JPS6319336B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a composite packaging material suitably used for manufacturing packaging bodies such as food packaging bags, and more specifically, the present invention relates to a composite packaging material that is capable of reducing as much as possible the adsorption and permeation of flavoring components in the contents to be packaged. The present invention relates to a composite packaging material which is suitable for producing packages by thermal bonding. Traditionally, packaging for various foods, soft drinks, etc. has been made using multiple sheets of plastic film or a composite film made by laminating plastic film and metal foil, which is then heat-sealed to form a bag shape. Bags are widely used. However, in conventional packaging bags of this type, the innermost layer is usually made of polyolefin film such as polyethylene, but the aromatic components contained in the contents packaged in the polyolefin film are absorbed. , it is easy to penetrate, and therefore adsorption of flavoring ingredients,
It has been desired to develop a package that can reduce penetration as much as possible. In view of the above circumstances, the present inventors have discovered that it is possible to effectively prevent the adsorption and penetration of flavoring components, and therefore, it can be effectively used for packaging foods etc. that contain a large amount of flavoring components.
As a result of intensive research into composite packaging materials that can be easily manufactured into packages by heat sealing, we have developed one surface layer of the composite packaging material using a specific heat-bondable amorphous copolyester film described below.
The present inventors have discovered that the above object can be achieved by making the copolyester film layer the innermost layer of the package when the package is obtained, and have thus arrived at the present invention. That is, to explain this point in more detail, the inventor of the present invention initially considered using polyethylene terephthalate as a material that prevents the adsorption and penetration of flavoring ingredients, but polyethylene terephthalate has poor heat-sealing properties, and even if heat-sealable However, the impact resistance of the heat-sealed part is weak, making it impractical.Also, some polyesters have a high adsorption of flavoring ingredients, so various studies have been conducted to solve this problem. As a result,
Amorphous copolyester, especially amorphous copolyester obtained by using both terephthalic acid and isophthalic acid as acid components and reacting equimolar amounts of these with glycols, satisfies heat sealability,
In addition, there is little adsorption of flavoring ingredients, and in particular, products using terephthalic acid and isophthalic acid in a molar ratio of 1:1 to 1:4 have extremely high heat sealing strength, making it possible to use packaging that requires thermal bonding. It has been found that this material is extremely suitable as a material for packaging bodies such as bags. Moreover, the above copolyester can minimize the adsorption and penetration of flavoring ingredients, and especially when propylene glycol or pentene glycol is used as the glycol, it can more effectively prevent the absorption and penetration of flavoring ingredients. They have discovered that it is possible to do so, and have completed the present invention. The present invention will be explained in more detail below. The composite packaging material according to the present invention is a composite packaging material made by laminating a plurality of plastic films or a plastic film and a metal foil, and the surface layer of the composite packaging material is formed of an amorphous copolyester film that can be thermally bonded. This is done by thermal bonding of the copolyester films, such as by stacking two copolyester film layers so that the innermost layer of each film is on top of the other, and then heat-sealing the periphery to form a bag shape. A package of an appropriate shape is formed by utilizing the properties of the material. Here, as the copolyester film, it is preferable to use an amorphous film obtained by reacting an acid component mainly consisting of terephthalic acid and isophthalic acid with an alcohol component consisting of glycols in equimolar amounts. By using a seed copolyester, excellent heat sealability and impact resistance can be achieved. In addition, the molar ratio of terephthalic acid and isophthalic acid is 1:1 to 1:
By using a ratio of 4, heat sealability,
Impact resistance can be further significantly increased, and adsorption and penetration of flavoring components can be well prevented. As the terephthalic acid component increases,
The melting point of the resulting copolyester increases, and the impact strength of the heat-sealed portion decreases. Furthermore, when the terephthalic acid component is small, the adsorption of flavoring components is satisfactory, but the impact resistance is reduced. In addition, as an acid component, other acid components other than terephthalic acid and isophthalic acid can be added,
The amount used should be small, and the use of aliphatic dicarboxylic acids such as adipic acid is particularly undesirable. Further, the glycols used for forming the copolyester film include ethylene glycol, propylene glycol, butylene glycol, pentene glycol, cyclohexane dimethylol, etc. One or more of these may be used, but in particular Propylene glycol and pentene glycol having 3 or 5 carbon atoms are preferred; by using glycols mainly composed of propylene glycol or pentene glycol, the melting point of the obtained copolyester can be lowered, and the flavoring component can be lowered. Adsorption and penetration can be more effectively prevented. In addition, when obtaining the above-mentioned copolyester, a lubricant such as a fatty acid amide or a fatty acid metal salt, and others may be further mixed if necessary. The copolyester film used in the present invention is preferably not stretched and the orientation anisotropy is suppressed as much as possible from the viewpoint of heat sealability and impact resistance. In addition, this film thickness is determined by taking into account the dimensions of the bag, the amount of filling, the contents of the filling, etc., but it is usually 15~
It is appropriately selected within the range of 150 μm. The composite packaging material according to the present invention is one in which the copolyester film is used as one surface layer and other materials are laminated, and when a package is manufactured, this copolyester film is used as the innermost layer. Materials include other plastic films,
Metal foil, paper, etc. are used as appropriate. For example, when manufacturing a bag, the copolyester film is used as the innermost layer, and the middle layer is made of aluminum foil or the like.
A composite material in which biaxially stretched polyethylene terephthalate film, nylon film, polypropylene film, paper, etc. are laminated can be used as the outermost layer. In addition, the method of laminating these materials is as follows:
Known extrusion methods, dry laminate methods, etc. can be used alone or in combination. Thus, the composite packaging material of the present invention uses terephthalic acid and isophthalic acid in a molar ratio of 1:1 to 1:4 for one surface layer that should constitute the innermost layer of the package, and is substantially aromatic. A package manufactured using a thermally bondable amorphous copolyester film obtained by reacting an acid component made of a group-based dicarboxylic acid with an alcohol component made of glycols. Even when containing food products, soft drinks, etc. containing flavoring ingredients, the adsorption and penetration of flavoring ingredients can be reduced as much as possible, and these can be accommodated without impairing the quality of the contents. In addition, the material of the present invention can be easily manufactured into packages such as bags by heat sealing. Next, experimental examples will be shown to specifically explain the effects of the present invention. In addition, in the following examples, parts indicate molar parts. Experimental example Using the sample below, its heat sealability,
Impact resistance and adsorption of flavoring ingredients were investigated. The results are shown in the table below.

[Table] The ternary copolyester obtained by reacting the above components was formed into a film with a thickness of 40 μm. Samples Nos. 4 and 5 below were produced in the same manner.

[Table] The heat sealability test is based on JIS-Z-
The test was carried out in accordance with the heat sealing strength test of 1526. In addition, to test the impact resistance, a bag with a length of 15 cm and a width of 10 cm was obtained by heat-sealing both side edges and the lower edge of two films.
cc and dropped from a height of 1.2 m, and evaluation was made based on whether or not there was any damage during heat sealing. 〇...No damage at all △...Some damage ×...Damage In addition, in the fragrance component adsorption test, after putting a limonene aqueous solution in the bag and leaving it for one week at 40℃, the amount of limonene in the limonene aqueous solution was measured. This was done by investigating. 〇... There was almost no decrease in the amount of limonene, and limonene was not adsorbed. ×...A decrease in the amount of limonene was observed, and limonene was adsorbed. The above results are shown in the table below.

[Table] Examples are shown below. Example A composite film was manufactured by dry lamination using the copolyester film of sample No. 1 shown in the experimental example as the bottom layer, and on top of that, a 9 μm aluminum foil and a 12 μm biaxially oriented polyethylene terephthalate were sequentially laminated. . Next, two sheets of this composite film are used, and the copolyester film layer is placed on the inside, and the periphery is heated at 150℃, 2Kg/cm ² ,
A packaging bag having the copolyester film as the innermost layer was prepared by heat sealing for 1 second. An aqueous solution containing a flavoring component mainly composed of limonene was placed in this packaging bag and stored at 40°C for one week, but the adsorption and penetration of the flavoring component into the copolyester film, which is the innermost layer, was extremely low. less,
It was well stored and preserved with almost no change in its flavor. In addition, the heat-seal strength of this packaging bag was investigated in the same manner as in the experimental example, and the results were good.An impact resistance test was also conducted, and the heat-sealed portion did not break. Ta.

Claims (1)

[Scope of Claims] 1. A thermally bondable composite packaging material made by laminating a plurality of plastic films or plastic films and metal foil, one surface layer of which is composed of terephthalic acid and isophthalic acid in a molar ratio of 1. :
A thermally bondable amorphous copolyester film obtained by reacting an acid component consisting essentially of an aromatic dicarboxylic acid and an alcohol component consisting of glycols in a ratio of 1 to 1:4. A composite packaging material characterized by being formed by 2. The material according to claim 1, wherein the glycol is mainly composed of propylene glycol or pentene glycol. 3. The material according to claim 1 or 2, wherein the thermally bondable amorphous copolyester forming one surface layer has a thickness of 15 to 150 μm.