JP2736412B2 - Paper container with excellent scent retention properties - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention mainly relates to a box-shaped paper container such as a goebel top type container and a brick type container. [Prior art] A conventional laminated material used for paper containers containing various liquid foods and drinks, tea leaves, spices, etc., has both surfaces composed of a polyolefin-based resin layer, and these polyolefin-based resin layers Is generally formed into various types of paper containers by utilizing the thermal bonding performance of the paper container. [Problems to be Solved by the Invention] By the way, the paper container obtained by using the conventional laminated material in which both surfaces are formed of a polyolefin-based resin layer is a polyolefin-based paper container when the laminated material is obtained. When forming a resin layer or molding a paper container with the laminated material, the polyolefin resin undergoes thermal decomposition to generate volatile components such as aliphatic hydrocarbons, and this volatile component is contained in the paper container. As a result of migrating into the contained filling, not only does the filling have a bad taste or a bad smell, but also the polyolefin resin layer in the laminated material has a flavoring component in the filling. Is also easily absorbed or permeated, so that the flavor of the filling material changes and is easily damaged. In order to improve the above-mentioned drawbacks of the polyolefin-based resin layer, there has been proposed a laminated material in which a polyethylene terephthalate resin layer having a low generation of volatile substances and a good fragrance retention property is provided as an inner surface layer. But
Laminated materials provided with a single layer of polyethylene terephthalate resin layer not only have the disadvantages of poor heat sealing strength and impact strength, but also have a laminate in which the polyethylene terephthalate resin layer is provided as an inner surface layer. Since the polyethylene terephthalate resin layer is harder and more fragile than the polyolefin-based resin layer, the bent portion of the polyethylene terephthalate resin layer and the aluminum foil layer in the base material for the packaging material are used in the bending process of the laminated material. Cracks are easily generated in the liquid crystal panel and the like, which also has a disadvantage such as a cause of liquid leakage. Japanese Patent Application Laid-Open No. 60-48344 describes that the use of a polyester film on which a polyolefin resin layer is laminated as a heat seal layer improves the impact resistance. The fact is that the material has not achieved a sufficient effect because the adhesive strength between the polyolefin-based resin layer and the polyester film is insufficient. On the other hand, the present invention provides a laminated material in which both of the conventional surface layers are composed of a polyolefin-based resin layer, a packaging material having a single layer of a polyethylene terephthalate resin layer, and a polyolefin-based resin layer. It eliminates all the drawbacks of the laminated material and the like having the laminated polyester film as the heat seal layer, so that the filling of the paper container obtained by the laminated material does not cause any taste or odor, and There is no crack in the polyethylene terephthalate resin layer or aluminum foil layer in the laminated material in the bending process when it is molded into a paper container, and, furthermore, with the hot-pressure adhesive molding applied to the conventional laminated material A laminated material having a sufficient thermal adhesive strength is used by completely the same molding means, that is, by a molding means utilizing the thermal bonding ability of the resin layer in the laminated material. It is intended to produce a paper container Te. [Means for Solving the Problems] The paper container of the present invention comprises a resin layer made of a linear saturated polyester resin having a glass transition temperature of 40 ° C. or higher, and a biaxially stretched saturated polyester resin film, which is made of an adhesive polyolefin resin. Or a glass transition point temperature is less than 40 ° C. A laminated resin layer adhered via an adhesive layer made of a linear saturated polyester resin less than 40 ° C., a packaging substrate on which a paper layer is laminated, the laminated resin layer Laminated via an adhesive layer such that the linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or higher is located outside, and a linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or higher in the laminated material. Is a paper container having excellent fragrance retention properties characterized by being formed so as to be the inner surface of the paper container. That is, the paper container of the present invention uses a linear saturated polyester resin having a glass transition point temperature of 40 ° C. or higher for the innermost layer in contact with the content to enhance the fragrance retention performance of the content and form the paper container. In this case, sufficient thermal adhesive strength is obtained. Further, a linear saturated polyester resin having a glass transition point temperature of 40 ° C. or more on the inner surface and a biaxially stretched saturated polyester resin film are formed from an adhesive polyolefin resin or a linear saturated polyester resin having a glass transition point temperature of less than 40 ° C. By bonding the laminated resin layer to a packaging material base material via an adhesive, the delamination strength and impact resistance of the paper container are improved. . The linear saturated polyester resin in the laminated resin layer constituting the paper container of the present invention exhibits excellent aroma performance at a temperature lower than the glass transition temperature. Since the contents of the paper container are usually placed in an atmosphere of less than 40 ° C, the linear saturated polyester resin having a glass transition temperature of 40 ° C or higher is used as the linear saturated polyester resin constituting the paper container. By using, the paper container comes to have excellent fragrance retention properties. In addition, it is preferable that the linear saturated polyester resin is a resin having as low a crystallinity as possible so that excellent thermal adhesive strength can be obtained in the thermal adhesive portion of the paper container of the present invention. A linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or higher is formed of, for example, an alcohol component such as ethylene glycol, propylene glycol, 1,4-butadiol, 1,4-cyclohexanedimethanol and an adipic acid, sebacic acid or the like. Dicarboxylic acid components derived from aliphatic carboxylic acids and aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid and diphenylcarboxylic acid, specifically, ethylene glycol and terephthalic acid, ethylene glycol and isophthalic acid and terephthalic acid, and 1,4- It can be formed using a co-condensation polymer such as cyclohexane dimethanol, isophthalic acid and terephthalic acid, and propylene glycol, isophthalic acid and terephthalic acid. However, the aliphatic dicarboxylic acid component in the acid component is
In the case of a co-condensation polymer having a content of 10% by weight or more, a saturated polyester resin layer made of this co-condensation polymer is not preferable because its fragrance retention performance tends to decrease. As the biaxially stretched saturated polyester resin film in the laminated resin layer, a biaxially stretched film of the same kind of resin as the linear saturated polyester resin having a glass transition temperature of 40 ° C. or higher can be used. Polyethylene terephthalate film is preferred. The adhesive layer for bonding the linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or more and the biaxially stretched saturated polyester resin film has an adhesive polyolefin resin or a linear saturated polyester resin having a glass transition temperature of less than 40 ° C. Use polyester resin. Examples of the adhesive polyolefin resin include polyethylene, ethylene-α-olefin copolymer, polyα-olefin such as polypropylene, polybutene and polyisobutylene, and polydiolefin such as polybutadiene and polyisoprene, or a copolymer thereof. The first ethylene component and a carbonyl group based on, for example, carboxylic acid, carboxylate, carboxylic anhydride, carboxylic ester, carboxylic amide or imide, aldehyde, ketone, etc. alone or cyano (-CN)
Group; hydroxy group; ether group; oxirane ring And a copolymer with one or more ethylenically unsaturated monomers. Specific examples of the ethylenically unsaturated monomers include: A. Ethylenically unsaturated carboxylic acids: acrylic acid, methacrylic acid, maleic acid, fumaric acid,
C. Crotonic acid, itaconic acid, citraconic acid, 5-norbornene-2,3-dicarboxylic acid, etc. B. Ethylenically unsaturated carboxylic anhydrides: maleic anhydride, citraconic anhydride, 5-nobornene-2,3-dicarboxylic anhydride , Tetrahydrophthalic anhydride and the like C. ethylenically unsaturated esters: ethyl acrylate, methyl methacrylate, 2-ethylhexyl acrylate, mono or diethyl maleate,
Vinyl acetate, vinyl propionate, propyl γ-hydroxymethacrylate, ethyl β-hydroxyacrylate,
Glycidyl acrylate, glycidyl methacrylate,
D. Ethylene unsaturated amide or imide: acrylamide, methacrylamide, maleimide, etc. E. Ethylene unsaturated aldehyde or ketone: Acrolein, methacrolein, vinyl methyl ketone, vinyl butyl ketone, etc. Of these, ethylenically unsaturated carboxylic acids and ethylenically unsaturated carboxylic anhydrides are particularly preferred. Linear saturated polyester resins having a glass transition temperature of less than 40 ° C. include, for example, dicarboxylic acids such as terephthalic acid, isophthalic acid and adipic acid, and ethylene glycol, propylene glycol, butylene glycol, pentene glycol, cyclohexane dimethylol and the like. It is obtained by co-condensation polymerization with glycols. The laminated resin layer used in the laminated material of the present invention is a linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or higher, an adhesive polyolefin resin or a glass transition temperature of 40.
It is bonded to a biaxially stretched saturated polyester resin film by an adhesive layer of a linear saturated polyester resin having a temperature of less than 0 ° C., and the bending strength is increased by the properties of the biaxially stretched saturated polyester resin film in the laminated resin layer. The laminate has high mechanical strength, and exhibits excellent mechanical strength, and the laminate has excellent bending strength. The packaging material base material on which the paper layer to which the laminated resin layer is adhered is generally a laminated sheet formed of an Al foil, a paper layer, a polyolefin-based resin layer, or the like. In addition, the adhesion between the laminated resin layer and the packaging material base material on which the paper layer is laminated is, for example, the above-mentioned adhesive polyolefin-based resin, a linear saturated polyester having a glass transition temperature of less than 40 ° C. This is performed using an adhesive layer made of a resin, an isocyanate-based adhesive, or the like. EXAMPLES Hereinafter, a specific configuration of a laminated material having excellent fragrance retention properties of the present invention will be described with reference to illustrated examples. Example 1 In FIG. 1, one example of the laminated material of the present invention, which is indicated by reference numeral 1 and has excellent fragrance retention properties, is a linear saturated polyester resin having a glass transition temperature of 81 ° C. [Eastman Kodak ( Co., Ltd .: PETG 6763] formed with a thickness of 10
μ, a 10 μ thick adhesive layer 3 made of a linear saturated polyester resin having a glass transition temperature of −20 ° C. [manufactured by Toyobo Co., Ltd .: Byron GM-900], and acid resistance of 400 g / m ² . A packaging material substrate 7 composed of paper 4, an adhesive layer 5 made of a 15 μm thick ionomer resin [Himilan 1652, manufactured by DuPont-Mitsui Polychemicals Co., Ltd.], and an Al foil 6 having a thickness of 7 μm.
Is formed by laminating a laminated resin layer denoted by reference numeral 8. The laminated resin layer 8 is made of a linear saturated polyester resin having a glass transition temperature of 81 ° C. [manufactured by Eastman Kodak Co., Ltd .: PET.
G 6763] and a polyester resin layer 9 having a thickness of 40μ and a biaxially stretched polyethylene terephthalate film 10 having a thickness of 12μ [[Lumirror manufactured by Toray Industries, Inc.] 10] are combined with a linear saturated polyester resin [Toyobo Co., Ltd. Co., Ltd .: Byron GM
−900, glass transition temperature −20 ° C.]. The packaging material substrate 7 and the laminated resin 8 are bonded to each other by the isocyanate-based resin agent layer 12 between the Al foil 6 surface of the packaging material substrate 7 and the biaxially stretched polyethylene terephthalate film 10 surface of the laminated resin layer 8. I have. Comparative Example 1 The thickness of the laminated material 1 in Example 1 was 12
Thus, a laminated material [i] for comparison having a laminated structure in which the biaxially stretched poly (ethylene terephthalate) film 10 was omitted was obtained. Comparative Example 2 In the configuration of the laminated material 1 in Example 1,
A linear saturated polyester resin layer having a glass transition temperature of 81 ° C. and a linear saturated polyester resin layer having a glass transition temperature of −20 ° C., represented by 2,3, were each combined with a low-density polyethylene resin having a thickness of 20 μm [Mitsui Petrochemical ( Co., Ltd .: Mirason 16sp] layer, and the glass transition temperature indicated by reference numerals 9 and 10
81 ° C linear saturated polyester resin layer and glass transition temperature
The thickness of the linear saturated polyester resin layer at 20 ° C
60μ low density polyethylene resin [Mitsui Petrochemical Co., Ltd.
Manufactured: Mirason 16sp] layer to obtain a laminated material [ii] for comparison. [Experiment 1] The aroma retaining performance and the bending workability of each of the obtained laminate of the present invention and the laminate for comparison were tested based on the following methods. Fabrication of Container A pressing line for bending about 1 mm in width as shown by a symbol m from a surface of a base material for a packaging material of the stacking material on a rectangular laminated material indicated by a symbol 20 in FIG. Was formed, the laminated material 20 was folded along the pressing line m1 and the pressing line m2 of the laminated material 20 so that the packaging material base material side became the outer peripheral surface, to form a bag-shaped precursor. Next, the overlapping portion of the one side portion 21 and the other side portion 22 of the laminated material 20 is formed. In the overlapping portion, the surface of the laminated resin layer of the laminated material 20 and the surface of the base material for packaging material are denoted by reference numeral 23. In the marginal area indicated by, the surfaces of the laminated resin layers of the laminated material 20 (that is, the inner peripheral surface layers of the bag-shaped precursor) are thermally welded and bonded, so that the side of the packaging material substrate in each laminated material is An envelope-shaped container having a peripheral surface was formed. Subsequently, after 200 ml of orange juice is filled in the envelope-shaped container, the laminated resin layers of the opening edge 24 of the laminated material 20 constituting the envelope-shaped container (that is, the inner peripheral surface layer). Are sealed by heat welding and bonding, and the obtained sealed package is bent and formed along a pressing line m for bending in the laminated material constituting the package. In the laminated material shown in FIG. 2, a portion denoted by reference numeral L is a front wall portion, a portion denoted by reference symbol M is a rear wall portion, and a portion denoted by reference symbols N and N is a respective side wall portion. A cubic shape was formed in which the portion indicated by X was the upper bottom wall and the portion indicated by Y was the lower bottom wall. Thereafter, the thermally welded edge portion 23 and the other edge portion 24 are bent in one direction, and the portions that protrude from both side walls are further upwardly disposed on the side wall surface, and the lower portion is disposed downwardly. It is indicated by reference numeral 30 in FIG. 3 by bending and bonding the respective packaging material base surfaces of the laminated material (that is, the outer peripheral surface layers of the container) to the bottom wall surface by heat welding. A brick-shaped paper container having a height of 8.5 cm, a width of 6 cm and a depth of 4 cm having such a shape was obtained. After each of the resulting 100 brick-type paper containers was stored in an atmosphere at 20 ° C. for 7 days, a sensory test of the flavor of the orange juice as the filling and observation of the liquid leakage state of the containers were performed. The results are shown in Table 1. [Experiment 2] Each of the obtained laminated material of the present invention obtained as an example and a comparative laminated material were tested for their fragrance retention performance and bending workability based on the following methods. 4. Preparation of Container A rectangular laminated material indicated by reference numeral 40 in FIG. 4 is folded from the surface of the packaging material base material in the inlaid material to a width of about 1 mm as indicated by reference numeral n. After the pressing line is formed, one side edge 41 of the laminated material 40 is bent toward the packaging material base surface side along the pressing line n1, so that the packaging material base surfaces of the laminated material 40 are bonded to each other. An end face treatment for heat fusion and bonding was performed. Further, the laminated material 40 is moved along the pressing lines n2 and n3.
Was folded such that the laminated resin layer side of the laminated material became the inner peripheral surface to form a bag-shaped precursor. Thereafter, one side 42 and the other side 43 of the laminated material 40 are formed.
In the overlapped portion, the packaging material base surface of the laminated material 40 and the laminated resin layer surface are heat-sealed and bonded, and then the pressing lines n1, n2, n
A rectangular tube having a sectional shape as shown in FIG. 5 was formed by using 3, n4, and n5. In FIG. 5, a portion denoted by reference numeral 50 is an overlapping portion of one side 42 and the other side 43 of the laminated material 40. The laminated material 40 is formed of a laminated resin layer. Next, the bending along the pressing lines n6, n7, n8, n9 is formed in a direction opposite to the bending direction along the pressing lines n1 to n5, and the bending along the pressing line n10 is formed. After folding 44 and 45 inward, respectively,
The box is made so that 46 is the outermost surface of the bottom, and heat-sealing and bonding are performed at the overlapped portion. The bottom 47 was formed by attaching and bonding. Next, 1000 ml of orange juice was filled in a rectangular cylindrical container in which the bottom 47 was closed, and further, a pressing line n1
The bending along the pressing lines n1 to n5 is performed in a direction opposite to the bending direction along the pressing lines n1 to n5, and the bending along the pressing line n15 is formed.
After each is folded inward, the parts 51 and 52 form a head with an inclined top, and are heat-sealed and adhered at the overlapping part, and the overlapping part is a surface of the laminated resin layers of the laminated material 40, By forming the container top 53 adhered by heat welding and bonding between the surfaces of the packaging material base material, a shape as indicated by reference numeral 60 in FIG.
A gauber top type rectangular parallelepiped paper container having a height of 20 cm and a height of 20 cm was obtained. After 1000 pieces of each of the obtained goebel top type paper containers were stored in an atmosphere at 20 ° C. for 7 days, a sensory test of the flavor of the orange juice as the filling and observation of the liquid leakage state of the containers were performed. The results are shown in Table 2. [Operation and Effect of the Invention] The laminated material of the present invention having excellent properties of fragrance retention is 40
A saturated polyester resin layer formed of a linear saturated polyester resin having a glass transition temperature of at least
A biaxially stretched saturated polyester resin film is laminated with a paper layer by laminating a laminated resin layer adhered via an adhesive layer of an adhesive polyolefin resin or a linear saturated polyester resin having a glass transition temperature of less than 40 ° C. Various kinds of packaging material base materials are laminated and adhered such that the saturated polyester resin layer in the laminated resin layer is the outermost layer, and when molded into various containers and packaging bags, etc. The laminated material is used such that the base material side for the packaging material becomes the outer peripheral layer, that is, the laminated resin layer side becomes the inner peripheral layer. However, in the laminated material of the present invention having the above-described structure, the saturated polyester resin layer in the laminated resin layer in the laminated material is formed in an atmosphere at a temperature lower than the glass transition temperature of the resin forming the saturated polyester resin layer. Very good fragrance retention performance. Therefore, in the laminated material of the present invention, the container obtained from the laminated material does not cause a change in the flavor or odor of the filling in the packaging bag, and is excellent in maintaining characteristics of the fragrance-retaining component included in the filling. The container becomes a packaging bag. Further, the laminated material of the present invention may be used as a heat seal layer with respect to the saturated polyester resin layer via an adhesive layer of an adhesive polyolefin resin or a linear saturated polyester resin having a glass transition temperature of less than 40 ° C. Since the laminated resin layer obtained by laminating the axially stretched saturated polyester resin film is used, the biaxially stretched saturated polyester resin film in the laminated resin layer has excellent bending strength and overall mechanical strength. In addition, the saturated polyester resin layer having a glass transition temperature of 40 ° C. or more and the biaxially stretched saturated polyester resin film have an adhesive polyolefin resin or a glass transition temperature of 40 interposed therebetween. It is firmly and integrally attached by an adhesive layer made of a linear saturated polyester resin having a temperature of less than ° C. Thus, the laminated material of the present invention has extremely excellent bending workability. In other words, in the laminated material of the present invention, the property of being hard and brittle in the linear saturated polyester resin layer having a glass transition temperature of 40 ° C. or higher, which exhibits excellent fragrance retention performance,
Compensated by a biaxially stretched saturated polyester resin film adhered to the saturated polyester resin layer via an adhesive layer of a polyolefin resin or a linear saturated polyester resin having a glass transition temperature of less than 40 ° C. Therefore, when an Al foil layer is present in the saturated polyester resin layer or the packaging material base material during the bending process, no crack is generated in the Al foil layer or the like, thereby causing liquid leakage. Without packaging bags and containers.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic cross-sectional view showing one embodiment of a laminated material having excellent fragrance retention properties according to the present invention, and FIG. 2 shows a case where a brick type paper container is obtained from the laminated material. Plan view of the laminated material,
FIG. 3 is a perspective view showing the brick-type paper container obtained by using the laminated material shown in FIG. 2 in a state where the brick-type paper container is turned over, and FIG. FIG. 5 is a cross-sectional view of the torso of the gabelle top type paper container obtained by the laminated material of FIG. 4, and FIG. 6 is a perspective view of the göbel top type paper container obtained by the laminated material of FIG. 1: Laminated material, 7: Packaging material base material laminated with paper layer, 8: Laminated resin layer, 9: Saturated polyester resin layer with linear saturated polyester resin having a glass transition temperature of 40 ° C or higher ,
10: Biaxially stretched saturated polyester resin film, 11: Adhesive layer made of adhesive polyolefin resin or linear saturated polyester resin having a glass transition temperature of less than 40 ° C.

Continuation of front page    (56) References JP-A-58-166039 (JP, A)                 JP-A-49-32983 (JP, A)                 JP-A-60-68938 (JP, A)                 JP-B-51-19454 (JP, B2)                 Jpn. Showa 55-55407 (Jpn. Showa 56-55)               168342) and the specification attached to the application               Microfilm of the contents of the drawing               (JP, U)                 Japanese Utility Model Application No. 59-200170 (Japanese Utility Model Application Showa 61-               115626) and the specification attached to the application               Microfilm of the contents of the drawing               (JP, U)

Claims (1)

(57) [Claims] A resin layer of a linear saturated polyester resin having a glass transition point of 40 ° C. or higher, and a biaxially stretched saturated polyester resin film, made of an adhesive polyolefin resin or a linear saturated polyester resin having a glass transition point of less than 40 ° C. The laminated resin layer adhered via the adhesive layer, the packaging substrate on which the paper layer is laminated, the glass transition temperature of the laminated resin layer is a linear saturated polyester resin layer of 40 ℃ or more. Laminated via an adhesive layer so as to be on the outside, and a linear saturated polyester resin layer having a glass transition point temperature of 40 ° C. or higher in the laminated material is formed so as to be on the inner surface of the paper container. Paper container with excellent fragrance retention properties.