JP2732656B2 - Laminated film or sheet and carton made therefrom - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a laminated film or sheet obtained by laminating a layer made of a specific resin and a layer of paper, and a carton made therefrom. Comprises two layers of poly-4-methyl-1-pentene and paper,
The present invention relates to a film-like sheet excellent in oil-impermeable and a carton made therefrom.

(Conventional technology and its problems) In recent years, cooking methods using a microwave oven have rapidly advanced and spread, and cooking of various types of foods such as dishes and confections has become extremely easy.

When cooking food in a microwave oven, for example, the food for cooking is stored in a tray-like container formed from a laminated sheet of an inner layer made of a 4-methyl-1-pentene polymer and an outer layer made of paper, and is subjected to high frequency. Heating is performed.

Some of the foods include, for example, ingredients containing fats and oils components such as butter and margarine, such as pound cakes, and hamburgers, etc., heated by a microwave oven, and then cooked with a sauce containing fats and oils components. May be completed, but may be stored in a box-shaped container after heating with a microwave oven or after applying a sauce containing an oil or fat component after the heating.

In such a case, with the passage of time, the fat and oil component permeates into the paper layer constituting the container, and the entire paper layer becomes oil-paper-like and impairs the appearance of the container. May be contaminated with oils and fats.

(Object of the Invention) Therefore, an object of the present invention is to provide a laminated sheet that can be used as a container material that can completely prevent penetration of fats and oils from stored cooked food.

(Means for Solving the Problems) According to the present invention, a layer (A) composed of poly-4-methyl-1-pentene having a melting point of 220 to 245 ° C. and poly 4-methyl having a melting point of 190 to 230 ° C. -1- An intermediate layer (B) composed of pentene and a layer (C) composed of paper;
A laminated film or sheet is provided, wherein the poly-4-methyl-1-pentene of the layer (B) has a lower melting point than the poly-4-methyl-1-pentene used for the layer (A).

In the following description, the poly-4-methyl-1-pentene used for the (A) layer is referred to as “high melting point poly-4-methyl-1-pentene” and the poly-4-methyl-1-pentene used for the (B) layer.
Methyl-1-pentene is referred to as "low melting point poly-4-methyl-1".
-Pentene ".

(Description of Preferred Embodiment) In the present invention, the high melting point poly-4-methyl-1-pentene is a homopolymer of 4-methyl-1-pentene or 4-methyl-1-pentene and usually 20 mol%. Or less, preferably 12 mol% or less of other α-olefins such as ethylene, propylene, 1-butene, 1-hexene, 1-octene, 1-decene, 1-tetradecene, 1
A copolymer with an α-olefin having 2 to 20 carbon atoms, such as octadecene, having a melting point of 220 to 245 ° C., preferably
Crystalline poly-4-methyl-1-pentene at 225 to 240 ° C. is preferably used, and this polymer can be produced by a method known per se, for example, a method described in JP-A-59-206418. it can. The high melting point poly-4-methyl-1-pentene preferably has an MFR of 5 to 1000 g / 10 minutes, and among them, 70 to 300 g / 10 minutes is particularly preferred because of good moldability and heat resistance. can do.

Further, the low melting point poly-4-methyl-1- according to the present invention.
The MFR of pentene is the high melting point poly 4-methyl-1-
It is the same as pentene, but has a melting point of 190 to 230 ° C, preferably 200 to 230 ° C. This polymer can also be polymerized by the method described in JP-A-59-206418. In this case, a polymer having the above-mentioned melting point range can be obtained by making the copolymerization amount of the α-olefin larger than that of the high-melting point poly-4-methyl-1-pentene.

Generally, the melting point decreases with an increase in the amount of α-olefin to be copolymerized, but it is also affected by factors such as the type of α-olefin, the catalyst used, and other polymerization conditions. However, since the relationship between these factors and the melting point can be determined experimentally in advance, it is easy for those skilled in the art to obtain poly-4-methyl-1-pentene having the intended melting point.

As described above, the high melting point poly-4-methyl-1-pentene and the low melting point poly-4-methyl-1-pentene in the present invention have different melting points, and the melting point ranges of the two partially overlap. However, high melting point poly-4-methyl-
It is necessary to use 1-pentene having a melting point higher than that of poly-4-methyl-1-pentene having a low melting point which forms the intermediate layer.

Thus, a high-rigidity poly 4-methyl-1- with a high melting point
A paper layer in which both layers are provided as another layer by heating in a microwave oven, with a single layer of pentene and a low-rigid poly-4-methyl-1-pentene layer having a lower melting point as an intermediate layer. Thus, a laminated sheet suitable as a container material can be provided without the permeation of the oil component.

As the paper constituting the other layer, clay coated paper, milk carton paper or the like which is usually used as a box-making material is used.
In the case where pinholes or very small cracks enter the two layers made of 1-pentene due to external impact or rubbing, or where the case where the oil component penetrates from the end face of the laminated sheet occurs. However, it is recommended to use clay-coated paper in that the penetration of oils and fats is extremely slow, and since this clay-coated paper has excellent printability, a printing layer may be formed on the outer surface of the container as necessary. Also when forming, it becomes a suitable printing base material.

The laminated sheet of the present invention can be obtained by directly extrusion-coating two kinds of poly-4-methyl-1-pentene constituting an intermediate layer and another layer on paper by coextrusion, or by combining paper with the intermediate layer. In order to further enhance the adhesive strength of the paper, a method known per se in advance, such as an organic titanium-based, polyethyleneimine-based, or isocyanate-based anchor coating agent, or an adhesive polyolefin, high-pressure polyethylene, or the like, is applied to the surface of the paper in advance. Extrusion coating may be performed after the base is applied.

In the present invention, the poly 4-
Methyl-1-pentene is excellent in extrusion coating properties under high speed, so that it can be formed using a common co-extrusion coating apparatus.
Extrusion coating at a high speed is possible, which results in a laminated sheet with excellent mechanical properties and interlayer adhesion.However, during extrusion coating, air or nitrogen gas is applied to both ends of the film. By blowing a gas such as this, it is possible to improve the neck-in and the ear fluctuating at both ends of the film-like material, at this time, preferably in the vicinity of the film-like material is in contact with the substrate, the film-like material By blowing the gas from the side not in contact with the surface, extrusion coating at a high speed can be achieved more stably.

As a method of blowing gas onto the film-like material, specifically, for example, a metal pipe such as an aluminum pipe or a copper pipe, or a conduit such as a thermoplastic resin pipe is arranged downstream of the die, and the gas is supplied from the pipe to the poly 4- tube. A method in which a film-like material of methyl-1-pentene is sprayed at an arbitrary position while being extruded from a die and in contact with a substrate, preferably in the vicinity of a contact point where the film-like material is coated on the substrate, may be used. The pressure of the gas at the time of spraying is appropriately determined in consideration of the thickness of the film material to be coated, and is usually in the range of 0.5 to ⁵ kg / cm ² G. The diameter of the tip of the nozzle to be sprayed is usually in the range of 1 mm ² to 50 mm ² , preferably 5 mm ² to 10 mm ² . The distance from the tip of the nozzle to the film-shaped material is usually in the range of 2 mm to 100 mm, preferably 5 mm to 20 mm. Still further, it is preferable that the tip of the nozzle to be sprayed be directed from the inside to the outside of the film-like material, since the film-like material is expanded by the blown gas and the effect of narrowing the neck-in is further increased.

In the present invention, the extrusion temperature at the time of extruding and coating the two kinds of poly-4-methyl-1-pentene constituting the inner layer and the intermediate layer on the substrate can be usually from 250 to 370 ° C, preferably from 290 to 340 ° C. . Extrusion coating speed (coating material take-off speed) is 100m / min or more, preferably 150 to 500m / min.
Can be performed in the range of High melting point poly 4 in laminated sheet
-Methyl-1-pentene layer / Poly-4-methyl of low melting point-
The thickness of the 1-pentene layer / paper can be arbitrarily selected, but is usually 1 to 2000 μm / 1 to 2000 μm / 5 to 5000 μm.
m, preferably 5 to 50 μm / 5 to 50 μm / 1.
A range from 00 to 600 μm is used.

The poly-4-methyl-1-pentene used in the present invention has a weather-resistant stabilizer, a heat-resistant stabilizer, an antistatic agent, an anti-fogging agent, an anti-blocking agent known per se, as long as the object of the present invention is not impaired. Compounding agents such as slip agents and coloring agents can be added.

(Effects of the Invention) According to the present invention, a laminated sheet composed of a high melting point poly-4-methyl-1-pentene layer / a low melting point poly-4-methyl-1-pentene layer / paper layer has a high melting point. The penetration of oil and fat components from the side of the poly-4-methyl-1-pentene layer is completely prevented, and the carton made from this laminated sheet has excellent oil resistance, so that it can be used for cooking with an electronic lens. It can be suitably used as a tray or as a packaging container for foods containing fats and oils components such as cakes and sweet buns.

(Example) Hereinafter, the present invention will be described in detail based on examples.

The melting point, MFR and initial flexural modulus in Examples were measured by the following methods.

The melting point in the present invention is determined by a differential scanning calorimeter (ModelDSC).
-II: manufactured by PerkinElmer Co., Ltd.)
This is the peak temperature when an endothermic curve is measured at a heating rate of 10 ° C./min after cooling to 20 ° C./min, cooling to room temperature at a rate of 20 ° C./min, crystallization and keeping at room temperature for 1 minute. In the poly-4-methyl-1-pentene used in the present invention, one or more endothermic peaks may be detected. In such a case, the highest peak temperature is determined as the melting point.

MFR: Measured at 260 ° C. under a load of 5 kg according to ASTM D 1238.

Initial flexural modulus: measured according to ASTM D790. (However, the test speed was 5 mm / min.) Example 1. Melting point: 237 ° C., MFR: 180 g / 10 min, initial flexural modulus: 13,000 kg
/ cm ² crystalline copolymer of 4-methyl-1-pentene and 1-decene (1-decene content 2.5 wt%) (hereinafter PMP (I)
And a crystalline copolymer of 4-methyl-1-pentene and 1-octadecene having a melting point of 226 ° C., an MFR of 26 g / 10 min and an initial flexural modulus of 5,000 kg / cm ² (1-octadecene content of 6 w
t%) (hereinafter referred to as PMP (II)) was melted by an extruder having a diameter of 65 mm, and laminated onto a milk carton paper having a basis weight of 290 g / 10 min using a co-extruded two-layer die. The total coat thickness was 30μ and each layer was 15μ. 10 cm × 10 cm × 5 c so that the inner surface becomes a coat layer from the obtained laminated paper
I made a box of m (depth).

Weigh 40 g of commercially available margarine (made by Snow Brand Milk Products) into a box, and place it in a microwave (Matsushita Electric Industrial; type NE-A740)
For 30 seconds. After heating, it was allowed to stand at room temperature, and the number of days until margarine exuded to the outer surface on the paper side was visually determined.

Using the same box as above, raw powder of chocolate cake (house gourmet gourmet, house food) and water were added, and the mixture was cooked in the same microwave oven for 3 minutes and 30 seconds. After cooking, it was observed whether the contents permeated out without removing the contents.

Put the butter cake (house gourmet gourmet, house food) and the water in the same box
Cooked for 20 minutes at a set temperature of 0 ° C. After cooking, it was observed whether the contents permeated out without removing the contents.

 Table 1 shows the results.

Example 2. Instead of PMP (II) used in Example 1, melting point 229 ° C,
Crystalline copolymer of 4-methyl-1-pentene and octadecene having an MFR of 26 g / 10 min and an initial flexural modulus of 8,000 kg / cm ² (octadecene content of 4 wt%) (hereinafter referred to as PMP (III))
Was performed in the same manner as in Example 1 except that Table 1 shows the results.

Comparative Example 1. The same operation as in Example 1 was performed except that PMP (I) used in Example 1 was used for both of the two layers of the co-extruded layer.

 Table 1 shows the results.

Comparative Example 2 PMP (I) was laminated with a coat thickness of 15 μ using a single-layer die instead of the co-extrusion two-layer die used in Example 1. Open the semi-finished product roll once wound up,
The product was coated with 15 μm of PMP (I) to obtain a product having a total thickness of 30 μm.

Table 1 also shows the results of the same seepage rust as in Example 1.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location B65D 81/34 B65D 81/34 U

Claims (3)

(57) [Claims] 1. Poly-4-methyl-melting point of 220 to 245 ° C.
1-pentene layer (A), melting point 190 to 230
The intermediate layer (B) made of poly-4-methyl-1-pentene at a temperature of ° C. and the layer (C) made of paper, and the poly-4-methyl-1-pentene of the layer (B) is added to the layer (A). A laminated film or sheet having a lower melting point than the poly-4-methyl-1-pentene used. 2. The thickness (A) / (B) / (C) of each layer constituting said laminated film or sheet is 1 to 2000 μm / 1.
The laminated film or sheet according to claim 1, wherein the thickness is from 2000 to 2000 µm / 5 to 5000 µm. 3. A carton made from the laminated film or sheet according to claim 1.