JP2005053541A - Laminate material for paper container, and paper container using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate material for a paper container in which pin holes are hardly generated when a core layer is corrugated, and functions required for a paper container for take-out food such as oil absorption, oil resistance and heat damage resistance are excellent, and a paper container using the material. <P>SOLUTION: The laminate material for the paper container has a three-layer configuration in which a paper layer with a core layer formed of thin paper, a thermoplastic resin layer and a paper layer formed of thin paper are successively laminated in a laminate body in which a face liner layer and a back liner layer are laminated on both sides of the corrugated core layer, and the paper container is formed of the laminate material for the paper container with the face liner layer thereof on the outer side. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a laminated material for paper containers used in the field of food packaging and a paper container using the same.

  Paper containers are used in various packaging fields because they have excellent packaging functions and recyclability. In recent years, many types of paper containers have been used in the field of various types of take-out foods, which are increasing in number. Especially, as a paper container for packaging foods such as fried foods immediately after heating, a single piece of paper or a resin coat formed into a corrugated shape Paper containers are often used that are made of a laminated material in which a front liner layer and a back liner layer are laminated on both sides of a paper core layer and the front liner layer is placed outside. However, the core layer of the above structure has a drawback that pinholes are likely to occur when it is molded into a corrugated shape, and those using oil-resistant coated paper for the surface liner layer of the laminated material wrap the contents, When the oil derived from the contents penetrates into the core layer, the contents can be seen through, and conversely, those using oil-resistant coated paper on the back liner layer will be changed to the contents when the contents are packaged. Volatilization of the contained moisture is prevented by the back liner layer, and moisture is absorbed again into the contents, resulting in inconveniences such as loss of taste, etc., and a laminated material for paper containers that can cope with these problems and the There was a need for a paper container for the take-out used.

  An object of the present invention is for a paper container in which pinholes are less likely to occur when a core layer is formed into a corrugated shape, and various functions required for takeout food paper containers such as oil absorption, oil resistance, and steam resistance are excellent. It is providing a laminated material and a paper container using the same.

  The invention according to claim 1 of the present invention is a laminate in which a front liner and a back liner layer are laminated on both sides of a corrugated core layer, wherein the core layer is a paper layer made of thin paper, a thermoplastic resin layer A laminated material for paper containers, characterized in that it has a three-layer structure in which paper layers made of thin paper are sequentially laminated.

  The invention according to claim 2 of the present invention is a paper container comprising the outer layer of the front liner layer using the paper container laminate material according to claim 1.

  The laminated material for paper containers of the present invention has a three-layer structure in which the core layer is made of a thin paper layer, a thermoplastic resin layer, and a thin paper layer. It is easy to create a micro flute when forming into a corrugated shape, and pinholes do not occur due to pressure, heat, etc. during molding. Furthermore, this paper container made of laminated material for paper containers is excellent in oil absorption, oil resistance, stuffiness, rigidity, concealment of contents, and quality preservation of contents, and takeout paper such as heated food containing oil Ideal as a container.

  The laminated material for paper containers of the present invention and the paper container using the same will be described in detail below along the embodiments.

FIG. 1 is a side sectional view of an embodiment of a laminated material for paper containers according to the present invention. In the thickness direction, a front liner layer (14), a corrugated core layer (10), a back liner layer ( 15) is laminated, and the core layer (10) has a three-layer structure in which paper layers (12) and (13) made of thin paper are laminated on both sides of the thermoplastic resin layer (11), and The crest (10a), the front liner layer (14), and the back liner layer (15) formed into a corrugated shape are bonded via an adhesive (16). In addition, a space (17) is provided between the peaks formed in the waveform. Generally, the shape of the waveform is called a flute.

  The purpose of forming the core layer (10) into a corrugated shape as described above is carried out in order to give sufficient flexibility during the production of the laminated material and to give toughness to the paper container using the laminated material. Therefore, by changing the height of the flute step and the number of steps per 30 cm, it is possible to obtain a product in which the compressibility, shock absorbing property, hardness and the like are appropriately matched with the purpose.

  The thermoplastic resin layer (11) is made of polyethylene, polypropylene, polyamide, ethylene / acrylic acid copolymer, ethylene / methyl acrylate copolymer, ethylene / methyl methacrylate copolymer, polyester, polylactic acid, polyacrylonitrile, or the like. Resin can be used, and the thickness is preferably 3 to 150 μm. When the thickness is less than 3 μm, pinholes are likely to occur when the core layer (10) is formed into a corrugator with a corrugator, and when it exceeds 150 μm, the corrugation suitability is deteriorated and the height of the step is small, and per 30 cm. It is difficult to obtain a flute with a large number of steps (hereinafter referred to as micro flute). Since this layer is provided in the middle of the three-layered middle core layer (10), it has the function of preventing the oil from oozing out when oily contents are packaged.

The thin paper used for the paper layers (12) and (13) preferably has a basis weight of 10 to 150 g / m ² , and by using the basis weight, it becomes easy to make a micro flute. The types of thin paper used for the paper layers (12) and (13) may be the same or different, and are appropriately selected according to the required quality of the contents.

  As the front liner layer (14), coated paper having a surface coated with clay, non-coated paper, or laminated paper obtained by laminating a plastic film on any of the above papers can be used. When producing a paper container, this front liner layer (14) may be outside the paper container, and a printing layer may be laminated thereon.

  The back liner layer (15) is generally made of kraft paper made of kraft pulp, paper with kraft pulp layers laminated on both sides of the waste paper pulp layer, etc. Thus, it is preferable to use paper appropriately provided with functions such as water repellency, oil resistance, water resistance and water absorption.

  As the adhesive (16), a starch paste prepared by mixing a carrier part liquid in which starch is swollen and destroyed with sodium hydroxide with heated water and a main part liquid in which starch is dispersed in low-temperature water together with borax is used. .

  The laminated material for paper containers of the present invention has a three-layer structure in which the core layer (10) is formed by laminating the paper layers (12) and (13) described above on both sides of the thermoplastic resin layer (11). When the contents immediately after heating are packaged by using the laminated material for paper containers by forming into a corrugated shape with the above, a large number of vapors derived from the contents pass through the back liner layer (15). It escapes outside through the space (17) and does not adversely affect the contents. Furthermore, since there is a thermoplastic resin layer (11) in the middle, the front liner layer (14) absorbs moisture and does not lose its waist or stains.

In addition, when oily contents such as fried foods are packaged, the thin paper of the paper layer (13) on the back liner layer (15) side has an action of absorbing oil, without adversely affecting the contents, Further, since the thin paper of the paper layer (12) on the side of the front liner layer (14) does not absorb oil, the rigidity of the core layer (10) can be maintained, and the contents can be concealed without being smeared with oil and becoming transparent. There is no loss of sex.

  The form of the paper container which uses the laminated material for containers of the present invention and has the front liner layer on the outside is not particularly limited, and examples thereof include a folding box and a sticking box.

  Although the laminated material for paper containers of this invention is demonstrated according to a specific Example below, this invention is not limited to these Examples.

Using a low density polyethylene resin as the resin for the paper thermoplastic resin layer (11), and using high quality paper with a basis weight of 30 g / m ² as the paper for the paper layers (12) and (13), A laminated sheet for cores of high-quality paper (basis weight 30 g / m ² ) / low density polyethylene resin (thickness 20 μm) / high-quality paper (basis weight 30 g / m ² ) was prepared. Subsequently, bleached kraft paper having a basis weight of 100 g / m ² was used as the material for the front liner layer (14) and the back liner layer (15), and starch paste was used as the adhesive (16). Using a corrugator with a flute height of 0.6 mm and a center layer (10) with a number of steps of 177/30 cm while creating a front liner layer (14) and back with starch glue on both sides A liner layer (15) was laminated to produce a laminated material for paper containers of the present invention.

Bleached kraft paper with a basis weight of 70 g / m ² is used as the core sheet, and the surface liner layer is composed of bleached kraft paper (basis weight 100 g / m ² ) / low-density polyethylene resin (thickness 20 μm). A laminated material for a paper container for comparison was prepared in the same manner as in Example 1 except that the low-density polyethylene resin surface was laminated with the core layer side.

Bleached kraft paper with a basis weight of 70 g / m ² is used as the core sheet, and the back liner layer is composed of bleached kraft paper (basis weight 100 g / m ² ) / low-density polyethylene resin (thickness 20 μm). A laminated material for a paper container for comparison was prepared in the same manner as in Example 1 except that the low-density polyethylene resin surface was laminated with the core layer side.

Using an extrusion laminating machine, (Table) Coated ball (basis weight 230 g / m ² ) / milk white low density polyethylene resin (containing 30 wt% titanium oxide), 20 μm / quality paper (basis weight 50 g / m ² ) (back) A laminated material for a paper container for comparison in configuration was prepared.

<Evaluation>
While evaluating the workability | operativity at the time of preparation of the laminated material for paper containers of the said Examples 1-4, the difficulty of the pinhole generation | occurrence | production of a core layer, using this laminated material for paper containers, length 150mm x width 100mm x A take-out paper container having a depth of 60 mm was prepared, filled with croquettes immediately after being fried, and evaluated for oil absorption, oil resistance, moisture resistance, content concealment, rigidity, and crispy content. The results are shown in Table 1.

表１の結果より、実施例１の本発明の紙容器用積層材料は作成時の作業性は良好で、中芯層のピンホールも発生し難く、この紙容器用積層材料からなる紙容器の吸油性、耐油性、耐蒸れ性、内容物の隠蔽性、剛性、内容物のクリスピー感も良好であった。一方、実施例２の比較用の紙容器用積層材料は作成時の作業性は悪く、中芯層にピンホールが発生し
易く、この紙容器用積層材料からなる紙容器の耐蒸れ性及び内容物のクリスピー感も不良であった。実施例３の比較用の紙容器用積層材料は作成時の作業性は悪く、中芯層にピンホールが発生し易く、この紙容器用積層材料からなる紙容器の内容物の隠蔽性、剛性、内容物のクリスピー感も不良であった。実施例４の比較用の紙容器用積層材料は作成時に中芯層にピンホールが発生し易く、この紙容器用積層材料からなる紙容器の耐蒸れ性、剛性、内容物のクリスピー感も不良であった。

From the results of Table 1, the paper container laminated material of the present invention of Example 1 has good workability at the time of preparation, hardly causes pinholes in the core layer, and the paper container made of this paper container laminated material The oil absorption, oil resistance, dampness resistance, concealment of contents, rigidity, and crispness of contents were also good. On the other hand, the comparative paper container laminate material of Example 2 has poor workability at the time of preparation, pinholes are likely to occur in the core layer, and the moisture resistance and content of the paper container made of this paper container laminate material The crispy feeling of the thing was also bad. The laminate material for paper containers for comparison in Example 3 has poor workability at the time of preparation, pinholes are likely to occur in the core layer, and the concealability and rigidity of the contents of the paper container made of this laminate material for paper containers The crispy feeling of the contents was also poor. The paper container laminate material of Example 4 is prone to pinholes in the core layer at the time of production, and the paper container made of this paper container laminate material has poor moisture resistance, rigidity, and crispness of contents. Met.

It is a sectional side view of one Example of the laminated material for paper containers of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Core layer 10a ... Peak part 11 ... Thermoplastic resin layer 12, 13 ... Paper layer 14 ... Front liner layer 15 ... Back liner layer 16 ... Adhesive 17 ... Space

Claims (2)

  In a laminate in which a front liner layer and a back liner layer are laminated on both sides of a corrugated core layer, the core layer is formed by sequentially laminating a paper layer made of thin paper, a thermoplastic resin layer, and a paper layer made of thin paper. A laminated material for paper containers comprising a three-layer structure.   A paper container comprising the front liner layer on the outside using the paper container laminate material according to claim 1.

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