KR19990018332A - Packaging film material made of polyolefin - Google Patents

Abstract

The present invention comprises an inner layer film obtained by melt-kneading a polyolefin-based modifier polymerized using a single-site catalyst, a polyolefin material having a low melting point, and an outer layer film made of a polyolefin material having a high melting point, and is easily recyclable. It relates to a film material.

Description

Packaging film material made of polyolefin

The present invention relates to an environmentally friendly packaging film material composed only of polyolefins and easy to recycle after disposal. More specifically, the present invention consists of an inner layer film obtained by melt kneading a polyolefin-based modifier polymerized using a single-site catalyst, a polyolefin material having a low melting point, and an outer layer film of a polyolefin material having a high melting point. This easy vinyl packaging film material.

In the present specification, the packaging peel refers to a film having a thickness of 250 μm or less, which is easy to ground and print.

Since the implementation of the pay-as-you-go system, there has been an increasing demand for the development of packaging containers made of a single material that is easy to reduce the volume of packaging waste and easily recycle. At present, the packaging materials used for easy volume reduction in disposal may be refill bags used in detergents, supplement products for hair cosmetics, or soft packaging films used in food packaging. It is composed of at least two or three kinds of composite materials because of problems in productivity such as performance.

When explaining in more detail the configuration of the currently used film packaging material, the outer layer using a film made of a strong and heat-sealing material such as nylon, polyethylene terephthalate, biaxially stretched polypropylene in consideration of printability, mechanical properties The inner layer is made of low density polyethylene, linear low density polyethylene, ethylene vinyl acetate, or a film prepared by mixing them in consideration of heat resistance and impact resistance. have. In addition, when the material is used alone, there is a problem in that the outer layer material does not have a heat sealing property and thus the film cannot be made into an envelope.

Accordingly, the inventors of the present invention have continuously conducted experiments to solve the problems of the prior art. As a result, the inner layer film obtained by melting and kneading a polyolefin-based modifier polymerized using a single-site catalyst and a polyolefin material having a low melting point and an outer layer of a high melting point polyolefin material When the packaging film is formed of a film, the difference between the melting point of the inner layer and the outer layer is widened, and thus, the heat sealability is improved, and the present invention has been completed by discovering that a polyolefin material alone can produce a pouch packaging such as a refill bag.

The present invention is a laminated film composed of two or more layers, the outer layer is composed of high density polyethylene or linear low density polyethylene, the inner layer is prepared by melt kneading a polyolefin-based modifier polymerized using a single site catalyst to linear low density polyethylene or low density polyethylene. The present invention relates to a laminated film material for packaging, which is configured by manufacturing or using a modifier alone.

That is, the present invention relates to a packaging film material composed of an inner layer and an outer layer of a polyolefin material having a high melting point by melt kneading a polyolefin-based modifier polymerized using a single-site catalyst to a polyolefin material having a low melting point.

As the material that can be used for the packaging film of the present invention, low density polyethylene, linear low density polyethylene, or a mixture thereof may be used as the polyolefin having a low melting point depending on the characteristics or the use required for the packaging film.

In the present invention, a polyolefin-based modifier polymerized using a single-site catalyst is selected and used because the polymerization of the polyolefin-based modifier is carried out using a commonly used Ziegler Natta catalyst. This is because, on the other hand, there is a limitation in reducing the density of the topical resin, whereas in the case of polymerization using a single-site catalyst, ultra-low density of the resin is possible.

That is, since the density of the modifier affects the melting temperature of the resin, the packaging film prepared by using the polyolefin-based modifier polymerized using a single-site catalyst as in the present invention is a packaging film prepared by using another modifier. Compared with the heat sealability is improved.

As such a polyolefin-based modifier polymerized using a single site catalyst, a copolymer of ethylene and alpha olefins prepared using, for example, a single site catalyst disclosed in US Pat. No. 5,055,438 is usually used. Examples include US EXXON EXACT resin, SLP resin of the same company and ENGAGE resin of US DOW.

In manufacturing the packaging film material according to the present invention, a method that can be preferably used includes a co-extrusion inflation method for simultaneously producing an outer layer and an inner layer and a tee die for overlaying the inner layer film after the outer layer film is manufactured. T-die Extrusion or a dry lamination method of adhering both films after manufacturing the inner and outer layers, respectively.

In the film material of the present invention, the polyolefin-based modifier is used in an amount of 10 to 50% by weight based on the polyolefin resin of the inner layer in the case of the nose extrusion inflation method and the dry lamination method. If the modifier is less than 10% by weight, the effect of improving heat sealability is not sufficiently exhibited. If the modifier is used in excess of 50% by weight, blocking may occur due to the sticking of the films. have.

In addition, in the case of the T die extrusion method, when the outer layer and the inner layer film are manufactured and laminated using the adhesive layer, the polyolefin-based modifier may be used in an amount of 10 to 50% by weight relative to the inner layer resin. When the inner layer is overlaid by the T-die extrusion coding method, the polyolefin-based modifier may be used in an amount of 10 to 100 wt% with respect to the inner-layer polyolefin-based resin, which causes blocking phenomenon in the T-die extrusion coating method. Because it is not.

The heat sealability of the packaging film of the present invention prepared according to the above method was found to be superior to the heat sealability compared to the conventional polyethylene laminated film (Table 2.).

Meanwhile, the packaging film prepared according to the present invention may be preferably used as a soft packaging material for foods such as detergents, fabric softeners, refill packaging materials for hair cosmetics, instant foods, seasonings, and the like. It is therefore an object of the present invention to provide a method of using the packaging film of the present invention as such a packaging material.

Hereinafter, the present invention will be described in more detail with reference to the following examples. However, these examples are only for the understanding of the present invention, and in any sense, the scope of the present invention is not limited to these examples.

(Example 1)

A film having a thickness of 50 μm was prepared by inflation blow method by mixing 10 wt% of a polyolefin-based modifier polymerized with a linear low density polyethylene using a single site catalyst.

(Example 2)

A film having a thickness of 50 μm was prepared by an inflation blow method by mixing 20 wt% of the polymerized polyolefin-based modifier using a linear low density polyethylene single site catalyst.

(Example 3)

A film having a thickness of 50 μm was prepared by an inflation blow method by mixing 30 wt% of the polymerized polyolefin-based modifier using a linear low density polyethylene single site catalyst.

(Example 4)

A film having a thickness of 50 μm was prepared by an inflation blow method by mixing 40 wt% of the polymerized polyolefin-based modifier with a linear low density polyethylene using a single site catalyst.

(Example 5)

A film was prepared in the same manner as in Example 1 except that the film was manufactured using only high density polyethylene.

(Example 6)

A film made by the method of Example 1 and a film made by the method of Example 5 were made by a tee die extrusion lamination method, wherein a low density polyethylene was used with a thickness of 20 μm as the adhesive resin.

(Example 7)

The laminated film was manufactured by carrying out the film made with the method of Example 2, and the film made with the method of Example 5 by the same method as Example 6.

(Example 8)

A film made by the method of Example 3 and a film made by the method of Example 5 were carried out in the same manner as in Example 6 to prepare a laminated film.

(Example 9)

The laminated film was manufactured by carrying out the film made by the method of Example 4, and the film made by the method of Example 5 by the same method as Example 6.

(Comparative Example 1)

A film was prepared in the same manner as in Example 1 except that the film was prepared using only linear low density polyethylene.

(Comparative Example 2)

A film having a thickness of 120 μm was prepared in the same manner as in Example 1 using only linear low density polyethylene.

(Comparative Example 3)

A film made by the method of Comparative Example 1 and a film made by the method of Example 5 were carried out in the same manner as in Example 6 to prepare a laminated film.

Experimental Example 1 Comparison of Thermal Properties of Linear Low Density Polyethylene Film

The thermal properties of the modified linear low density polyethylene films of Examples 1 and 3 and the existing linear low density polyethylene films of Comparative Example 1 were analyzed using a differential scanning calorimeter (DSC), and the results are shown in Table 1 below. It was.

In this case, the lower the melting temperature and the endothermic amount, the better the heat sealability of the peel.

Thermal Characteristics Comparison

TABLE 1

As shown in Table 1, the films of Examples 1 and 3 had a lower melting temperature and an endothermic amount than the films of Comparative Example 1, indicating that the film has excellent heat sealability.

Experimental Example 2: Heat Sealability of Laminated Films

Heat sealing tester (Heat Sealing Tester) was used to compare the heat sealability with temperature for each of the laminated films of Examples 6, 7, 8, 9 and Comparative Examples 2, 3 of the present invention, the results are shown in the following table 2 is shown.

At this time, only the temperature of the three elements of heat sealing temperature, time, pressure was changed only, the heat sealing time was 1 second, the pressure was fixed at 2kgf / ㎠.

The heat sealability was visually observed on the surface state of the sealed film according to temperature, and the degree of sealing was sensory evaluated by pulling the sealing area by hand.

Heat seal comparison

TABLE 2

[Evaluation criteria: XX (unsealed), X (sealed seal), ◁ (slightly sealed),

◀ (sealed slightly), ○ (good sealing)

From Table 2, it was confirmed that the laminated films of Examples 6, 7, 8, and 9 were much better in heat sealability than the films of Comparative Examples 2 and 3.

Claims (6)

In a laminated film composed of two or more layers, the outer layer is made of high density polyethylene or linear low density polyethylene, and the inner layer is prepared by melt kneading the modifier using a single site catalyst on a linear low density polyethylene or low density polyethylene resin, or Packaging laminated film material manufactured by using alone. 2. The film material of claim 1, wherein lamination is performed by dry lamination, tea die extrusion coating, or nose extrusion influence method. 3. The film material according to claim 1 or 2, wherein in the case of the co-exposure inflation or dry lamination method, the polyolefin-based modifier contains 10 to 50% by weight of the polyethylene resin in the inner layer. The film material according to claim 1 or 2, which contains 10 to 100% by weight of a polyolefin-based modifier in the case of the thida benefit casting coating method. A method of using the laminated film material defined in claim 1 as a packaging material for laundry detergents, fabric softeners, kitchen detergents, or hair refills. A method of using the laminated film material defined in claim 1 as a food packaging material such as confectionery or seasoning.