KR100270480B1 - Lamination film having heat-sealing peoperties - Google Patents

Abstract

In the present invention, a polypropylene resin is used as the center layer and the surface layer is coextruded on both surfaces thereof to produce a laminated film, wherein one side of the surface layer has a propylene-ethylene copolymer and a propylene-butene air having a melt index of 3 to 10 g / 10 minutes. 0.1 to 1 of nucleating agent and dispersing agent in 100 parts by weight of the resin mixture composed of 30 to 70 parts by weight of the resin selected from the copolymer and the propylene-ethylene-butene copolymer and 70 to 30 parts by weight of the high density polyethylene resin having a melt index of 0.1 to 5 g / 10 minutes. It is characterized by that it is a matte layer made by mixing by weight.

The non-stretched matte laminated film thus prepared has the characteristics of the non-stretched film as well as the characteristic of the matte film at the same time, which not only looks beautiful but also provides heat adhesiveness to the matte layer. It can be used for printing, packaging industry and image products.

Description

Unstretched Matte Laminated Film with Heat Adhesive

The present invention relates to a non-stretched matte laminated film imparting heat adhesiveness, and not only has the characteristics of the non-stretched film and the matte film at the same time, but also has a matte effect upon lamination with other films by imparting thermal adhesiveness to the matte layer. The present invention relates to a non-stretched matte laminated film provided with heat adhesiveness, which is useful for food or medical packaging.

Conventionally, polypropylene film is the most versatile packaging material. It has been used for food packaging, book cover, shopping bag lamination, etc. for industrial and various snacks, but it is possible to accurately grasp the pattern of letters and shopping bags, etc. due to the gloss of the film surface. Not only was it difficult, but it also had a lot of tired eyes.

In order to solve this problem, a method of diffusely reflecting light incident on the surface of a film by developing surface irregularities on one or both sides of the film has been developed. Packages packaged with matt biaxially oriented polypropylene films prepared in this way can clearly show patterns or letters even under intense light, reduce eye strain and add luxury to the package.

In manufacturing matt polypropylene film, a method of imparting irregularities to the surface of the film is a method of blending polyethylene with polypropylene, a method of using an embossing roll by a mechanical method, an etching method by a solvent, and the like. As diverse.

However, the surface irregularities made by the mechanical method is limited to the use that heat is not used because the surface irregularities disappear when heat is applied in a post-processing process such as extrusion coating, so that a sufficient matte effect can not be expressed.

In addition, a film in which an ethylene-propylene block copolymer is laminated and a film obtained by blending a polypropylene with a high density polyethylene, a low density polyethylene, a linear low density polyethylene, and the like have been developed. In order to impart matteness, the matte layer must be thickened, and this results in a drawback in that the total light transmittance is lowered and the pattern and letters of the package are blurred.

In addition, the matte laminated film as described above has the advantages of the stretched film, that is, the optical properties and mechanical strength is improved when the film is stretched as a stretched film, but also has a problem that the tear strength or impact strength is lowered.

However, until now, it is difficult to disperse the resin used in the matte surface layer finely and evenly, and thus, there is a difficulty in providing a matte effect to the unstretched film.

In addition, in the case of the film having a matte layer, there was a problem that the matting effect disappears when laminated with other films.

SUMMARY OF THE INVENTION An object of the present invention is to provide a non-stretched matte film having a stretchability, tear strength, and the like of a non-stretched film by providing a matt effect to the non-stretched polypropylene film.

Another object of the present invention is to provide a non-stretched matte film that can be laminated with other films on the matte layer by preserving the heat adhesiveness to the matte layer, and can preserve the matt effect even when laminated.

1 is a cross-sectional view of a non-stretched matte laminated film including a matte layer imparting heat adhesion.

* Description of the symbols for the main parts of the drawings *

111-Center Layer 112-Matte Layer

113-polished layer

In order to achieve the above object, the non-stretched matte laminated film of the present invention has a polypropylene resin as a center layer and co-extrudes the surface layer on both sides thereof to produce a laminated film, wherein the matte layer has a melt index of 3 to 10 g / Resin mixture consisting of 30 to 70 parts by weight of at least one resin selected from 10 minutes of propylene-ethylene copolymer, propylene-butene copolymer and propylene-ethylene-butene and 70 to 30 parts by weight of a high density polyethylene resin having a melt index of 0.1 to 5 g / 10 minutes. It is characterized by consisting of 0.1 to 1 parts by weight of each of the nucleating agent and dispersant in 100 parts by weight.

The present invention will be described in more detail as follows.

In the present invention, the resin mixture exhibiting a matte effect on the film is used by pelletizing by a master batch method, which is a propylene-ethylene copolymer having a melt index of 3 to 10 g / 10 minutes and a propylene-butene air. 0.1 to 20 parts by weight of a resin mixture comprising 30 to 70 parts by weight of at least one resin selected from a copolymer and a propylene-ethylene-butene copolymer and 70 to 30 parts by weight of a high density polyethylene resin having a melt index of 0.1 to 5 g / 10 minutes. It is made by mixing -1 weight part.

At this time, the propylene-ethylene copolymer which can be used is preferably 2 to 7% ethylene content, and the propylene-ethylene-butene copolymer is preferably 2 to 5% ethylene content and 3 to 10% butene content.

It is preferable that the melt index of such a copolymer is 3 to 10 g / 10 minutes. If the melt index is out of the above range, there is a possibility that a problem occurs during film molding due to poor resin flowability in the extruder.

And, if the content of such a resin is less than 30 parts by weight of the resin mixture, the haze is sufficient, but the total light transmittance is poor and the heat adhesiveness is lowered, and if it exceeds 70 parts by weight, the problem of deterioration of the matte effect may occur. have.

The content of the nucleating agent and the dispersing agent is 0.1 to 1 parts by weight, preferably 0.3 to 0.8 parts by weight based on 100 parts by weight of the resin mixture.

If the content of the nucleating agent and the dispersing agent is less than 0.1 parts by weight, respectively, water waves may be generated in the overall film and may be undispersed. If the content is more than 1 part by weight, cosmetic melting or fish-eye may occur. do.

Co-extrusion of the matte layer made in this way to one surface of the polypropylene core layer used in the manufacture of a conventional packaging material provides a non-stretched matte laminated film of the present invention, wherein the thickness of the matte layer is 10-30% of the total thickness of the film. Preferably, it is 15 to 25%.

If the thickness of the surface layer exhibiting the matte effect is less than 10% of the total thickness of the film, the degree of blurring becomes low, the matting effect is insufficient, and the heat adhesiveness is insufficient, resulting in a high thermal bonding temperature. Although the drawing is good, there is a disadvantage that the total light transmittance is lowered, and the thermal adhesiveness is good, but there is a problem of lowering the mechanical properties of the non-stretched film.

Meanwhile, in order to enhance the visual effect of the surface in the non-stretched matte laminated film, aluminum deposition processing may be performed on the opposite side of the matte layer according to a conventional method, in which the thickness of the deposited film is 50 to 500 kPa, preferably 100 to 300Å is good. If the thickness of the deposited film is less than 50 GPa, the barrier property is lowered. If the thickness is more than 500 GPa, the aluminum layer is more than a predetermined layer, and thus the same effect is seen in the barrier property.

In addition, in the preparation of the unstretched matte laminated film of the present invention, additives usually added during film production may be added. Examples thereof include an antioxidant, an antistatic agent, or a stabilizer that does not impair the characteristics of the present invention. It can be added within the range.

According to the present invention, a matte non-laminated laminated film prepared by extruding a non-drawn film using a matte resin is a film having a cloudiness of 60% or more and a total light transmittance of 90% or more, and can be applied to various food packaging materials, medical packaging materials, and the like. In addition, the appearance is not only beautiful, but also heat-adhesiveness is given to the matte layer, so that the matt effect is preserved even after lamination with other base films.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Example 1

In order to form the core layer, polypropylene resin was placed in an extruder, and the matte surface layer had 55 parts by weight of a propylene-ethylene-butene copolymer having a melt index of 8 g / 10 minutes, an ethylene content of 3% and a butene content of 5%, and a melt index. The thermal adhesiveness of 25 μm thickness was given so that the thickness of the matte surface layer was 20% of the total film thickness by mixing 0.5 parts by weight of the nucleating agent and the dispersing agent with 100 parts by weight of the resin mixture of 45 parts by weight of 2 g / 10 minutes of high density polyethylene resin. A non-stretched matte film was prepared.

The cross section of the produced film is as shown in FIG.

Example 2

In the same manner as in Example 1, a non-stretched matte film provided with heat adhesiveness was prepared, except that a propylene-ethylene copolymer having an ethylene content of 4% was used instead of the propylene-ethylene-butene copolymer.

Comparative Example 1

A film was prepared in the same manner as in Example 1, except that 80 parts by weight of a propylene-ethylene-butene copolymer and 20 parts by weight of a high density polyethylene resin were used as the resin mixture constituting the matt surface layer.

Comparative Example 2

A film was prepared in the same manner as in Example 1 except that a mixture of 20 parts by weight of a propylene-ethylene-butene copolymer and 80 parts by weight of a high density polyethylene resin was used as the resin mixture constituting the matt surface layer.

Comparative Example 3

A film was prepared in the same manner as in Example 1, except that the addition amount of the nucleating agent and the dispersant in the matt surface layer was 0.01 parts by weight, respectively.

Comparative Example 4

A film was prepared in the same manner as in Example 1 except that the addition amount of the nucleating agent and the dispersing agent in the matt surface layer was 10 parts by weight, respectively.

Comparative Example 5

A film was prepared in the same manner as in Example 1, except that the thickness of the matt surface layer was 5% of the total film thickness.

Comparative Example 6

A film was prepared in the same manner as in Example 1, except that the thickness of the matt surface layer was 35% of the total film thickness.

Experimental Example 1

Cloudiness, total light transmittance, glossiness of the matte surface and film appearance of the films prepared according to Examples 1 to 2 and Comparative Examples 1 to 6 were measured, and the results are shown in Table 1 below.

Here, the cloudiness, total light transmittance, and glossiness were measured using a gloss meter and a haze meter of NIPPON DENSHOKU, Japan, using the method of ASTM D1003. Film samples were taken and measured by the presence of a micro-dispersed phase of the resin, fish-eye and foreign matters when visually confirmed by a fluorescent lamp.

Cloudiness (%) Total light transmittance (%) Glossiness of Matte Surface (%) Film appearance Example One 75 92 11 Good 2 77 90 10 Good Comparative example One 40 87 32 Speckle 2 87 73 10 Speckle 3 72 91 10 Speckle 4 82 75 14 Speckle 5 75 86 22 Speckle 6 71 73 5 Good

In the case of the non-stretched matte laminated film according to the present invention from the results of Table 1, the composition and thickness of the matte layer is higher than the case of the present invention outside the scope of the present invention, the haze is high, the total light transmittance is high, the sharpness of the pattern or letters of the package It can be seen that not only can it be improved, but also the appearance of the film is excellent. And, it can be seen that the matte properties are well represented.

On the other hand, using a heat gradient (film, manufactured by TOYO SEIKI Co., Ltd.) according to the above Examples and Comparative Examples to set the pressure 2 atm, heat bonding time of 1.0 seconds to heat-bond the heat-adhesive matt surface layer Thermal adhesion was measured as shown in Table 2 below.

Thermal bonding temperature (℃) Thermal Bond Strength (g / 25mm) Remarks Example One 135 850 In thermal bonding, the pressure of the thermal bonding bar (BAR) is 2㎏ / ㎠ and the thermal bonding time is 1.0 second. 2 155 950 Comparative example One 135 1050 2 50 3 850 4 700 5 500 6 1100

In the case of the matte non-stretched film which can be heat-bonded according to the present invention from the results of Table 2, it can be used by laminating with other base films on the opposite layer of the matte heat-adhesive layer as a film having sufficient matte effect and retaining heat adhesiveness. Therefore, it can be seen that the matting effect is preserved as it is and heat bonding between the matte surface and the matte surface is possible.

As described in detail above, the laminated film according to the present invention has the characteristics of the non-stretched film and the characteristic of the matte film at the same time, even when the other base film is laminated on the matte side by giving heat adhesiveness to the matte layer The effect is preserved, heat sealable and beautiful in appearance, so it can be usefully used as a food packaging material or a medical packaging material.

Claims (5)

In manufacturing a laminated film by using polypropylene resin as a center layer and co-extrusion of the surface layer on both surfaces thereof, One side of the surface layer has 30 to 70 parts by weight of at least one resin selected from propylene-ethylene copolymer, propylene-butene copolymer and propylene-ethylene-butene having a melt index of 3 to 10 g / 10 minutes and a melt index of 0.1 to 5 g / 10 minutes. A non-stretched matte laminated film having heat adhesiveness, characterized in that it is a matte layer formed by mixing 0.1 to 1 parts by weight of each of a nucleating agent and a dispersant in 100 parts by weight of a resin mixture composed of 70 to 30 parts by weight of a high density polyethylene resin. The non-stretched matte laminated film of claim 1, wherein the propylene-ethylene copolymer has an ethylene content of 2 to 7%. The unstretched matt laminated film of claim 1, wherein the propylene-ethylene-butene copolymer has an ethylene content of 2 to 5% and a butene content of 3 to 10%. The unstretched matt laminated film according to claim 1, wherein the haze is 60% or more, the total light transmittance is 90% or more, and the glossiness of the matte layer is 25% or less. The non-stretched matte laminated film having heat adhesiveness according to claim 1, wherein the thickness of the matte layer is 10 to 30% of the total film thickness.