JPH01281935A - Packaging material - Google Patents

Abstract

PURPOSE:To enable gas barrier properties to be easily changed at low cost with its excellent transparency by specifying the adhesion strength of the resin layer having the specified value or more of the oxygen gas-permeating amount from the side of a packed object to the layer having the other specified value or less of oxygen gas-permeating amount. CONSTITUTION:A constructed layer is composed of the resin layer 3 with low gas barrier properties wherein the oxygen gas-permeating amount from the side of a packed object is 100cc/m<2>.24Hr.100mum or more and the resin layer with high gas barrier properties wherein oxygen gas-permeating amount is 10cc/m<2>.24Hr.100mum or less with the adhesion layer 2 of the adhesion strength of 20-200/25mm width intervening therebetween. To suppress said adhesion strength, coextrusion process is used, and the strength may be suppressed in high accuracy by selecting the resin composition of the adhesion layer. Consequently, the packaging material whose transparency may be regulated and which may be removed, is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a packaging device A for paddy rice with excellent transparency, which allows gas barrier properties to be removed if necessary.

[Conventional technology]

In the toiletry field, such as air fresheners and pesticides, packaging materials with low gas barrier properties are used, resulting in shortened product lifespans, and the use of packaging materials with high gas barrier properties causes troublesome handling and problems with gas barrier properties. High packaging materials and low packaging 4
Methods such as combining two types of silk as shown in 4o'4, and methods such as combining with Japanese paper as in Japanese Utility Model Publication No. 62-162024 have been considered, but both methods have the problem of high cost. There were also issues with transparency. Furthermore, in the food industry, high gas barrier packaging is used for beef, and storage
1), there was a problem that although it did not spoil, the red meat would wither due to lack of oxygen and the product value would decrease.Therefore, when gas barrier properties are required, gas easily leaks after 1υI. Packaging materials that can reduce barrier properties have been desired.

[Problems to be Solved by the Invention] The present invention was researched to obtain a packaging material r1 that has excellent transparency, which was impossible with conventional packaging materials, and which is inexpensive and whose gas barrier properties can be easily changed. As a result, we obtained knowledge about the composition of the adhesive layer and the region of adhesive strength where the resin layer with high gas barrier properties and the resin layer with low gas barrier properties can be easily peeled off, but can withstand molding processing before peeling. The present invention was completed as a result of consideration of the lamination method.

In the present invention, the layer structure has an oxygen gas permeation rate of 10% from the packaged object side.
0cc/rrr ・2・24Hr・100 μm or more resin layer (1), adhesive layer (2) with adhesive strength of 20 to 200 g / 25 mm width with resin layer (1) or resin (3)
), oxygen gas permeation rate is 10cc/rK -2・24Hr
- A packaging material characterized by a resin layer (3) of 1001 tm or less, and a method for producing the same.

The low gas barrier resin used in the present invention is
Oxygen gas permeation rate is 100 cc/+f at a thickness of 100 μm
- 2.24 hours or more. 100cc/ni
- If the resin has an oxygen gas permeation rate of 2.24 hours or less, the gas permeation rate after removing the gas barrier resin layer will be insufficient. Specifically, in the case of air fresheners, the fragrance will permeate through the packaging material and evaporate. Not done. On the other hand, in raw meat packaging, oxygen gas cannot penetrate sufficiently and the recovery of lean meat is delayed.

Oxygen gas permeation amount is 100cc/+d・2・24Hr・
Examples of resins with a diameter of 100 μm or more include polyolefin resins and copolymers thereof, polystyrene, polycarbonate, and soft hinyl chloride. Further, in order to increase the amount of oxygen gas permeation, a filler or the like may be added to the above-mentioned resin to an extent that does not impair transparency.

In addition, as a resin with high gas barrier properties, the oxygen gas permeation rate is 10 cc/rrf ・2.24 Hr or less at a thickness of 100 μm, and it is suitable for saponified ethylene/vinyl acetate copolymer, polyvinylidene chloride, polyamide, and polyacrylonitrile. can be used. .

[For production]

An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of one embodiment of the packaging material of the present invention, in which 1 is a resin layer with high gas barrier properties, and 3 is a resin layer with low gas barrier properties. 2 is an adhesive layer, but in this example, for layer 1,
The adhesive strength is kept low, and when layer I is peeled off, a cross-sectional view as shown in FIG. 2 is obtained.

The adhesive layer must have an adhesive strength of 20-200 g/25 mm width for either layer 1 or layer 3. If the width is 200 g/2 S mm or more, peeling is not easy, and the peeled surface of 4 becomes rough, causing deterioration in appearance.

On the other hand, if the adhesive strength is less than 20 g/25111111 width, peeling phenomenon will easily occur during film processing and the product will not be produced.

In the present invention, the adhesive strength of the adhesive layer is important, and the resin composition of the adhesive layer is determined by the types of resins in layers 1 and 3 to be adhered.

Furthermore, in order to sufficiently suppress the adhesive strength, it is necessary to consider the lamination method. In the dry lamination method that uses adhesives, not only is it extremely difficult to prepare the adhesive to adjust the adhesive strength, but even if such adhesives are used, the thickness of the applied adhesive is uneven, making it completely difficult to prepare the adhesive. , the adhesive strength cannot be suppressed.

In addition, in the hot press method, heat conduction to the bonding surfaces between each resin layer is insufficient, so only low bonding strength can be obtained and variations are large. Moreover, the processing cost becomes very high.

In the present invention, as a method for suppressing the adhesive strength, the test δ=t
Using a co-extrusion method, it was discovered that the adhesive layer could be suppressed with higher accuracy by selecting the resin composition of the adhesive layer. In the coextrusion method, completely melted resins are laminated under constant pressure inside a sheeting die and extruded, so stable adhesive strength can be easily obtained as long as the extrusion conditions are kept constant.

〔Example〕

Resin with high quality gas barrier properties (Kuraray, Epal E105) and wood BF with low gas barrier properties; (Sumitomo Chemical Everty)
H2021F) was coextruded using a three-layer multi-manifold die with an adhesive layer (Ehafrex P 2505 C, manufactured by Mitsui Petrochemical Industries, Ltd.) in the middle.

The thicker one is EI05”301!m /P2505C・301
The total length was 120 μm (1 m/H2O21F/60 μm). When the oxygen gas permeation of the EVAL E105 layer before and after peeling and removal and the peel strength of the EVAL 2101 layer were measured, the following results were obtained.

(1) Oxygen gas permeation rate f Before peeling 1・5°c/rK -2・24Hr ■After peeling 2200 cc/n I・2・24Hr (
2) Peel strength 1.05 g/25 mm
Width [Effect of the Invention] By following the packaging material and manufacturing method of the present invention, a packaging material with excellent transparency and gas barrier properties that can be adjusted and removed, which could not be obtained conventionally, can be obtained, and it is widely used in the toilet cleaner 1 food field. Available.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of one embodiment of the packaging material of the present invention, and FIG. 2 is a sectional view after the resin layer with high gas barrier properties has been peeled off and removed. Patent applicant Sumitomo Bakelite Co., Ltd. Figure 1

Claims (2)

[Claims] (1) The layer structure has an oxygen gas permeation rate of 100 from the packaged object side.
cc/m^2・24Hr・100μm or more resin layer (1
), adhesive strength with resin layer (1) or resin layer (3) is 20
~200g/25mm width adhesive layer (2), oxygen gas permeation amount of 10cc/24Hr・100μm or less resin layer (3)
) A packaging material characterized by: (2) The packaging material according to item (1), further comprising a protective layer (4) on the outer surface of the resin layer (3).