JP2006056545A - Sheet for portion with unsealing notch - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sheet for a sheet with an unsealing notch which is free from any mixture of suspected endocrine disrupting chemicals in food, substantially the same in the dimensional stability as a sheet formed of single polystyrene, formable under a substantially identical condition by the same manufacturing facility of a conventional portion with an unsealing notch using polystyrene, and capable of obtaining the portion with an unsealing notch free from any problems when unsealed. <P>SOLUTION: The sheet for a portion with an unsealing notch consists of a laminate of a base sheet layer with polypropylene resin, polystyrene resin and compatibilizer are arranged, and a coating layer formed of polyolefin resin. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a potion sheet with an opening notch used for an opening notch with a notch for opening, used for milk such as coffee and tea, or gum syrup such as iced tea and ice coffee.

  Endocrine disrupting chemicals (so-called “environmental hormones”) are problematic because they have a major impact on humans as well as wildlife.

  As familiar examples of such endocrine disrupting chemical substances, it is said that monomers in polystyrene used as food containers and oligomers such as dimers and trimers are applicable.

Here, when such polystyrene is used as a raw material for a food container, in order to remove the user's anxiety that the endocrine disrupting chemical substance gradually elutes in the contained food, JP 2000-33976 A, A technique has been proposed in which a coating layer made of a synthetic resin other than a styrene resin such as polyethylene terephthalate is provided inside a polystyrene food container.
JP 2000-33976 A

  However, the technique according to the above Japanese Patent Laid-Open No. 2000-33976 is an excellent technique that can be implemented by slightly changing the manufacturing conditions while maintaining the conventional manufacturing equipment for polystyrene food containers. It has been found that some applications have problems when applied to potion cups.

  In other words, there was no problem with yogurt, jelly and other relatively large items, but there was a big problem when applied to an opening notch with a notch for opening performed with a relatively small portion cup. I understood.

  Here, first, the opening notched portion will be described with an example. FIGS. 1A to 1C illustrate the resin main body portion 1 (formed by vacuum drawing, pressure forming, and deep drawing in combination thereof) of an example A of a portion with an opening notch for milk. .

  1A is a top view, FIG. 1B is a side view, and FIG. 1C is a bottom view. In the figure, 1a is a food container portion, 1b is a cutting tab portion, and 1c is a notch for opening. In this example, the portion is thinner than other portions so that it can be easily bent and cut.

  FIG. 2 is a diagram showing a state in which the food container 1a is sealed by the sealing sheet 2 by heat welding, and the food produced by the producer is usually contained in the sealed food container 1a. Supplied to consumers. 2A is a top view and FIG. 2B is a side view.

  In order to take out the food, first, as shown in FIG. 3 (a), the cutting tab portion 1b is pinched with a finger, bent at the opening notch 1c portion, the cutting tab portion 1b is broken, and then cut off. As shown in FIG. 3B, the tab portion 1b is further lifted to release the sealing by the welding of the sealing sheet 2 sealing the food container portion 1a.

  When Japanese Patent Application Laid-Open No. 2000-33976 is applied to such a portion with an opening notch, the following major problem occurs at the time of opening.

  That is, a polyethylene body 3 of a laminated sheet formed by laminating polystyrene and polyethylene is placed on the inner side of the food container 1a to form a resin body portion of an opening notch portion, which is sealed after containing food. The state sealed with the stop sheet 2 is schematically shown in FIG.

  At this time, even if it is bent at the notch 1c portion for opening and breaking the tab portion 1b for cutting, the cutting is performed in the polyethylene layer in the same manner as shown in FIGS. 3 (a) and 3 (b). Not 3 Thereafter, when the tab portion 1b for cutting is further pulled up as shown in FIG. 4B, the polyethylene layer 3 is pulled up while being in close contact with the sealing sheet 2 as shown in FIG. The food container 1a is not opened. After that, when the cutting tab portion 1b was continued to be pulled up, problems such as spilling, blowing out, or falling out of the food contained in unexpected places occurred.

  The present invention improves the above-described conventional problems, that is, there is no concern about the influence of endocrine disrupting chemicals on the human body, and almost the same conditions in the same manufacturing equipment as the resin main body portion of the conventional opening notched portion. It is an object of the present invention to provide a sheet for a potion with an opening notch that can be molded by the above-mentioned method and that does not cause a problem even when the potion with an opening notch is used.

  In order to solve the above problems, the unnotched potion sheet of the present invention has a base sheet layer in which a polypropylene resin, a polystyrene resin and a compatibilizing agent are disposed, and a coating layer made of a polyolefin resin, as described in claim 1. It is a sheet | seat for potions with an opening notch formed by laminating | stacking.

  The unnotched potion sheet of the present invention has a configuration in which a base sheet layer in which a polypropylene resin, a polystyrene resin and a compatibilizing agent are arranged, and a coating layer made of a polyolefin resin, are laminated. Because there is no fear of mixing endocrine disrupting chemicals into foods, and the dimensional stability is almost the same as that of polystyrene alone sheets, the same production equipment as conventional production equipment for unnotched potions using polystyrene Thus, it is possible to obtain a potion with an opening notch that can be molded under substantially the same conditions and that does not cause a problem even when opened.

  In order to obtain a resin body portion for opening portions with an opening notch using the opening notched portion sheet of the present invention, it is generally based on a vacuum forming method, a pressure forming method, or a vacuum pressure forming method. Since the part has a large deep drawing, a hot plate vacuum forming method, which is a vacuum forming method in which a heating hot plate is used in combination, can be suitably used.

  In addition, at the time of the said shaping | molding, it is necessary to shape | mold so that the coating layer which consists of polyolefin resin of the sheet | seat for opening portions with an opening notch of this invention may become the food container part inside side. At that time, the equipment such as the mold (including the equipment for providing the notch for opening) can be the same as the equipment of the conventional potion with the opening notch using polystyrene resin. At the time of molding, shrinkage after molding is slightly different from that of a sheet made only of polystyrene resin, so that molding can be performed by slightly changing the mold heating conditions (lowering by about 10 to 15 ° C. as a whole).

  The base sheet layer in the opening notched potion sheet of the present invention needs to be provided with a polypropylene resin, a polystyrene resin and a compatibilizing agent. As other components, pigments, rubber components (such as styrene rubber, impact resistance improving components), antioxidants, and the like may be added as long as they are acceptable for food containers.

  In this case, the mass blending ratio of the polypropylene resin and the polystyrene resin is preferably in the range of 5: 5 to 1: 9 (the range includes a boundary value). If it is not within this range, peeling may occur between the coating layer and the base sheet layer when opening the potion, or the manufacturing conditions of the resin body for the notched potion need to be changed significantly, or shrinkage may occur. The rate is greatly changed, and there is a fear that a conventional mold for molding with a polystyrene resin sheet cannot be used.

  The compatibilizing agent arranged in the base sheet layer of the present invention compatibilizes polypropylene resin and polystyrene resin. Such a compatibilizing agent can be obtained from Asahi Kasei Chemicals Corporation or Nippon Oil & Fats Corporation. These polypropylene resin, polystyrene resin and compatibilizer may be kneaded in advance using a kneader, or may be mixed when forming into a sheet. As a compounding quantity of a compatibilizing agent, it is desirable that they are 1 mass part or more and 6 mass parts or less with respect to 100 mass parts of resin components which consist of the said polypropylene resin and polystyrene resin. When the amount is less than 1 part by mass, the polypropylene resin and the polystyrene resin are not compatible with each other, so that a hole is formed at the time of molding, or partial peeling occurs between the base sheet layer and the coating layer when the portion is opened. When the compounding amount of the compatibilizer is more than 6 parts by mass, the texture, rigidity, and formability of the sheet may change, and there may be a problem.

  Furthermore, the thickness of the coating layer is desirably 5 μm or more and 50 μm or less. When it is less than 5 μm, the coating layer is easily broken when a portion container is used. On the other hand, if the thickness of the coating layer exceeds 50 μm, the manufacturing conditions of the resin body for notched portion portions need to be changed significantly, or the shrinkage rate changes greatly, and the conventional molding resin for polystyrene resin sheets There is a possibility that the mold cannot be used, and peeling may occur between the coating layer and the base layer when the portion is opened.

It is necessary for the coating layer to be made of a polyolefin resin because of good adhesion to the base tank. Here, in the present invention, the coating layer is in direct contact with the food,
It does not contain solutes of endocrine disrupting chemicals, can effectively prevent contact with foods containing these contents, and is preferably made of polyethylene and / or polypropylene in consideration of handling properties, moldability, price, and the like. In addition to these resin components, it is possible to add other components, such as antioxidants, that are acceptable as food containers, if necessary.

  On the other hand, it is desirable that the thickness of the base sheet layer is 450 μm or more and 700 μm or less, which is required for a portion sheet with an opening notch.

  The portion sheet with an opening notch according to the present invention having the base sheet layer and the covering layer is formed by coextrusion molding, coextrusion laminating molding, calendar laminating molding, etc., in a state of being laminated at the same time or almost simultaneously with the molding of each layer. can do. In the present invention, the base sheet layer and the coating layer must be directly laminated, and when laminated via an adhesive layer, the manufacturing conditions of the resin body for a portion with a notch need to be significantly changed. Alternatively, the shrinkage rate changes greatly, making it impossible to use a conventional mold for molding with a polystyrene resin sheet. In addition, the structure of the sheet | seat for opening portions with an opening notch of this invention was shown in model in FIG.

  Hereinafter, examples of the potting sheet with an opening notch of the present invention will be specifically described.

  Raw materials are mixed so that the raw material blending ratio (parts by mass) and thickness shown in Tables 1 and 2 are obtained, and the polypropylene resin (abbreviation “PP”, EA7A manufactured by Nippon Polypro Co., Ltd.) and polystyrene resin are mixed by extrusion lamination. (Abbreviation "PS", HF-77, 475D manufactured by PS Japan), compatibilizer (P-2000 manufactured by Asahi Kasei Chemicals) and styrene rubber (abbreviated "SR", TR-2003 manufactured by JSR) A coating layer made of a polyolefin resin (low density polyethylene (abbreviation “PE”, Nippon Polypro LC720) or polypropylene (abbreviation “PP”, Nippon Polypro MA3)) is laminated on the surface of the base sheet made of The sheet | seats 1-14 for a notch with an opening notch were obtained.

  Using these sheets 14, the same equipment as that used in the production of a conventional unsealed portion potion sheet made of polystyrene (conventional) is used. Then, it was sealed with a sealing sheet to obtain a portion with an opening notch. When molding the resin body part, the case where it was possible to carry out under exactly the same conditions as when using a sheet made of polystyrene, which was conventionally used for potions with an opening notch, was changed with respect to molding temperature and molding time. As a result, “○” indicates that a molded product with a good shape was obtained, and the molding temperature and molding time were changed. Although a molded product with a good shape was obtained, the defect rate due to defective shape was from polystyrene. “△” indicates that it is more than twice as high as the conventional case using a sheet, and “×” indicates that a molded product having a good shape was not obtained although the molding temperature and molding time were changed. evaluated.

  In addition, when actually opening the obtained opening notch portion, “◎” indicates that it can be opened without any inconvenience, but there is no defective opening, but there is a partial gap between the base sheet layer and the coating layer. The case where peeling occurred was evaluated as “Δ”, and the case where tearing occurred in the coating layer after opening (the heat-sealed portion at the time of sealing) or a case where opening failure occurred was evaluated as “X”.

  According to Table 1 and Table 2, according to the sheet for opening portions with an opening notch according to the present invention, it can be molded under almost the same conditions in the same manufacturing equipment as the resin body part of the conventional opening notched portion, and the opening notch It can be seen that there is no problem when opening the potion or opening. In the same manner as above, the compatibilizer was changed to Modiper A3170 manufactured by Nippon Oil & Fats Co., Ltd., and investigations were made in the same manner. However, good results similar to those of P-2000 manufactured by Asahi Kasei Chemicals Co., Ltd. were obtained.

  There is no concern about the effects of endocrine disrupting chemicals on the human body, and molding is possible under almost the same conditions in the same manufacturing equipment as the resin body part of a conventional opening notched potion. Since opening is easy and no problem occurs, it can be suitably used in the production of a potion with an opening notch.

It is the figure shown about the resin main-body part 1 of the example A of the opening notch part for milk. (A) It is a top view. (B) It is a side view. (C) It is a bottom view. In the figure, 1a is a food container portion, 1b is a cutting tab portion, and 1c is an opening notch. In this example, the portion is thinner than the other portions so that it can be easily bent and cut. It is a figure which shows the state by which the food container part 1a was sealed by the sealing sheet 2 by heat welding. (A) It is a top view. (B) It is a side view. It is a model figure which shows the procedure which opens the potion with an opening notch concerning the prior art of FIG. (A) It is a figure which shows the state which pinched the tab part 1b for cutting with a finger | toe, bent it by the notch 1c part for opening, and cut off the tab part 1b for cutting. (B) It is a figure which shows the state which raised the tab part 1b for cutting further. It is a model figure for demonstrating the problem which arises when the technique of Unexamined-Japanese-Patent No. 2000-33976 is applied to a potion with an opening notch. (A) It is a figure which shows the state which pinched the tab part 1b for cutting with a finger | toe, bent it by the notch 1c part for opening, and cut off the tab part 1b for cutting. (B) It is a figure which shows the state which raised the tab part 1b for cutting further. It is a figure which shows in model the structure of the sheet | seat for potions with an opening notch which concerns on this invention.

Explanation of symbols

A Example of a portion with an opening notch for milk 1 Resin body part 1a Food container part 1b Cutting tab part 1c Notch for opening 2 Sealing sheet 3 Polyethylene layer

Claims (5)

  1. A potion sheet with an opening notch, wherein a base sheet layer in which a polypropylene resin, a polystyrene resin and a compatibilizing agent are arranged and a coating layer made of a polyolefin resin are laminated.   2. The potion sheet with an opening notch according to claim 1, wherein a mass blending ratio of the polypropylene resin and the polystyrene resin in the base sheet is in a range of 5: 5 to 1: 9.   The thickness of the said coating layer is 5 micrometers or more and 50 micrometers or less, The sheet | seat for opening portions with an opening notch of Claim 1 or Claim 2 characterized by the above-mentioned.   A resin body portion of a portion with an opening notch, wherein a base sheet layer in which a polypropylene resin, a polystyrene resin and a compatibilizing agent are arranged and a coating layer made of a polyolefin resin are laminated.   A potted portion with an opening notch having a resin main body formed by laminating a base sheet layer in which a polypropylene resin, a polystyrene resin and a compatibilizing agent are arranged and a coating layer made of a polyolefin resin.

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