JPS61255856A - Composite packaging material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention is suitable for manufacturing containers such as packaging bags filled with contents containing aromatic ingredients such as foods, soft drinks, and cosmetics. More specifically, regarding composite packaging materials, it is possible to protect the aromatic components contained in the contents by reducing adsorption, permeation, and permeation of the aromatic components in the contents as much as possible, and it is also heat-sealable. The present invention relates to a composite packaging material that can produce packaging containers with high strength and impact resistance.

(Prior art and its problems) Conventionally, packaging containers for articles containing aromatic ingredients such as various foods, soft drinks, and cosmetics have been made using multiple layers of plastic film or metal foil such as aluminum foil. Packaging bags are widely used, which are formed into a bag shape by using a laminated composite film and heat-sealing the required peripheral side edges.

However, the innermost layer of these commonly used packaging bags is usually made of polyolefin resin such as polyethylene or polypropylene, but the innermost layer is usually made of polyolefin resin such as polyethylene or polypropylene. There is a problem that the fragrant components adsorbed and penetrated into the polyolefin resin of the innermost layer, and then permeated through it.Furthermore, if a metal foil is interposed as an intermediate layer to protect the fragrant components, the fragrant components There is a problem in that the so-called delamination phenomenon occurs in which the polyolefin resin layer is peeled off from the metal foil surface by penetrating the metal foil surface.

(Summary of the Invention) In view of the above circumstances, the present inventor has devised a method that can effectively prevent the adsorption and permeation of aromatic components, and that can be applied to foods, soft drinks, cosmetics, etc. that contain a large amount of aromatic components. As a result of extensive research into packaging materials that can be effectively used for packaging and that can be easily manufactured into packaging containers by heat sealing, we have selected a material with a high average molecular weight that forms the innermost layer in contact with the contents of the composite packaging material. By forming a film obtained by mixing a hard polyester resin and a soft polyester resin with a relatively low molecular weight, it prevents the adsorption and penetration of aromatic components, making it suitable for foods, soft drinks, and cosmetics. It has been found that the aromatic components contained in the contents of the products such as the above are not adsorbed and can be well protected.

That is, the present applicant has already filed a patent application filed in 1983 for the same purpose.
As shown in Japanese Patent Application No. 156940, a copolyester made of an aromatic dicarboxylic acid is used in the innermost layer that is in direct contact with the contents, and a copolyester made of an aromatic dicarboxylic acid is used as shown in Japanese Patent Application No. 59-186843. It is proposed that the use of a film made of a mixture of polyamide and polyamide will effectively protect the aromatic components of the product.

However, when packaging containers with a relatively large capacity are manufactured using composite packaging materials using films according to these inventions, the heat sealing strength and impact resistance at the heat sealing part are not necessarily sufficient, and the large packaging containers are It has been desired to develop packaging materials that are more suitable for the production of

Therefore, as a result of further studies, the present inventor found that at least one acid component and at least one component are suitable for forming the innermost layer of a packaging container, especially a relatively large packaging container. A polyester resin [(A) resin] obtained by polycondensation with an alcohol component and having an average molecular weight of 20.000 to 40.000, and
The average molecular weight obtained by cocondensation polymerization of at least one acid component and at least one alcohol component is 5.0.
By using a film obtained by mixing a polyester resin [(B) resin] obtained by polycondensation polymerization of 00 to 20.000, the impact strength of the resulting packaging container is higher than that of the above (A) resin. It was found that the heat-sealing strength of the heat-sealed portion was improved compared to the case where the heat-sealed portion was made of only the heat-sealed portion.

Furthermore, the composite packaging material having this film as the innermost layer is D-
Packaging of packaging containers filled with contents such as soft drinks containing IJ monene, etc., confectionery containing vanillin, etc., oral medicines containing anethole, menthol, etc., cosmetics containing benzaldehyde, cytosyl, etc. The present invention was based on the discovery that it can be suitably used as a material.

The present invention will be explained in more detail below.

(Structure of the Invention) As described above, the composite packaging material of the present invention comprises a polyester resin [(
The innermost layer is a polyester film made of a mixture of A) resin] and a polyester resin having an average molecular weight of 5,000 ((B) resin).

be.

In particular, the present invention provides a composite packaging material suitable for manufacturing a packaging container that can be filled with a content containing an aromatic component and that can protect the aromatic component contained in the content. The material forming the innermost layer in contact with the contents of this composite packaging material has an average molecular weight of 20.000 to 40.000 and contains a small amount (one acid component and at least one alcohol component). A polyester resin obtained by cocondensation polymerization [(A) resin], at least one acid component and at least one alcohol component having an average molecular weight of 5.000 to 20.000. The present invention provides a composite packaging material characterized by using a film obtained by mixing a polyester resin [(B) resin] obtained by cocondensation polymerization with a polyester resin obtained by cocondensation polymerization.

According to the present invention, by using a polyester resin film made of a mixture of the above-mentioned (A) resin and (B) resin as the material forming the innermost layer in contact with the contents, the fragrance contained in the contents can be absorbed. This product effectively prevents the adsorption, permeation, and permeation of sexual ingredients into the packaging material, protects the aroma of the contents, and has high heat-sealing strength in the heat-sealing part and excellent impact resistance. can be manufactured.

Here, the average molecular weight obtained by cocondensation polymerization of at least one acid component and at least one alcohol component forming the innermost layer of the composite packaging material of the present invention is 20.0.
00-40,000, preferably 25,000-35.
000 polyester resin [(A
) resin], the acid component of which is phthalic acid, terephthalic acid,
Polyesters made from aromatic dicarboxylic acids such as isophthalic acid are preferable because they have less adsorption, permeation, and permeation of aromatic components than polyesters made from aliphatic dicarboxylic acids; for example, polyesters such as polyethylene terephthalate, terephthalic acid, isophthalic acid, and ethylene glycol. , ternary condensation obtained by cocondensation polymerization of a total of three components: two acid components such as terephthalic acid, isophthalic acid, and 1,4-dicyclohexane dimetatool, terephthalic acid, isophthalic acid, and propylene glycol, and one alcohol component. Polymerized copolyester, terephthalic acid, 1 acid component such as ethylene glycol/propylene glycol, and 2 alcohol components in total.
Three-way polycondensation copolyester obtained by cocondensation polymerization of components, a total of four components such as two acids and two alcohols, such as terephthalic acid, isophthalic acid, ethylene glycol, and propylene glycol, are cocondensed and polymerized. The resulting four-way condensation copolyester can be used as it is, but among these, polyethylene terephthalate and three-way condensation copolyester of terephthalic acid, isophthalic acid, and 1,4-butanediol are particularly preferred.

In addition, as the relatively low molecular weight polyester resin [(B) resin] with an average molecular weight of 5,000 to be mixed with this, the acid component is terephthalic acid, which is an aromatic dicarboxylic acid, and 1,4-butanediol. Polyester obtained by cocondensation polymerization of one component acid and one component alcohol,
A ternary condensation copolyester obtained by cocondensing two acids such as terephthalic acid, isophthalic acid, and 1,4-butanediol with one component alcohol, or a ternary condensation copolyester obtained by cocondensation polymerization of two components such as terephthalic acid, isophthalic acid, 1,4-butanediol, and one component alcohol, or A quaternary co-condensation polymerized copolyester obtained by co-condensing a total of four components, terephthalic acid and 1,4-butanediol, and ethylene glycol, can be preferably used.
Preference is given to using co-condensation polyesters with 4-butanediol and ternary condensation copolyesters of terephthalic acid, isophthalic acid and 1,4-butanediol.

In this case, the mixing ratio of (A) resin and (B) resin is (
It is desirable to use 5 to 30 parts by weight, particularly 10 to 20 parts by weight, of (B) resin to 100 parts by weight of A) resin. (B
) If the amount of resin is less than 5 parts by weight based on 100 parts by weight of resin (A), adsorption and permeation of aromatic components can be prevented, but the heat sealability and impact resistance strength of the resulting film will be low, and on the other hand, mixing If the ratio exceeds 30 parts by weight, absorption and permeation of aromatic components will increase, film forming processability will be poor, and practicality may become poor.

The film obtained by mixing the resin (A) and the resin (B) is preferably an unstretched film, and its thickness may be determined as appropriate depending on the dimensions of the packaging container used, the type of contents, the filling amount, etc. Usually 10~150μ
m, preferably in the range of 20 to 80 μm.

As mentioned above, the composite packaging material of the present invention has a polyester resin film made of a mixture of (A) resin and (B) resin as the innermost layer, but in this case, the other layers of the composite packaging material are It is possible to use commonly used known materials that are appropriately selected depending on the type of packaging container to be manufactured.

The drawings show an embodiment of the composite packaging material of the present invention, and the composite packaging material shown in FIG. 2 is formed, a film 3 made of the polyester resin is laminated on the polyolefin resin layer 2 either directly or via an adhesive, and a surface layer 4 is laminated on the other side of the metal foil 1. be. Here, the surface layer is a single layer or multiple layers of plastic film such as polyethylene, polypropylene, polyester, or nylon, or paper selected to provide desired properties such as heat resistance, air resistance, light shielding properties, and rigidity. It is a laminated film in which layers are laminated in an appropriate order.

Moreover, FIG. 2 shows an example of a composite packaging material in which metal foil is not laminated.

In addition, when manufacturing a composite packaging material using the various materials mentioned above, in order to form a polyester resin film containing a mixture of (A) resin and CB) resin as the innermost layer, known methods such as An extrusion method in which T-Guy is extruded, or a dry lamination method in which a polyester resin is pre-formed on a film and this is laminated using an appropriate adhesive such as an isocyanate adhesive can be used alone or in combination. can be used to form the innermost layer.

When manufacturing packaging containers such as packaging bags using these composite packaging materials, the polyester resin film of the present invention is folded or overlapped to form the innermost layer, and then the necessary peripheral edges are heat-sealed. , forming a so-called three-sided bag, or inserting the above-mentioned packaging material folded in an inverted V-shape as a bottom wall member into the lower end of the composite packaging material folded or stacked as described above. A self-supporting packaging bag is formed by heat-sealing the circumferential edge to an appropriate shape and width and bonding and sealing the bag. Furthermore, the polyester resin film of the present invention may be formed into a tube shape so as to be the innermost layer, so-called a laminate tube, or other suitable forms of packaging containers may be manufactured.

(Effects of the Invention) As described above, in the composite packaging material of the present invention, the material forming the innermost layer in contact with the contents is 20. OOQ~40.000
5. A polyester resin obtained by polycondensation of at least one acid component and at least one alcohol component, preferably having an average molecular weight of 25.000 to 35.000; 000~20.
A film obtained by mixing a polyester resin obtained by cocondensation polymerization of at least one acid component and at least one alcohol component and having an average molecular weight of 0,000. Because of this, packaging containers manufactured using this material are able to prevent adsorption and penetration of aromatic components as much as possible even when filled with various contents containing a large amount of aromatic components. The material of the present invention protects the aroma of the contents and can be filled without sacrificing quality, and the material of the present invention has excellent heat-sealing properties and good heat-sealing strength, as well as high impact resistance when dropped. This makes it suitable for producing packaging containers with relatively large volumes.

EXAMPLES Hereinafter, the present invention will be specifically explained by showing examples and comparative examples, but the present invention is not limited to the following examples.

(Example/Comparative Example) A biaxially stretched polyester film with a thickness of 12 μm, an aluminum foil with a thickness of 9 μm, and a low-density polyethylene film with a thickness of 50 μm were laminated sequentially from the outside by a dry lamination method using an isocyanate adhesive, and then The innermost layer is shown below (
Composite packaging materials of the present invention (Examples 1 to 4) were produced by laminating 60 μm thick mixed films of A) resin and (B) resin in the proportions shown in Table 1 by extrusion.

For comparison, the innermost layer was a 60 μm J9 low density polyethylene film, a 60 μm thick polyester film, the same <60 I1 m thick polyester and nylon 6
- Mixed film with 6.6 copolymer (mixing ratio 100:
Comparative Example 1-3 was produced by manufacturing a composite material having the same structure except for Comparative Example 1-3.

In this case, as the (A) resin of the polyester resin film forming the innermost layer, a ternary co-condensation copolyester of terephthalic acid/isophthalic acid/ethylene glycol in a ratio of 10:1:l is used, and (B) the resin The ratio is 1:1 of terephthalic acid, isophthalic acid, and 1,4-butanediol.
:2 ternary cocondensation polyester was used. In addition, the polyester film of the comparative example used the same ternary cocondensation polyester as the resin (A).

Next, using these materials, a three-sided bag with a length of 170 m and a width of 30 m was manufactured, and the packaging bag was filled with 200 cc of water in which 0.1% D-limonene was dissolved, and left at 40 degrees Celsius for 48 hours. After that, the amount of limonene remaining in the limonene water was investigated and an aroma component adsorption test was conducted.

■...The amount of remaining limonene is large, and almost no limonene is adsorbed.

O: The amount of remaining limonene is slightly decreased, and some adsorption is observed.

×・・・・・・The amount of remaining limonene is extremely small.
Most of the limonene is adsorbed.

In addition, the heat sealing strength was determined according to the heat sealing strength test of JIS-Z-1526, and the impact resistance test was conducted at 15 degrees vertically.
A three-sided bag with a width of 10 co+ is manufactured, and 200 cc of water is placed inside the bag.
was filled and sealed and dropped from a height of 1.2M to investigate whether there was any damage to the heat-sealed part.

◎・・・・・・No damage to the bag was observed.

○: Slight damage to the bag is observed.

×: Many damages to the bag were observed.

Furthermore, in producing the composite packaging material of the example, (A)
The processability of a mixed resin of the resin and (B) resin was investigated when it was extruded from a T-guidance.

◎・・・・・・Very good film forming properties during extrusion.

O: Draw-down properties are insufficient during extrusion film formation, and some film breakage is observed. ×: Film breakage occurs frequently during extrusion film formation.

The above results are shown in Table 1.

Table 1 Note that the above examples do not limit the present invention,
For example, in order to obtain a mixed film of polyester and polyamide (Comparative Example 3) shown in Japanese Patent Application No. 59-186843, the resin (B) used in the present invention may be further mixed.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are sectional views each showing an embodiment of the present invention. 1... Metal foil, 2... Polyolefin resin layer, 3...
... Copolyester film, 4... Surface layer.

Claims (1)

[Claims] 1. Polyester resin with an average molecular weight of 20,000 to 40,000 and an average molecular weight of 5,000 to 20,000
A composite packaging material characterized in that the innermost layer is a polyester film made of a mixture of polyester resin and polyester resin. 2. Polyester film has an average molecular weight of 20,000~
Claim 1: The product is obtained by mixing 5 to 30 parts by weight of a polyester resin having an average molecular weight of 5,000 to 20,000 to 100 parts by weight of a polyester resin having a molecular weight of 40,000. Composite packaging material as described. 3. Polyester resin with an average molecular weight of 20,000 to 40,000 and an average molecular weight of 5,000 to 20,00
Claim 1 or 2, wherein the acid components constituting the polyester resin of No. 0 are all aromatic dicarboxylic acids.
Composite packaging materials as described in Section. 4. The polyester resin with an average molecular weight of 20,000 to 40,000 is polyethylene terephthalate or a ternary condensation polymerization copolyester of terephthalic acid, isophthalic acid, and ethylene glycol, and the average molecular weight is 5,000.
0 to 20,000, the polyester resin is a co-condensation polyester of terephthalic acid and 1,4-butanediol or a ternary co-condensation copolyester of terephthalic acid, isophthalic acid and 1,4-butanediol. Composite packaging material according to scope 3.