KR100203737B1 - Method for forming a vacuum bag molding sheet - Google Patents

Abstract

The present invention provides a material composition of a vacuum forming sheet which improves impact resistance and whitening phenomenon by melt-mixing an alpha olefin resin polymerized using a single-site catalyst with a polypropylene resin, a method of manufacturing the sheet, and a container thereof It relates to a packaging material.

A first feature of the present invention is a material composition of a vacuum molding sheet prepared by melt-blending 7 to 200 wt% of an alpha olefin resin polymerized using a single-site catalyst in a sheet using a polypropylene resin, to a polypropylene resin, The sheet is formed by a T-die extrusion or casting method of the sheet of claim 1 of the first aspect of the second aspect, and the third feature is a vacuum manufactured using the sheet of claim 1 of the first aspect. It is a molded container, The 4th characteristic is the packaging material which used the container of Claim 3 of the said 3rd characteristic for liquid, paste form, and fluidized product.

Description

Material composition of the sheet for vacuum forming, manufacturing method of the sheet, container thereof and packaging material thereof

1 is a front view of a container according to the present invention.

2 is a side view of a container according to the present invention.

* Explanation of symbols for main parts of the drawings

1: container

The present invention relates to the material composition of a vacuum forming container capable of simultaneously forming the container and filling the contents.

To be more specific, an alpha olefin-based resin polymerized using a single site catalyst is mixed with a polypropylene resin to make a sheet, and then a container molding and contents using a vacuum molding method. The container molding using polypropylene material which can be filled at the same time improves the whitening phenomenon and impact resistance which are disadvantages of this container.

In the detergent, cosmetics, and food businesses, competition is intensifying due to the increase in competitors and the entry of foreign products into Korea due to the opening of the domestic market. In this competition, the cost of products is a very important factor. In addition, packaging materials account for a large portion of these costs, and companies continue to reduce cost of packaging materials as well as contents.

Currently, domestic companies use refill bags using standing pouches and paper packs using paper board carton packs to reduce the cost of container packaging and reduce the difference to consumers. It is insignificant and there is a problem that usability and productivity are very weak compared to container products.

Recently, in Europe, a sheet of a rolled sheet is vacuum-formed and the top of the contents is filled and heat-sealed, and thus a packaging container of a vacuum forming method having high productivity and low packing cost has been developed and put into practical use. MIGROS's dish detergent, PLUS.

However, since this vacuum forming container (hereinafter referred to as a bottle pack) is made of polypropylene resin as a container molding material, the impact resistance is weak at low temperatures, and whitening occurs during external impact, resulting in dirty appearance. There is a problem.

Generally, in order to improve the impact resistance of polypropylene, a certain ratio of polyethylene is mixed with polypropylene, which is a main material, or a propylene-ethylene block copolymer (Propylene-Block-Ethylene Copolymer) is used. .

To explain the cause of the whitening phenomenon, crystalline plastics such as polypropylene have excellent stereoregularity, and when the external impact is applied, the cracking occurs after the crazing phenomenon. Sliding together and causing deformation, this crazing phenomenon is observed with the naked eye.

Therefore, the present inventors have improved the phenomena and impact resistance of the above problems and continued research, the polypropylene mixed molding of the alpha-olefin-based resin polymerized using a single site catalyst (single site catalyst) It has been found that the occurrence of whitening can be suppressed while improving the impact resistance of the polypropylene container.

TECHNICAL FIELD This invention relates to the material composition of the sheet | seat for vacuum forming manufactured by melt-blending 7-20 weight% of alpha olefin resin superposed | polymerized using the single site catalyst in the sheet | seat using a polypropylene resin.

According to the present invention, a bottle pack manufacturing roll manufactured by T-die or casting method of a resin obtained by mixing a polypropylene resin and a polymerized alpha-olefin-based resin polymerized using a single site catalyst is produced. The material composition of a state sheet and the container shape | molded using this sheet are provided, and the occurrence of the whitening phenomenon which is a problem of the container shape | molded using polypropylene sole resin can be suppressed, and an impact resistance can be improved.

The molding method of the manufacturing method of the present invention can be preferably used in the manufacture of bottle packs include vacuum molding method.

As the material composition of the bottle pack sheet capable of simultaneously forming and filling the container 1 according to the present invention, an alpha olefin resin prepared by using a single-site catalyst in polypropylene is mixed and used in an amount of 7 to 20% by weight. .

In this case, when the alpha olefin-based resin polymerized using the single-site catalyst was used at 7 wt% or less, the effect of strengthening impact resistance and suppressing whitening was not sufficiently exhibited. There was no improvement in physical properties with increasing system resin content.

The alpha olefin resin polymerized using the single site catalyst used in the present invention is an ultra low density polyethylene in the form of homo and copolymers having a density of 0.85 to 0.92 g / cm 3 polymerized using a metallocene catalyst. For example, EXACT (brand name) of the US EXXON company is mentioned.

Sheets of the material composition according to the present invention was found to be superior in impact resistance compared to the polypropylene sheet for the bottle pack (Table 1 and Table 2), the effect of suppressing the occurrence of whitening phenomenon (Table 3).

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

Example 1

3 wt% of ultra low density polyethylene resin (EXACT of EXXON, USA) polymerized with a metallocene catalyst was mixed with polypropylene to prepare a sheet having a thickness of 1 mm by a 1 mm method using a T-die method.

Example 2

7 wt% of the ultra low density polyethylene resin polymerized with a metallocene catalyst was mixed with polypropylene to prepare a T-die in the same manner as in Example 1.

Example 3

15 wt% of the ultra low density polyethylene resin polymerized with a metallocene catalyst was mixed with polypropylene to prepare a T-die in the same manner as in Example 1.

Example 4

20 wt% of the ultra low density polyethylene resin polymerized using a metallocene catalyst was mixed with polypropylene to prepare a T-die in the same manner as in Example 1.

Example 5

30 wt% of the ultra low density polyethylene resin polymerized using a metallocene catalyst was mixed with polypropylene to prepare a T-die in the same manner as in Example 1.

Example 6

Two semi-circular containers were formed by using the vacuum forming method with two sheets of Example 1, and the portions except the upper inlet were attached using heat, and then 1 L of dishwashing liquid detergent was filled and the upper inlet was completely sealed. This filled container was prepared.

Example 7

A container 1 was prepared in the same manner as in Example 6 using the sheet of Example 3.

Comparative Example 1

The sheet was prepared in the same manner as in Example 1 using only polypropylene resin.

Comparative Example 2

The same container as in Example 6 was prepared from the sheet of Comparative Example 1.

Experimental Example 1

Sheet Impact Resistance Comparison

A sheet having a thickness of 1 mm was prepared, and the impact strength of each sheet of Examples 1, 3, 4 and Comparative Example 1 was compared using a rheometry dart impact tester (RDT) impact strength tester, and the results are shown in Table 1 below. Indicated. Impact resistance is evaluated to be excellent the higher the impact strength described in Table 1.

As can be seen from the results of Table 1, the sheets of Examples 2, 3, and 4 according to the present invention were found to have superior impact resistance compared to the sheets made of the polypropylene resin of Comparative Example 1.

Experimental Example 2

Vessel Impact Resistance Comparison

1L of dish washing liquid detergent was filled and sealed in the containers of Examples 6, 7 and Comparative Example 2, and 10 containers were added to each box for 48 hours at room temperature and -5 ° C. Dropping was observed to break the container, the results are shown in Table 2 below.

As shown in Table 2, it was confirmed that the container of Example 7 was significantly better in impact resistance than the containers of Example 6 and Comparative Example 2.

Experimental Example 3

Comparison of Whitening Phenomenon

Cut the sheet of Example 3 and Comparative Example 1 horizontally and vertically to a size of 1 × 10 cm, bend both ends of the sheet specimen, press the sheet specimen completely for 10 seconds, and generate whitening phenomenon. Then, the whitening phenomenon was compared, and the results are shown in Table 3 below.

As for the whitening phenomenon, the longer the width | variety shown in Table 3, the more severe whitening phenomenon, and it is evaluated that it is low quality.

As can be seen from the results of Table 3, the sheet of Example 3 according to the present invention can be seen that the whitening phenomenon is significantly improved to less than half the level of the whitening phenomenon compared to the sheet of Comparative Example 1.

Claims (5)

The sheet | seat using polypropylene resin WHEREIN: The material composition of the vacuum molding sheet | seat manufactured by melt-blending 7-20 weight% of alpha olefin resin superposed | polymerized using the single site catalyst to polypropylene resin. The sheet of claim 1, wherein the sheet is formed by a T-die extrusion or casting method. A vacuum forming container manufactured using the sheet of claim 1. A packaging material in which the container of claim 3 is used in a liquid, paste or fluid product. The material composition of the vacuum forming sheet according to claim 1, wherein the single-site catalyst is a metallocene catalyst and the alpha olefin resin is an ultra low density polyethylene resin.