JPH08276545A - Composite film for packing rice cake - Google Patents

Abstract

PURPOSE: To prevent breakage or the like from being generated by bearing outer force of rubbing action or the like by a method wherein a non-oriented polyethylene layer or polypropylene layer is laminated on an opposite side to a vinylidene chloride coat layer of a base material layer. CONSTITUTION: For this composite film for packing a rice cake, a non-oriented polyethylene layer or a non-oriented polypropylene layer is laminated on an opposite side to a vinylidene chloride coat layer of a base material layer having the vinylidene chloride coat layer. For an oriented polypropylene film or an oriented nylon film of the base material layer having the vinylidene chloride coat layer, that of 5-50μm thickness is generally used. Further, as resin forming the non-oriented polyethylene layer or the non-oriented polypropylene layer, low density polyethylene, medium density polyethylene, and linear low density polyethylene are preferable, three kinds of polyethylene of 0.910-0.940g/cm density are especially preferable, and those of 0.915-0.935g/cm are further preferable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite film for packing rice cakes, and more specifically, to improve the preservability of aseptic or sterilized packaging rice cakes by preventing breakage due to rubbing or the like and generation of pinholes. It was done.

[0002]

2. Description of the Related Art As a composite film used as a packing material for hermetically packing rice cake, a vinylidene chloride-coated stretched polypropylene or vinylidene chloride whose outer layer, which is a base material layer, has low air permeability (or oxygen hardly permeates). Those formed from a film of coated stretched nylon are well known. In this known composite film, a printing layer, an adhesive layer or an anchor coating layer, and a polyolefin layer are sequentially laminated on the vinylidene chloride coat layer side, and the polyolefin layer is used as an inner layer.

[0003]

In the packaging material formed of the above-mentioned known composite film, especially when the rice cake to be packaged is a plate-like rice cake, the rice cake is rubbed by the corrugated cardboard or the rice cake corner during transportation of the product. Torn and pinholes occurred,
Due to this, there is a problem that the original storability of the composite film package is remarkably lowered, and the commercial value is impaired due to generation of mold and the like.

The inventors of the present invention have found that the breakage and the occurrence of pinholes are mainly caused by the stretched film which is the material of the base material layer of the composite film. Therefore, the object of the present invention is to improve the above-mentioned conventionally known composite film by laminating a non-stretched film of a further specified material on the base material layer side so as to withstand external force such as rubbing and not to break. It is to provide a composite film for packing rice cakes.

[0005]

In order to achieve the above object, a composite film for mochi packaging, which is a feature of the present invention, has a vinylidene chloride coat layer on the side opposite to the vinylidene chloride coat layer. It is formed by laminating a stretched polyethylene layer or a non-stretched polypropylene layer.

The composite film for packing rice cake is preferably used by laminating a polyolefin layer on the vinylidene chloride coat layer side, and the polyolefin resin usually used for the polyolefin layer is the unstretched polyethylene layer or unstretched layer. It is preferable to use a resin having a lower melting point than that of the polyethylene resin or polypropylene resin used for the polypropylene layer and / or the resin for the base material layer, more preferably a resin having a low melting point of 10 ° C or higher, particularly preferably 15 ° C or higher. A resin having a low melting point is used.

The base material layer is a propylene homopolymer,
Propylene / ethylene random copolymer and the like, preferably polypropylene homopolymer oriented polypropylene film or 6-nylon, 6,6-nylon, 12-nylon and the like, preferably 6-nylon, 6,6-nylon It is preferably formed of a stretched nylon film.

The composite film for mochi packaging of the present invention is constructed as described above, and the constituent materials used for carrying out the present invention will be described below. As the stretched polypropylene film or stretched nylon film of the base material layer having a vinylidene chloride coat layer, those having a thickness of generally 5 to 50 μ can be used, but preferably, the stretched polypropylene film has a thickness of 15 to 40 μm, and the stretched nylon film. Is 10 to 30 μ.

As the resin for forming the unstretched polyethylene layer or the unstretched polypropylene layer, low density, medium density, high density polyethylene, linear low density polyethylene, ethylene / vinyl acetate copolymer are used. , Ethylene / acrylic acid copolymer (EAA), ethylene / methacrylic acid copolymer (EMAA), ionomer (EAA, EMAA metal salt cross-linked product, trade name-Surrin etc.), propylene homopolymer, propylene / ethylene random A copolymer, a random copolymer of propylene and another α-olefin, a propylene / ethylene block copolymer, or the like can be used.

Of these, low density polyethylene, medium density polyethylene and linear low density polyethylene are preferable, and in particular, the density is 0.910 to 0.940 g / cm ³ , and more preferably 0.
915 to 0.935 g / cm ³ of the above three polyethylenes are preferred. The unstretched polyethylene layer or unstretched polypropylene layer is usually used in a thickness range of 10 to 50 µ, preferably 15 to 40 µ.

Furthermore, the resin used for the polyolefin layer is low density, medium density or high density polyethylene,
Linear low-density polyethylene (copolymer of ethylene and α-olefin having 4 to 12 carbon atoms, density 0.88 to 0.93 g /
cm ³ , preferably 0.900 to 0.925 g / cm ³ ), ethylene / vinyl acetate copolymer, ethylene / acrylic acid copolymer, ethylene / methacrylic acid copolymer, ionomer and the like. Among these, preferred are low density polyethylene, linear low density polyethylene, ethylene
It is a vinyl acetate copolymer. The polyolefin layer is usually used in a thickness range of 10 to 100 µ, preferably 15 to 80 µ.

Since the polyolefin layer can be preferably used as a heat-sealing layer when a bag is made of the present composite film, the polyolefin layer for forming the non-stretched polyethylene layer or the non-stretched polypropylene layer as the outermost layer is used. A resin having a higher melting point than that of the resin forming the polyrefin layer, which is a heat seal layer, is usually used.
High melting point of 10 ℃ or more, 60 ℃, preferably 15-40
Those that are higher by ℃ are used.

The base layer and the unstretched polyethylene layer or the unstretched polypropylene layer can be laminated with an adhesive or an anchor coating agent. On the other hand, the lamination of the vinylidene chloride coat layer and the polyolefin layer can be carried out, for example, after printing the vinylidene chloride coat layer, or the vinylidene chloride coat layer or the printing layer is provided with an adhesive layer or an anchor coat. It can also be performed by providing layers.

Known adhesives and anchor coating agents can be used here. For example, as the adhesive, isocyanate type, polyester / isocyanate type, polyether / isocyanate type, etc. are used. The amount is 0.5g / cm ² or more, preferably 0.5 to 7g / cm ²
As the anchor coating agent, isocyanate-based, polyester-isocyanate-based, polyether-based
Isocyanate-based, polyethyleneamine-based, organic titanate-based, polybutadiene-based are used, and the coating amount is
For example, 0.01 to 1.0 g / cm ² (dry), preferably 0.05 to 0.
It is 58 g / cm ² (dry).

The composite film of the present invention can be manufactured by a known method. For example, an extruding laminating method in which an anchor coating agent is applied to the surface of the substrate film opposite to the vinylidene chloride coating layer, dried, and then unstretched polyethylene or unstretched polypropylene is laminated, or a pre-formed A stretched polyethylene film or a non-stretched polypropylene film is attached by optionally using an anchor coating agent and / or an adhesive, and is manufactured by a dry lamination method or the like. The obtained composite film of the present invention has a thickness of 40 to 150 μ, preferably 50 to 130 μ, and particularly in the thickness range of 60 to 90 μ, the invention effect is remarkable.

[0016]

EXAMPLES In each of the following Examples of the present invention and Comparative Examples thereof, the rate of pinholes was determined by the Gelbo flex test (3000 times at 23 ° C.) conducted according to ASTM F392, and the obstruction was observed from one corner to the center. 180 pieces of bag-shaped rice cakes (40g / piece) each packed in a hexagonal drum with a side of 30cm
A drop test in which 5 bags were packed in a 250 mm bag and rotated for 3 hours at a rotation speed of 7 times / min. A bag filled with water was folded to form a corner, and that part was made into cardboard (carton). Paper) and load 50 g, amplitude 120 mm, temperature at speed 30 times / min
It was evaluated by a rubbing resistance test in which it was rubbed 500 times in a room at 20 ° C and a humidity of 65% RH.

Example 1: Vinylidene chloride coated stretched nylon film manufactured by Unitika Ltd. (trade name: DC)
R, thickness 15μ and abbreviated as KNy), Mitsubishi Chemical Corporation low density polyethylene LC500 (MI = 4g / 10 min, density = 0.918g / cm ³ abbreviated as LDPE), Toyobo ( Unstretched homopolypropylene film P-1111
(Thickness 25μ and abbreviated as CPP), Toyobo Co., Ltd.
Polyethylene terephthalate film E5102 (thickness 12
μ, abbreviated as PET), linear low density polyethylene 10240 manufactured by Idemitsu Petrochemical Co., Ltd. (MI = 10 g / 10 min, density =
0.914 g / cm ³ and abbreviated as L-LDPE).

Then, a CPP having a thickness of 25 μ is added to KNy having a thickness of 15 μ.
Of the vinylidene chloride layer on the opposite side of the vinylidene chloride layer by the dry lamination method, and then on the vinylidene chloride coated surface.
L-LDPE was laminated by an extrusion laminating method so that the thickness was 35 μm. A polyurethane adhesive (A-968 manufactured by Takeda Pharmaceutical Co., Ltd.) was used as the adhesive during the dry laminate molding described above, and a one-pack type isocyanate AC agent (Japan Soda Co., Ltd. T-120) was used. The composite film produced in this way has a thickness of 75μ
2 is a composite film of Example 1 according to the present invention.

COMPARATIVE EXAMPLE 1 AND COMPARATIVE EXAMPLE 2 In the same manner as in Example 1, KNy having a thickness of 15 μm and LDPE having a thickness of 60 μm were extruded and laminated on the vinylidene chloride coat layer side by a laminating method.
A 75 μ composite film was obtained, and this composite film was used as Comparative Example 1. In addition, in the same manner as in Example 1, KN with a thickness of 15 μm
On the opposite side of the vinylidene chloride coating layer of y,
T was laminated by a dry laminating method, and then LDPE having a thickness of 60 μ was extruded on the vinylidene chloride coat layer side surface and laminated by a laminating method to produce a 87 μ-thick composite film. This composite film was used as Comparative Example 2. .

Then, the above-mentioned Example 1 and Comparative Examples 1 and 2 are used.
Table 1 below shows the results of evaluating the pinhole generation rate by wrapping the plate-shaped rice cake with each of the composite films of No. 1 above.

[0021]

[Table 1]

Example 2: As a material, a linear low-density polyethylene TUX • FC (a copolymer of ethylene and 4-methylpentene-1 and abbreviated as L-LDPE-60μ) manufactured by Tohcello Co., Ltd., Idemitsu Petrochemical Co., Ltd. ) Linear low density polyethylene 10
18D (copolymer of ethylene and octene-1 with L-LDPE-
30 μ), EVA LV260 (ethylene / vinyl acetate copolymer, abbreviated as EVA) manufactured by Mitsubishi Chemical Corporation, and KNy and LDPE having a thickness of 15 μ used in Example 1 were used.

Then, L-LDPE-30μ was extruded on the opposite side of the vinylidene chloride coat layer of KNy having a thickness of 15 μm to form an unstretched polyethylene layer having a thickness of 30 μm by a laminating method, and then laminated on the vinylidene chloride coat layer side. EVA was laminated by extrusion lamination so as to have a thickness of 45 μm to obtain a composite film of Example 2 according to the present invention having a thickness of 90 μm.

Comparative Example 3: LDPE was extruded on the surface of the vinylidene chloride coating layer side of KNy having a thickness of 15 μm so as to have a thickness of 15 μm by laminating, and L-LD was further laminated on the LDPE surface.
PE-60μ was laminated by extrusion lamination so as to have a thickness of 60μ to obtain a 90μ-thick composite film. This composite film was used as Comparative Example 3.

Then, using the composite films of Example 2 and Comparative Example 3 described above, respectively, Example 1 and Comparative Examples 1 and 2 were used.
Table 2 below shows the results of evaluation of the occurrence rate of pinholes in the same manner as in.

[0026]

[Table 2]

The present invention is as described above, and since a non-stretched polyethylene layer or polypropylene layer is laminated as the outermost layer on the base material layer having a vinylidene chloride coat layer of the composite film, the present composite film. The package of rice cakes hermetically sealed by means of excellent abrasion resistance, the problem of being broken even when rubbed during transportation etc. is resolved, and it is effective in improving the preservability of sterile or sterilized packaged rice cakes. When it is formed into a bag and used, there is also an advantage that curling that tends to occur at the filling port can be prevented.

Continuation of front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area C08J 7/04 CES C08J 7/04 CESP

Claims (3)

[Claims] 1. A composite film for rice cake packaging, characterized in that a non-stretched polyethylene layer or a non-stretched polypropylene layer is laminated on the side of the substrate layer having a vinylidene chloride coat layer opposite to the vinylidene chloride coat layer. . 2. The composite film for packing rice cake according to claim 1, wherein a polyolefin layer is further laminated on the vinylidene chloride coat layer side. 3. The composite film for packing rice cake according to claim 1, wherein the base material layer is a stretched polypropylene film or a stretched nylon film.