JP2007197072A - Lid material for paper-made container - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lid material for a paper-made container, which has no inconvenience such as curling when a lid is sealed and foaming caused by evaporated water content of a paper. <P>SOLUTION: The paper-made lid material seals an opening part of a paper-made container which has the opening part such as a spout and is obtained by molding a laminated material using a paper as a main material. In this lid material, a barrier thermoplastic resin (12) is laminated on one face of the paper (11) and a plurality of thermoplastic resins (13) are laminated at equal intervals in a bamboo blind-like shape on the other face by extrusion lamination. The gas permeability of the paper on which the thermoplastic resins are laminated in a bamboo blind-like shape is preferably ≥10 seconds and <5,000 seconds by a JIS P8117 method. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lid for a paper container such as a paper cup or a cylindrical paper container, and particularly relates to a lid for a paper container that is free from defects such as curling at the time of lid sealing and foaming due to evaporated water of the paper. Is.

  Conventionally, a lot of inventions and devices have been made with respect to a lid that seals an opening of a paper container mainly made of paper having an opening such as a drinking mouth and is easy to recycle without using aluminum or the like. Yes.

  For example, a lid structure that does not contain a metal such as aluminum foil, and has a structure in which a plastic film is applied to the outside to prevent foaming and curling, and further, fine holes are provided (see Patent Document 1). A lid that does not contain metal such as aluminum foil, and has a configuration in which synthetic paper made of synthetic resin is used as a paper base material in order to prevent punching and prevent curling (see Patent Document 2). A paper whose moisture content is adjusted to 3.4% or less in order to prevent curling and stabilize sealing performance (see Patent Document 3). A base paper container and a thermoplastic sealant film are bonded together with an aluminum powder-containing adhesive so that aluminum is contained as little as possible and can be put on a metal detector (see Patent Document 4). Etc.

The said prior art document is shown.
Japanese Patent Laid-Open No. 2001-2113. Japanese Patent Laid-Open No. 10-324361. JP-A-7-267271. JP 2000-219264 A.

  However, in the invention of Patent Document 1, the process of providing fine holes is difficult on the equipment surface and the processing surface, and the processing speed is difficult to be obtained and the accuracy is lacking. Usually, there is a limitation on the width, which tends to increase costs. There are problems such as.

  In addition, the invention of Patent Document 2 is expensive due to the use of synthetic paper. In addition, the resin is polyethylene or polypropylene and lacks heat resistance. There are problems such as.

  Moreover, it is difficult for the invention of Patent Document 3 to manage the paper moisture content in actual processing due to seasonal factors. There are problems such as.

  In addition, the invention of Patent Document 4 increases the cost of the adhesive by containing aluminum powder. Management of laminate strength is difficult. A separate heat-resistant formulation for ink and varnish without film is required. There are problems such as.

The present invention is a lid that seals an opening of a paper container mainly composed of paper having an opening such as a drinking mouth, and has been made in view of the above-described problems relating to a lid that does not use aluminum or the like. ,
It is an object of the present invention to provide a paper container lid material that is free from defects such as curling at the time of lid sealing and foaming due to evaporated water of the paper.

  The invention of claim 1 of the present invention is a paper lid material for sealing an opening of a paper container obtained by molding a laminated material whose main material is paper having an opening such as a drinking mouth, The cover material is characterized in that a barrier thermoplastic resin is laminated on one side of the paper and a plurality of thermoplastic resins are laminated on the other side at regular intervals by extrusion lamination. The paper container lid.

  Thus, according to the first aspect of the present invention, the lid material is laminated with the barrier thermoplastic resin on one side of the paper, and the thermoplastic resin is evenly spaced by extrusion lamination on the other side. In this case, a plurality of the layers are laminated in a bowl shape, so that it has air permeability and has heat resistance at the time of sealing, printing protection, and water resistance. Further, it is possible to obtain an effect of minimizing curling immediately before sealing by laminating a thermoplastic resin on both sides of the paper.

  According to a second aspect of the present invention, in the first aspect of the invention, the plurality of thermoplastic resins laminated in a bowl shape at equal intervals on the other surface of the paper are formed with the same width. This is a paper container lid.

  Thus, according to the second aspect of the present invention, a plurality of thermoplastic resins laminated in a bowl shape at equal intervals on the other surface of the paper are formed with the same width. Can breathe on average.

  The invention of claim 3 is that in the invention of claim 1 or 2, the air permeability of the paper in which the thermoplastic resin is laminated in a bowl shape is 10 seconds or more and less than 5000 seconds according to JIS P8117 method. This is a paper container lid.

  As described above, according to the invention described in claim 3, the air permeability of the paper in which the thermoplastic resin is laminated in a bowl shape is made breathable by setting it to 10 seconds or more and less than 5000 seconds according to JIS P8117 method. And it can be set as the cover material which has the heat resistance at the time of sealing, printing protection, and water resistance.

  If the air permeability of the paper laminated with the thermoplastic resin is less than 10 seconds, the air permeability is too good to prevent water from entering from the surface (moisture in the atmosphere), and it is 5000 seconds or more. And the loss of moisture at the time of sealing (assuming 160 to 240 ° C.) is poor, and the risk of the lid material foaming increases. Therefore, it is necessary to set the air permeability of the paper laminated in the above-mentioned saddle shape to 10 to 5000 seconds by controlling the interval between the saddle-like laminates.

  According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, the thermoplastic resin laminated in a bowl shape on the paper is a polyethylene terephthalate resin or a polybutylene terephthalate resin. A container lid.

  Thus, according to the invention described in claim 4, water resistance and heat resistance can be imparted by using a polyethylene terephthalate resin or a polybutylene terephthalate resin as the thermoplastic resin laminated in a bowl shape on paper. , Easy peeling and curling prevention can be improved at the time of sealing. A thickness of about 5 to 30 μm is preferably used. If it is less than 5 μm, it is difficult to process, and if it is 30 μm or more, the price of the resin becomes high, which is disadvantageous in cost.

Thus, the lid for paper containers of the present invention, the main material is paper, by laminating a thermoplastic resin in a bowl shape by extrusion lamination on the other side, a barrier thermoplastic resin on the other side, Curling due to shrinkage of paper can be prevented, and heat resistance and air permeability can prevent foaming due to moisture evaporation during sealing. Further, since this lid material is wide and can be continuously produced, the production efficiency is good in actual production, and the lid material is advantageous in terms of cost as compared with the prior art.

The present invention will be described in detail below based on one embodiment.
As shown in FIGS. 1 and 2, for example, the lid for a paper container of the present invention is a paper container obtained by molding a laminated material mainly composed of paper having an opening such as a drinking mouth (20 ) Is a paper lid member (10) for sealing the opening (21).

  The structure of the lid (10) is that a barrier thermoplastic resin (12) is laminated on one side of the paper (11), and the thermoplastic resin (13) is evenly spaced on the other side by extrusion lamination. It is characterized by being stacked in a bowl shape.

As the paper (11) used for the cover material, high-quality paper, medium-quality paper, bleached kraft paper, coated paper and uncoated paper having a basis weight of about ²⁰ to 150 g / m ² can be used. Desirably, a basis weight of about 35 to 100 g / m ² can be preferably used on the curled surface and the strength surface. Furthermore, by using a resin-impregnated, water-resistant internal additive, water-resistant paper having a water resistance of about 0.1 to 10 g / m ^{2 with} Cobb water absorption has dimensional stability due to moisture absorption. Resistance to changes such as curling is obtained, and it can be preferably used.

  The barrier thermoplastic resin (12) laminated on one side of the paper (11) is a sealant layer, polyethylene, polypropylene, polyethylene terephthalate, ethylene / vinyl alcohol copolymer, nylon, silicon oxide thin film deposited polyethylene A single film or a laminate of terephthalate, aluminum oxide thin film-deposited polyethylene terephthalate, aluminum-deposited polyethylene terephthalate, polyacrylonitrile, polybutylene terephthalate, polymethylpentene, and other thermoplastic resin films can be used. The barrier property can be enhanced.

  Lamination of the thermoplastic resin (13) in a bowl shape on the other surface of the paper (11) is made possible by processing the extruder die (D). That is, by providing the resin (11) with and without the resin (a) in the width direction of the paper (11) alternately and continuously, air permeability can be provided, and moisture in the paper at the time of sealing. Evaporation occurs smoothly and can prevent problems such as foaming. Moreover, it is preferable that the space | interval of resin is about 1-5 mm (refer FIG. 3).

  A plurality of thermoplastic resins stacked in a bowl shape at equal intervals on the other surface of the paper may be formed with the same width. The widths of the resin-containing portion (a) and the resin-free portion (b) can be set to the same width or different widths according to the air permeability.

Examples of the thermoplastic resin (13) that can be extruded and laminated include various types of polyolefin resins such as low density polyethylene, medium density polyethylene, high density polyethylene, and polypropylene, polyethylene terephthalate, polybutylene terephthalate, polymethylpentene, nylon, and vinyl. It is possible to use a single layer or two or more types of laminated resins for various resins such as alcohol copolymers. Moreover, it is also possible to use an adhesive primer represented by printing or polyethyleneimine on the paper surface, and these resins function as a protective layer when sealing them.
This method is capable of continuous processing and wide-width processing as compared with the conventional method, and is excellent in productivity.

  Hereinafter, the present invention will be described in detail by way of examples.

A high-quality paper (11) having a basis weight of 80 g / m ² provided with a printing layer was prepared.
Separately, a polyethylene terephthalate film having a thickness of 12 μm and a polyethylene film having a thickness of 30 μm were bonded together by a dry lamination method to prepare a barrier thermoplastic resin film (12) serving as a sealant layer.

  Using an extruder with a die processed, polyethylene terephthalate resin is laminated in a bowl shape to a thickness of 20 μm on the printing layer surface of the previously prepared fine paper (11). Laminated laminate paper was produced.

The paper surface of the laminated paper in which the polyethylene terephthalate resin is laminated in a bowl shape and the polyethylene terephthalate film surface of the previously prepared barrier thermoplastic resin film (12) are opposed to each other and bonded together by a dry laminating method. It consists of a layer structure of cage-like polyethylene terephthalate resin (20 μm) (13) / printing layer / quality paper (80 g / m ² ) (11) / polyethylene terephthalate film (12 μm) / polyethylene film (30 μm) (12) [inside] A tape-shaped lid for a paper container (10) of Example 1 was produced (see FIG. 1).

A lid material having the same configuration as that of Example 1 was prepared except that the cage-like polyethylene terephthalate resin (12) was not provided on the outside, and the paper container lid material of Example 2 was obtained. That is, it is a tape-like lid material having a layer configuration of [outside] printed layer / quality paper (80 g / m ² ) (11) / polyethylene terephthalate film (12 μm) / polyethylene film (30 μm) (12) [inside]. .

In Example 1, instead of the outer cage-like polyethylene terephthalate resin, a lid material in which stretched polyethylene terephthalate film (12 μm) was bonded together by a dry laminating method was prepared, and the paper container lid material of Example 3 was obtained. . That is, [Outside] polyethylene terephthalate film (12 μm) / printing layer / quality paper (80 g / m ² ) (11) / polyethylene terephthalate film (12 μm) / polyethylene film (30 μm) (12) [inside] It is a tape-shaped lid. Note that Example 2 and Example 3 are comparative examples of Example 1.

  The tape-shaped lid materials of Examples 1 to 3 thus produced were punched out to a desired size and at 230 ° C. so as to cover the opening (21) of the lid member of the paper cylindrical container (20). Sealing was performed in an atmosphere of 60 ° C., which is a liquid-filled atmosphere, under conditions of 1 second. The sealing result was as follows.

That is, the lid material of Example 1 can be stably sealed without curling or foaming. (Judgment: ○)
The cover material of Example 2 was found to be free of printing ink, had no film on the outside, and the cover material was curled greatly. (Judgment; x)
With the lid material of Example 3, foaming due to evaporation of moisture was recognized, and a stable lid material seal could not be obtained (judgment: x).

The layer structure of the lid member of the paper cylindrical container (20) is [outside] polyethylene (40 μm) / paper (290 g / m ² ) / polyethylene (55 μm) / polyethylene terephthalate film (12 μm) / aluminum oxide-deposited polyethylene. Terephthalate film (12 μm) / polyethylene (60 μm) [inside].

It is explanatory drawing which shows typically one Example of the laminated constitution of the cover material for paper containers of this invention. It is perspective explanatory drawing which shows one Example of the state before sealing the cover material for paper containers of this invention to the opening part of a paper cylindrical container. It is explanatory drawing which shows typically the state by which a thermoplastic resin is extruded in the shape of a bowl from the extruder which processed the die | dye.

Explanation of symbols

10 ... Lid material 11 ... Paper 12 ... Barrier thermoplastic resin 13 ... Thermoplastic resin 20 ... Paper container, paper cylindrical container 21 ... Opening a ... Resin part b ... Parts without resin D ... Dice

Claims (4)

A paper lid for sealing an opening of a paper container obtained by molding a laminated material mainly composed of paper having an opening such as a drinking mouth,
A barrier thermoplastic resin is laminated on one side of the paper, and a plurality of thermoplastic resins are laminated in an eave-like manner on the other side by extrusion lamination. Characteristic lid for paper containers.   2. The paper container lid according to claim 1, wherein the plurality of thermoplastic resins stacked in a bowl shape at equal intervals on the other surface of the paper are formed with the same width. Wood.   4. The paper container according to claim 1, wherein the air permeability of the paper laminated with the thermoplastic resin is 10 seconds or more and less than 5000 seconds according to JIS P8117 method. Lid material.   The paper container lid according to claim 1, 2 or 3, wherein the thermoplastic resin laminated in a bowl shape on the paper is a polyethylene terephthalate resin or a polybutylene terephthalate resin.

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