JPH06305096A - Packing material excellent in heat resistance and strength and having linear cutting properties - Google Patents

Abstract

PURPOSE:To develop a packing material having high thrusting resistance, high strength, moistureproof properties and aroma retaining properties, capable of being easily linearly cut, sultablly usable in the packing of rice cake, confectionary, flakes of dried bonito, mayonnaise, ketchup, soup, mastard, miso or pickles and capable of being continuously and inexpensively produced. CONSTITUTION:A packing material excellent in heat resistance and strength having linear cutting properties is composed of a laminate containing a moistureproof film layer (a) obtained by uniaxially rolling a film based on a high density polyethylene resin and characterized by that the degree of orientation of longitudinal and lateral axis directions measured by an infrared two-color method is 5 or more, a polyamide resin film (b) and a resin film layer (c) having barrier properties composed of a barrier resin other than a polyamide resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a straight-cut packaging material having excellent heat resistance and strength, and more specifically, packaging of rice cake packaging, confectionery packaging, shaving bags, mayonnaise, ketchup, soup, mustard, miso, pickles, etc. The present invention relates to a linear-cutting packaging material which has excellent puncture resistance and strength, moisture resistance and aroma retention and is excellent in heat resistance and strength that can be easily cut linearly by hand.

[0002]

2. Description of the Related Art Conventionally, uniaxially stretched or biaxially stretched films have been used as packaging materials such as confectionery packaging and shaving bags, which are required to have moisture resistance and aroma retention, but have sufficient straight line cutting properties. However, it has the drawback that the cut line runs diagonally. When an excessive force is applied to the film when cutting such a packaging material, a problem such as the contents popping out from the cut in an unexpected direction occurs. Further, in such a packaging bag, a cut line for opening (parallel to Japanese Utility Model Laid-Open No. 57-80462) and a notch (open to Japanese Utility Model Laid-Open No. 58-169044, Japanese Patent Laid-Open No. 58-156656) are provided in parallel with the heat-sealing line. Although the one with is provided, it is still poor in linear cutability.

[0003]

DISCLOSURE OF THE INVENTION The object of the present invention is to have high puncture resistance and strength, moisture resistance and aroma retention, and
It is a packaging material that can be easily cut linearly by hand and is excellent in heat resistance and strength suitable for rice cake packaging, confectionery packaging, shaving bags, mayonnaise, ketchup, soup, mustard, miso, pickles, etc. It is to provide a sex packaging material.

[0004]

The invention according to claim 1 of the present invention is as follows.
(A) The orientation degree ratio in the vertical axis (MD) direction and the horizontal axis (TD) direction, which is measured by an infrared dichroic method obtained by uniaxially rolling a film containing a high-density polyethylene resin as a main component, is 5 or more. A straight cut having excellent heat resistance and strength, which is characterized by comprising a laminate including a moisture-proof film layer, (b) a polyamide resin film layer, and (c) a barrier resin film layer made of a barrier resin other than the polyamide resin. It is a packaging material.

According to the invention of claim 2 of the present invention, the linear cuttability (X) is in the range of 0.8≤X≤1.2. It is an excellent linear cut packaging material.

The present invention will be described in detail below. The resin used for the film containing the high-density polyethylene resin of the present invention as a main component means an ethylene homopolymer having a density in the range of 0.94 to 0.97 g / cm ³ , ethylene and propylene, butene-1,4-methyl. Mainly composed of a copolymer with other α-olefins such as lupentene-1 and hexene-1 and a mixture thereof, polypropylene, density 0.94 g /
You may mix medium density polyethylene, low density polyethylene, linear low density polyethylene, etc. below cm ³ .

The polyamide resin of the present invention is not particularly limited, but usual aliphatic polyamides such as polycaproamide (nylon 6), polyhexamethylene adipamide (nylon 6.6), polyhexamethylene sebacamide ( Nylon 6/10), Polyundecamethylene adipamide (Nylon 6/11), Polyhexamethylene dodecamide (Nylon 6/12), Polyundecanamide (Nylon 11), Polydodecanamide (Nylon 12), Polytetra Methylene adipamide (nylon 4.6), etc., or copolyamides containing these as main constituents, and polyhexamethylene terephthalamide (nylon 6)
T), polyhexamethylene isophthalamide (nylon 6I), aromatic polyamides such as polymethaxylylene adipamide (MXD6), and the like, and mixtures thereof. Particularly preferred polyamide resins are nylon 6, nylon 6.6 and the like. Rigidity of the packaging material of the present invention by using a polyamide resin, puncture resistance,
Properties such as strength and barrier properties can be improved.

The barrier resin other than the polyamide resin of the present invention is a saponified product of ethylene-vinyl acetate copolymer,
Examples thereof include polyester resins, polyvinylidene chloride resins, polyacrylonitrile resins, polypropylene resins and the like.

The linear cuttable packaging material having excellent heat resistance and strength of the present invention means (a) an infrared dichroic method obtained by uniaxially rolling the above-mentioned film containing a high-density polyethylene resin as a main component. A moisture-proof film layer having an orientation ratio of 5 or more in the vertical axis (MD) direction and the horizontal axis (TD) direction, (b) a film layer made of the above polyamide resin, and (c) made of the above barrier resin. It is a linear cut packaging material having excellent heat resistance and strength, which is characterized by comprising a laminate including a barrier resin film layer. The orientation ratio is 5 or more, preferably 5 to 15. If the orientation degree ratio is less than 5, the molecular orientation in the MD direction is insufficient and the linear cut property is deteriorated. On the other hand, when the orientation ratio exceeds 15, the molecular orientation in the MD direction is too high, so that the film tends to tear, the mechanical strength becomes unilateral, and the linear cutting property becomes incompatible. As for the above-mentioned orientation, at least only the film containing the above-mentioned high-density polyethylene resin as a main component is oriented.

The linear cutability (X) of the present invention means a width of 50.
10 mm to the left and right from the center of the tape-shaped strip of mm (total 20
mm width) is expressed as a deviation when linearly stretched, and the value is in the range of 0.8 ≦ X ≦ 1.2. More specifically, as shown in FIG. 1, width A (50 mm) and length E
(400 mm) sample film (thickness 20-25 μm)
Insert notches B (50 mm) in the length direction at positions C (15 mm) from both ends of the sample, and insert the notched center part (width D at the start of the test is 20 mm) in the opposite direction to the sample film. (Indicated by an arrow) was pulled and cut at a pulling speed of 1000 mm / min, and the width of the central portion when the cut length reached H (300 mm) was measured (represented by an average value of 5 points of the sample). It is calculated by the formula, and it can be evaluated that the linear cut property is excellent when the value is in the range of 0.8 or more and 1.2 or less. Straight line cutability = width of central part when reaching 300 mm / width at start of test (20 mm)

The thickness of each film of high-density polyethylene resin, polyamide resin, or barrier resin varies depending on the purpose, application, etc., but is generally 5 to 250 as a general packaging material.
μm, preferably 7 to 200 μm, more preferably 10
A range of up to 150 μm is suitable.

The method for producing the linear cut packaging material having excellent heat resistance and strength of the present invention is to uniaxially roll a high-density polyethylene resin film obtained by an inflation method, a T-die method or the like in advance and apply an adhesive to the oriented film. Although the polyamide resin and the barrier resin may be laminated through the co-extrusion film, the co-extruded film obtained by the inflation method by co-extrusion, the T-die method or the like is preferably 70 ° C. or lower at the melting point of the high density polyethylene resin, preferably 50 ° C. Range, rolling ratio 2.5 times or more, preferably 3 to 10 times, more preferably 3 to 8
It is most preferable that the uniaxial rolling is performed in the double range so that the orientation degree ratio in the vertical axis (MD) direction and the horizontal axis (TD) direction measured by the infrared dichroic method is 5 or more. In order to uniformly roll the film, it is preferable to preheat the film at a temperature not higher than the melting point of the high-density polyethylene resin at 50 ° C., preferably 40 ° C., before uniaxially rolling.

The packaging material of the present invention is uniaxially oriented by a rolling method, but especially by rolling a high density polyethylene resin, the heat resistance is dramatically improved. Examples of the rolling method include a constant speed rolling method, a non-constant speed rolling method, and a multistage rolling method. In addition, the rolling method does not have uneven orientation as compared with the stretching method, and linear cutability can be obtained without reducing mechanical strength.

As described above, in the present invention, the rolling may be performed by rolling a single layer film of high density polyethylene resin (abbreviated as HDPE), and then laminating a polyamide resin (abbreviated as PA) and a barrier resin later. Alternatively, a multilayer film in which PA and barrier resin are laminated on HDPE or a multilayer film in which PA and barrier resin are laminated on HDPE including a sealing material layer may be rolled. For example, HDPE single layer film, HDPE / acid-modified polyethylene (MAnPE
Abbreviated) and the like, HDPE / MAnPE /
Saponified ethylene-vinyl acetate copolymer (abbreviated as EVOH), three-layer coextrusion film such as HDPE / MANnPE / PA or three-layer dry laminate film, HDPE
A 5-layer coextruded film such as / MAnPE / EVOH / MAnPE / PA or a 5-layer dry laminated film may be rolled. The above HDPE, PA and barrier resins may be used alone or in combination of two or more.

For the sealing material layer of the present invention, a resin having a melting point lower than that of the high-density polyethylene resin, an anchor coating agent, an adhesive agent or the like is used. As the resin having a low melting point, a high pressure radical method low density polyethylene (LDPE),
Ethylene- (meth) acrylic acid such as linear low-density polyethylene (LLDPE), ultra-low-density polyethylene (VLDPE), ethylene-vinyl acetate copolymer (EVA), ethylene-ethyl (meth) acrylate (EEA), or Examples thereof include esters, propylene-ethylene random copolymer (RPP), acid-modified polyethylene (MAnPE), acid-modified polypropylene (MAnPP), etc. The sealing material layer is usually provided by a dry laminating method, an extrusion laminating method or the like. The thickness of these layers is 5 to 150 μm.
m, preferably 7-100 μm.

Specific examples of the constitution of the packaging material of the present invention include:
PA / MAnPE / EVOH / MAnPE / HDPE,
EVOH / MAnPE / PA / MAnPE / HDPE,
EVOH / MAnPE / HDPE / MAnPE / PA,
PA / MAnPE / OPP / MAnPE / HDPE, O
PP / MAnPE / PA / MAnPE / HDPE, OP
P / MAnPE / HDPE / MAnPE / PA, PA /
MAnPE / OPET / MAnPE / HDPE, OPE
T / MAnPE / PA / MAnPE / HDPE, OPE
T / MAnPE / HDPE / MAnPE / PA, PA /
MAnPE / EVOH / MAnPE / HDPE / LDP
E, EVOH / MAnPE / PA / MAnPE / HDP
E / LLDPE, EVOH / MAnPE / HDPE / M
AnPE / PA / MAnPE etc. are mentioned. (However, HDPE: high-density polyethylene, LDPE: low-density polyethylene, LLDPE: linear low-density polyethylene, MAnPE: maleic acid-modified polyethylene, EVO
H: Saponified ethylene-vinyl acetate copolymer, PA: Polyamide, OPP: Biaxially oriented PP film, OPET:
Represents a biaxially oriented polyester film. )

The packaging material of the present invention is used for bags, cups, tubes, standing bags, trays and the like.

According to the purpose of use of the present invention, other thermoplastic resins, synthetic rubbers, natural rubbers, inorganic or organic fillers, antioxidants, lubricants, pigments, etc. may be added to the above resin components within the range not departing from the gist of the present invention. UV absorber, cross-linking agent,
You may mix additives, such as a foaming agent and a nucleating agent.

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. (Resin used) High-density polyethylene: [MFR = 1.0 g / 10 min. Density 0.96 g / cm ³ , Nisseki Staflen E710, manufactured by Nippon Petrochemical Co., Ltd.] Low density polyethylene: [MFR = 1.0 g / 10 min. Density 0.92 g / cm ³ , Lexlon F22, manufactured by Nippon Petrochemical Co., Ltd.] Linear low density polyethylene: [MFR = 2.0 g / 10 mi
n. Density 0.92g / cm ³ Linirex AF371
0, manufactured by Nippon Petrochemical Co., Ltd.] Polypropylene: [MFR = 1.0 g / 10 min. Density 0.91 g / cm ³ , Nisseki Polypro, manufactured by Nippon Petrochemical Co., Ltd.] Polyamide resin: nylon copolymer [CM6041XF
-S, manufactured by Toray Industries, Inc.] Barrier resin: EVOH: [MFR = 1.3 g / 10 min. EVAL, manufactured by Kuraray Co., Ltd.] EVAL: [EP-F101, manufactured by Kuraray Co., Ltd.] Biaxially oriented polypropylene (OPP): [Trefan # 2
0, manufactured by Toray Industries, Inc.] Biaxially oriented polyester (OPET): [Emblet #
12, Unitika Ltd.] Biaxially stretched polyamide (ONY): [Emblem # 15,
Unitika Ltd.]

(Test Items and Test Methods) (1) Tensile Test (UTS) and Elongation (%) A 10 mm wide strip was cut from a film sample and a tensile speed of 500 mm / min. Was measured at the speed of. (2) Orientation ratio by infrared dichroism method (3) Straight line cutting property 10 mm from the center of a 50 mm wide strip (20 m in total)
The average value when 5 samples were taken as the deviation when the (m width) was pulled. (4) Haze: According to JIS K7105. (5) Gloss: According to JIS Z8741. (6) Water vapor transmission rate: 10 cm × 10 c for a film sample
Make a bag of m (100 cm ² ), enclose approximately 5 g of calcium chloride, seal in four directions, and measure the exact weight (4 digits after the decimal point). Next, a test is conducted for 1 week (168 hours) in an oven of constant temperature and humidity of 40 ° C. and 90% RH. When the test is completed, the weight is accurately measured again, and the water vapor transmission rate is calculated by the following formula. Water vapor transmission rate = [weight after test (g) -weight before test (g)] x K (g / m ² · 24hrs) K: unit conversion coefficient (7) oxygen permeability (cc / m ² · 24hrs · atm) ): JIS K71
According to 26.

(Examples 1 to 4) High density polyethylene (HDP) was prepared by a multi-layer T-die method using a 50 mmφ extruder.
E) and a polyamide resin (PA) were used, and an ethylene-vinyl acetate copolymer saponification product (EVOH) was passed through an acid-modified polyethylene (abbreviated as NP) by a multi-layer T-die method using a 50 mmφ extruder. The raw material films having various thicknesses shown below were prepared and rolled at various rolling ratios shown in Table 1 by a rolling method to obtain the packaging material (abbreviated as RNH) of the present invention (total thickness 25 μm. PA / NP / EVOH / The thickness configuration of NP / HDPE made 5.5 / 5/4/5 / 5.5 μm). The results of evaluating the packaging material are shown in Table 1. The straight line cutability was good.

(Embodiment 5) In addition to the RNH used in Embodiment 1,
Polypropylene film (C
PP (abbreviated as PP) (thickness 40 μm) was laminated to make the packaging material of the present invention. The results evaluated in the same manner as in Example 1 are shown in Table 1.
It was shown to. The straight line cutting property was good.

(Example 6) In the RNH used in Example 1,
A linear low-density polyethylene film (abbreviated as LLDPE) (thickness 40 μm) was laminated by a dry lamination method to prepare a packaging material of the present invention. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1. The straight line cutting property was good.

(Example 7) In the RNH used in Example 1,
A biaxially stretched polyester film (OPET, thickness 12 μm) and a polypropylene film (CPP) (thickness 40 μm) were laminated by the dry lamination method in the constitution shown in Table 1 to prepare a packaging material of the present invention. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1. The straight line cutting property was good.

(Comparative Example 1) In the same manner as in Example 1, the multilayer T
A raw film having the thickness shown in Table 1 is prepared by the die method,
A packaging material was made by rolling with a rolling ratio of 3.0 times by the rolling method (total thickness 25 μm, PA / NP / EVOH / NP / H
DPE thickness composition is 5.5 / 5/4/5 / 5.5μ
m). The results of evaluation performed in the same manner as in Example 1 are shown in Table 1. The linear cut property was 0.5, which was poor.

(Comparative Example 2) OPP film (thickness: 20 μm)
m), a commercial Eval film (thickness 12 μm) and a polypropylene film (CPP, thickness 40 μm) were laminated by the dry lamination method with the constitution shown in Table 1. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1. When a straight line cutability test was performed, the tape was cut in the middle before reaching 300 mm. There is no straight line cutting property.

(Comparative Example 3) OPET film (thickness: 12)
μm), a commercial Eval film (thickness 12 μm) and a linear low-density polyethylene film (LLDPE, thickness 40 μm) were laminated by the dry lamination method in the constitution shown in Table 1. The results of evaluation performed in the same manner as in Example 1 are shown in Table 1. When tested for linear cutability, it was 30
Before reaching 0 mm, it was cut by tapering on the way. There is no straight line cutting property.

(Comparative Example 4) ONY film (thickness: 15 μm)
m), a commercial Eval film (thickness 12 μm) and a linear low-density polyethylene film (LLDPE, thickness 40 μm) were laminated by the dry lamination method with the constitution shown in Table 1. The results evaluated in the same manner as in Example 1 are shown in Table 1.
It was shown to. When tested for linear cutability, it was 300
The taper was cut on the way before reaching mm. There is no straight line cutting property.

[0029]

[Table 1]

[0030]

The packaging material having excellent heat resistance and strength of the present invention has a vertical axis (a) obtained by an infrared dichroic method obtained by uniaxially rolling a film containing a high-density polyethylene resin as a main component. A moisture-proof film layer having an orientation degree ratio of 5 or more in the (MD) direction and the horizontal axis (TD) direction, a (b) polyamide resin film layer, and (c) a barrier resin film layer made of a barrier resin other than the polyamide resin. It is characterized in that it is made of a laminated body containing, has a high puncture resistance and strength, has moisture resistance and aroma retention, and can be a packaging material that can be easily cut linearly by hand, rice cake packaging, confectionery packaging, shaving bags, It is preferably used for packaging mayonnaise, ketchup, soup, mustard, miso, pickles and the like. Also, in the manufacturing process, it can be continuously manufactured at low cost.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a test method of linear cuttability (X).

[Explanation of symbols] A width of test film B length of notch 50 mm C length from end of test film D width of central portion E length of test film H cut length 300 mm

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B65D 65/40 A 9028-3E

Claims (2)

[Claims] 1. A vertical axis (MD) direction and a horizontal axis (T) measured by an infrared dichroic method (a) obtained by uniaxially rolling a film containing a high-density polyethylene resin as a main component.
A moisture-proof film layer having an orientation ratio in the D) direction of 5 or more,
A linear cut packaging material having excellent heat resistance and strength, which is characterized by comprising a laminate comprising a (b) polyamide resin film layer and (c) a barrier resin film layer made of a barrier resin other than the polyamide resin. 2. The linear cut property (X) is 0.8 ≦ X ≦.
The linear cut packaging material having excellent heat resistance and strength according to claim 1, wherein the packaging material is in the range of 1.2.