petrochemical Co., Ltd. product LLDPE (1) Sumikasen FA203-1 Sumitomo Chemical Co., Ltd. Product PS (1) Daicel Styrol 51 Daicel Chemical Products PS (2) Styron 683 Asahi Kasei Product PS (3) Daicel Styrol 20 Daicel Chemical Co., Ltd. Product Ny 6 (1) Ube Nylon 1030B18 Ube Industries Co., Ltd. Product PBT (1) Duranex 800FP Polyplastics Product SEBS (1) Clayton G1652 Shell Chemical Co., Ltd. Product SEBS (2) Tuftex H1051 Asahi Kasei Product SEBS (3) Tuftex H1061 Asahi Kasei Product SEPS (1) Septon 2023 Kuraray Co., Ltd. Made C (N) Novatec AP197P Mitsubishi Kasei Co., Ltd. Product C (R) multiplex Pearl RA3150 Oil & Chemical Co., Ltd.
Products Commercially-stretched film (X) Ballyra HG film Thickness 25 μm Nisseki Chemical Co., Ltd. Products Commercially-stretched film (Y) Barilla PG film Thickness 25 μm Nisseki Chemical Co., Ltd. Products Commercially-stretched film (Z) Kalaryan Y-film Thickness 25 μm Toyo Kagaku Products Co., Ltd.

[0034]

As described above, the pouch-type package of the present invention has the following structure in the multilayer film,
Since the easy-to-draw film made of the incompatible polymer blend is provided as the intermediate layer, heat shrinkage and wrinkling hardly occur during the sealing process. In addition, compared with the conventional components, the package is remarkably excellent in unsealing property and impact resistance, and also has good stress cracking resistance. The multilayer film according to the present invention and the pouch-type package manufactured from the same exhibit excellent effects, especially when applied to a refill detergent pouch, but are also used for items to be packaged other than the detergent. be able to.

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Claims (10)

[Claims] 1. At least one linear low density polyethylene
The polyethylene-based sealant film (a) containing 0% by weight, the non-stretch easily tearable film (b) containing the incompatible polymer blend as a main material, and the nylon-based biaxially stretched film (c) are the same as the film (b). A multilayer film for producing an easily-openable pouch type package, which is integrally laminated as an intermediate layer. 2. The multilayer film according to claim 1, wherein the film (b) is formed from an incompatible polymer blend having a weight ratio of continuous phase / dispersed phase of 35 to 98 / 65-2. 3. A polymer blend for forming film (b), wherein 0.5 to 30 parts by weight of a compatibilizer is added to 100 parts by weight of a total of constituent resins of a continuous phase and a dispersed phase. 2. The multilayer film according to 2. 4. The multilayer film according to claim 1 or 3, wherein the film (b) is formed from an incompatible polymer blend containing a styrene resin having a styrene content of 10% by weight or more as a dispersed phase. 5. The multilayer film according to claim 1, wherein the film (b) is formed from an incompatible polymer blend having a polyamide resin as a dispersed phase. 6. The multilayer film according to claim 1, wherein the film (b) is formed from an incompatible polymer blend containing a saturated polyester resin as a dispersed phase. 7. The film (b) comprises a polypropylene resin or a polyethylene resin as a continuous phase, a dispersed phase of a styrene resin having a styrene content of 10% by weight or more, and a water of a vinyl aromatic-conjugated diene block copolymer. The multilayer film according to claim 1 or 4, which is formed from a polymer blend containing an additive as a compatibilizer. 8. The interface adhesion strength between the film (b) and the film (a) or the film (c) is 120 g / 15 mm.
It is above, The multilayer film of Claim 1 or 7 characterized by the above-mentioned. 9. A bag-shaped product obtained by sealing the multilayer film according to any one of claims 1 to 8 with the film (a) as the innermost layer and filling the object to be packaged, and then sealing the opening. Easy-to-open pouch type package. 10. The easily openable pouch type package according to claim 9, wherein the article to be packaged is a refill detergent.