JP2004136486A - Label for molding in-mold label, in-mold label biaxially stretched blow-molded article, and its production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a label for molding an in-mold label which enables exact labeling by determined label arrangement making the label adhere to the surface of a stretching blow-molded article firmly at a temperature during biaxially stretching blow molding to prevent the peeling and dislocation of the label during or after stretching blow molding, an in-mold label biaxially stretched blow-molded article, and its production method. <P>SOLUTION: The label for use in molding the in-mold label in the biaxially stretching blow molding of a preform has a substrate and an adhesive layer. The adhesive layer is made of a thermally adhesive material which is softened/melted at the product temperature of the preform during biaxially stretching blow molding and/or a mold temperature to adhere to the surface of the biaxially stretched blow-molded article. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an in-mold label molding label, an in-mold label biaxial stretch blow molded product, and a method for producing the same.
[0002]
[Prior art]
Biaxially stretched blow-molded products such as polyethylene, polypropylene, polyvinyl chloride, polyethylene terephthalate, polyamide, and polystyrene have the advantages of toughness, dimensional and strength stability, and are widely used as packaging containers. I have. Above all, biaxially stretched blow-molded articles made of a saturated polyester resin (PET) represented by polyethylene terephthalate, especially blow-molded bottles are excellent in transparency, surface gloss, chemical resistance and internal pressure resistance, and are generally packaged. Advantageous properties as a container. For this reason, it is widely used in a wide range of fields such as foods and detergents.
[0003]
Conventionally, with respect to a biaxially stretched molded product, a label is attached in a blow mold, and a preform inserted in the blow mold is biaxially stretched and blown so that a biaxially stretched blow molded product of a predetermined shape is obtained. In molding, a so-called in-mold label molding is performed, in which a label is simultaneously attached to the surface of a biaxially stretched blow molded product (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
Japanese Patent Publication No. 5-7266
[0005]
[Problems to be solved by the invention]
However, when the preform is blow-molded during in-mold label molding, the label is moved due to friction of the adhesive layer of the label with the surface of the preform during the blow molding, and the label cannot be accurately labeled at a predetermined position. There is.
[0006]
The object of the present invention is that the label is firmly adhered to the surface of the stretch blow-molded product at the temperature at the time of biaxial stretch blow molding, and the peeling of the label or the displacement of the label does not occur during or after the blow molding. An object of the present invention is to provide an in-mold label molding label, an in-mold label biaxially stretched blow molded product, and a method for producing the same, which enable labeling to be appropriately performed with a predetermined label arrangement.
[0007]
[Means for Solving the Problems]
The invention according to claim 1 solves the problem related to a label for in-mold label molding, and is a label used for in-mold label molding in biaxial stretch blow molding in which a preform is stretch blow-molded. And an adhesive layer, wherein the adhesive layer is made of a heat-adhesive material that is softened and melted at the product temperature and / or mold temperature of the preform at the time of biaxial stretch blow molding and melts and adheres to the surface of the biaxial stretch blow molded product. The gist of the present invention is a label for forming an in-mold label.
[0008]
The in-mold label of the present invention has a heat-adhesive property in which the adhesive layer is softened and melted at the product temperature and / or mold temperature of the preform at the time of biaxial stretch blow molding, and is adhered to the surface of the biaxial stretch blow molded product. Since it is made of a material, the heat-adhesive material softened and melted in the process of blow molding adheres firmly to the biaxially stretched blow molded product without disturbing the stretch of the blow molded resin. It is intended to make it accurate.
[0009]
In the present invention, for the adhesive layer of the label, a heat-adhesive material that is softened and melted at a temperature of 130 ° C. or lower and adheres to the surface of the stretch blow molded article can be used. If the temperature exceeds 130 ° C., for example, the polyethylene terephthalate layer used as the base material or the stretch blow-molded article made of polyethylene terephthalate is undesirably whitened.
[0010]
In the present invention, it is preferable to use a heat-adhesive material that softens and melts at a temperature of 90 to 70 ° C. and adheres to the surface of the stretch blow-molded article for the adhesive layer of the label. In biaxial stretching of polyethylene terephthalate resin, the label is heated in a blow mold at 90 to 70 ° C., blow-molded in the mold, and after blow molding, heat treatment is performed at a temperature lower than the stretching temperature to obtain a dimension. And stabilization of strength. The adhesive layer made of a heat-adhesive material that is softened and melted at a temperature of 90 to 70 ° C. and adheres to the surface of the stretch blow molded article is suitable for in-mold label molding made of polyethylene terephthalate resin.
[0011]
In the present invention, (a) low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer polymerized using a metallocene catalyst, polypropylene, Ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer Coalesced, methylpentene polymer, acid-modified polyolefin resin obtained by modifying polyolefin resin such as polyethylene or polypropylene with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and other unsaturated carboxylic acids, poly (meth) acrylic resin, Thermoplastic polyester (B) unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate or the like having a heat seal layer, (c) ethylene-vinyl acetate copolymer A hot melt adhesive layer containing a coalesced layer, or a heat sealant layer containing (d) an ethylene-vinyl acetate copolymer can be used.
[0012]
In the present invention, a substrate composed of a laminate including a barrier layer can be used. This barrier layer is made of a plastic film such as polyethylene, polypropylene, polyethylene terephthalate, etc., which is coated with (a) an aluminum foil and (b) a metal or metal oxide vapor-deposited layer, for example, silicon oxide-deposited plastic film, aluminum oxide-deposited plastic. Film, aluminum vapor-deposited plastic film, (c) other, polyacrylonitrile-based resin, ethylene-vinyl acetate copolymer saponified material, polyvinylidene chloride film, polyvinylidene chloride coated biaxially stretched plastic film, etc. It is selected and used as appropriate.
[0013]
By using the label for forming the in-mold label including the barrier layer, the lack of barrier properties against gas such as oxygen or carbon dioxide gas in the polyester resin container is compensated, and contents susceptible to oxygen, such as fruit juice, sake, wine, A polyester resin container suitable for packaging of mayonnaise, ketchup and the like, or as a container for carbonated beverages and beer can be provided. In that case, a barrier layer composed of a silicon oxide-deposited plastic film, an aluminum oxide-deposited plastic film, a polyacrylonitrile-based resin, a saponified ethylene-vinyl acetate copolymer, a polyvinylidene chloride film, a polyvinylidene chloride-coated biaxially stretched plastic film, etc. By using the in-mold label for labeling, a polyester resin container having a barrier property can be provided without impairing the transparency of the container.
[0014]
In the present invention, a substrate made of a plastic film of the same quality as the resin constituting the stretch blow-molded article can be used. For example, when the molded article main body is made of polyethylene terephthalate, a silicon oxide-deposited polyethylene terephthalate film is used as a barrier layer, and the printing base material layer laminated on the barrier layer can also be made of polyethylene terephthalate.
[0015]
Due to the difference in shrinkage due to the difference between the material of the biaxially stretched blow molded product and the material of the label by using the label for in-mold label molding with a base material containing a plastic film of the same quality as the resin constituting the stretch blow molded product It is possible to prevent the label from peeling off.
[0016]
Further, the base material has a printing base material layer, and can be configured so that a printing layer can be formed on the printing base material layer. Thereby, beautiful printing can be performed on the container. In addition, the printing base material layer can be omitted according to the use and purpose.
[0017]
Further, in the present invention, the substrate may contain an ultraviolet absorbing layer. This ultraviolet absorbing layer can be formed, for example, by a printing layer containing a salicylic acid ester, benzophenone, benzotriazole, or acrylonitrile ultraviolet absorbing agent.
[0018]
In addition, by using an in-mold label forming label including an ultraviolet absorbing layer as a base material, a packaging container for contents that are deteriorated by ultraviolet rays such as vitamin-containing foods (orange juice) can be formed.
[0019]
In addition, the label for forming an in-mold label of the present invention can be used for in-mold labels of polyethylene, polypropylene, polyvinyl chloride, polyamide, polystyrene, etc. It can be effectively used for the production of a label biaxial stretch blow molded product.
[0020]
Further, the label of the present invention can be peeled from the biaxially stretched blow-molded article body by adding an inorganic filler such as silicone, microcrystalline wax, calcium carbonate, etc. to the adhesive layer of the label to form a weakly adhesive layer. The label can be easily peelable. Thereby, particularly in the case of a polyester resin container, the container main body can be recycled after the label is peeled off from the container main body when the container is discarded.
[0021]
In the label for forming an in-mold label of the present invention, by forming the base material with a transparent resin layer, the in-mold label can be formed without impairing or reducing the transparency of the molded product itself.
[0022]
Claim 14 solves the problem relating to the in-mold label biaxially stretch blow-molded product, and is a biaxially stretched blow-molded product obtained by biaxially stretch-blow-molding a preform. And an adhesive layer, wherein the adhesive layer is made of a heat-adhesive material that is softened and melted at the product temperature and / or mold temperature of the preform during biaxial stretch blow molding and melts and adheres to the surface of the stretch blow molded product. The label for in-mold label molding according to any one of 1 to 13, wherein the adhesive layer softened and melted at the product temperature and / or mold temperature of the preform at the time of biaxial stretch blow molding has a biaxial stretch blow molded product. The gist of the invention relates to an in-mold label biaxially stretched blow-molded article characterized by being bonded to a surface by being bonded thereto.
[0023]
The in-mold label molded product of the present invention includes a substrate made of a transparent resin and an adhesive layer on the body of the container, and the adhesive layer is formed at a product temperature and / or a mold temperature of the preform during biaxial stretch blow molding. An in-mold label made of a heat-adhesive material that softens and melts and adheres to the surface of a stretch blow-molded product is softened at the product temperature and / or mold temperature of the preform during biaxial stretch blow molding. The melted adhesive layer is bonded to the surface of the biaxially stretched blow-molded product by bonding, and the placement of the label on the molded product is accurate. It does not shift with respect to.
[0024]
Claim 15 solves the problem relating to a method for producing an in-mold label biaxially stretch blow-molded article, and comprises a base material made of a transparent resin layer and an adhesive layer, wherein the adhesive layer is a preform at the time of biaxial stretch blow molding. Use an in-mold label formed of a heat-adhesive material that softens and melts at the product temperature and / or mold temperature and adheres to the surface of the stretch blow-molded product, and attaches this label to the blow mold. The preform heated to a temperature suitable for stretching is expanded in a blow molding mold, and is closely attached to the mold wall surface on which the label is mounted, and biaxially stretched and blow molded, and simultaneously with the molded preform. Immobilizing the adhesive layer that has been softened and melted at the product temperature and / or mold temperature of the preform during biaxial stretch blow molding of the label attached to the blow molding mold. In the method for manufacturing a drawn biaxially stretched blow-molded product, prior to biaxially stretch-blown blow molding of the preform, the preform is once cooled to near room temperature after injection molding, then heated to a temperature suitable for stretching uniformly and remains on the preform. SUMMARY OF THE INVENTION The gist of the present invention is a method for producing an in-mold label biaxially stretched blow-molded article, which is characterized by removing a distortion that occurs.
[0025]
In the present invention, prior to the biaxial stretch blow molding of the preform, the temperature of the blow molding die is adjusted to 130 ° C. or lower to heat and melt the adhesive layer of the label, and the preform is brought into close contact with the melted adhesive layer. While biaxially stretch-molding, the placement of the label with respect to the molded product is accurate, and an in-mold label molded product that does not peel off from the label container body or shift with respect to the container body can be manufactured.
[0026]
Further, in the manufacturing method of the present invention, prior to the biaxial stretch blow molding of the preform, the temperature of the blow molding die is adjusted to 90 to 70 ° C. or less, and the adhesive layer of the label is heated and melted. The label is heated in a blow mold at 90 to 70 ° C. by subjecting the preform to close contact with the layer, and the polyethylene terephthalate resin is blow-molded in the mold. A heat treatment is performed at a lower temperature to stabilize the dimensions and strength, so that an in-mold label molded product made of polyethylene terephthalate resin can be obtained.
[0027]
The method for producing an in-mold label biaxially stretched blow-molded article of the present invention can be effectively used for producing an in-mold label biaxially stretched blow-molded article made of polyethylene terephthalate, polypropylene, polyvinyl chloride, polyamide, polystyrene, or the like. It is.
[0028]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a schematic cross-sectional view showing a basic configuration of an in-mold label forming label of the present invention.
[0029]
The label 1 for forming an in-mold label comprises a base material 2 and an adhesive layer 3, and the adhesive layer 3 is made of a heat-adhesive material which softens and melts at 130 ° C. or lower and adheres to the surface of the stretched molded article.
[0030]
Here, (a) low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer polymerized using a metallocene catalyst, polypropylene, ethylene -Vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer Modified polyolefin resins such as poly (meth) pentene polymer, polyethylene or polypropylene, modified with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid and other unsaturated carboxylic acids, poly (meth) acrylic resin, heat Plastic polyester type (B) an unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate, etc., having a heat seal layer, and (c) ethylene-vinyl acetate copolymer. A hot melt adhesive layer containing a coalesced layer, or a heat sealant layer containing (d) an ethylene-vinyl acetate copolymer can be used.
[0031]
The substrate 2 includes a barrier layer, an ultraviolet protection layer, a printing substrate layer, and the like, which will be described in the following description of embodiments of the present invention.
[0032]
FIG. 2 shows a first embodiment of the present invention in which the substrate 2 comprises a barrier layer 4 and a printing substrate layer 5, and a printing pattern layer 6 is provided on the printing substrate layer 5.
[0033]
Each layer of the barrier layer 4 and the printing base material layer 5 can be formed independently by forming a film and dry laminating through an adhesive, or by co-extruding a part or all of the layers. it can. In addition, the printing base material layer 5 can be omitted according to the use and purpose.
[0034]
The barrier layer 4 is made of an unstretched or stretched plastic film, such as polyethylene, polypropylene, or polyethylene terephthalate, coated with (a) an aluminum foil, and (b) a metal or metal oxide deposited layer, for example, silicon oxide deposited and stretched polyethylene terephthalate. Film, Aluminum oxide vapor-deposited stretched polyethylene terephthalate, Aluminum vapor-deposited stretched polyethylene terephthalate film, (c) Others, polyacrylonitrile resin, saponified ethylene vinyl acetate copolymer, polyvinylidene chloride film, polyvinylidene chloride coated biaxially stretched plastic film Etc. A barrier layer having desired performance can be formed by selecting from the above-mentioned barrier materials.
[0035]
The film used as the printing substrate layer 5 is not particularly limited as long as it can be generally used. For example, an unstretched or stretched film such as a polyethylene terephthalate, a polypropylene film, or a nylon film can be used.
[0036]
The use of the in-mold label forming label including the barrier layer 4 compensates for the lack of barrier properties of the polyester resin container with respect to gases such as oxygen and carbon dioxide, and the contents easily affected by oxygen, such as fruit juice, sake, and wine A polyester resin container suitable for packaging of mayonnaise, ketchup and the like, or as a container for carbonated beverages and beer can be provided.
[0037]
In that case, a barrier layer composed of a silicon oxide-deposited plastic film, an aluminum oxide-deposited plastic film, a polyacrylonitrile-based resin, a saponified ethylene-vinyl acetate copolymer, a polyvinylidene chloride film, a polyvinylidene chloride-coated biaxially stretched plastic film, or the like. By using the in-mold label-forming label containing the above, it is possible to provide a polyester resin container having a barrier property without impairing the transparency of the container.
[0038]
In the present invention, the base material 2 can be a plastic film of the same quality as the resin to be biaxially stretch blow-molded. For example, when the molded article main body is made of polyethylene terephthalate, a silicon oxide-deposited polyethylene terephthalate film is used as a barrier layer, and the printing base material layer laminated on the barrier layer can also be made of polyethylene terephthalate.
[0039]
The use of an in-mold label forming label made of a plastic film in which the base material 2 is the same as the resin to be biaxially stretch blow-molded results in a difference in shrinkage due to the difference in the material of the biaxially stretched blow molded product and the material of the label. Peeling of the label can be prevented.
[0040]
FIG. 3 shows a second embodiment of the present invention in which the substrate 2 is composed of the ultraviolet ray preventing layer 7 and the printing substrate layer 5.
[0041]
The ultraviolet absorbing layer 7 is formed by providing a printing layer containing a polysalicylic acid ester, benzophenone, benzotriazole, or acrylonitrile ultraviolet absorbing agent on an unstretched or stretched plastic film such as polyethylene, polypropylene, polyethylene terephthalate, or nylon film. Can be used.
[0042]
By using the label for forming an in-mold label including the ultraviolet absorbing layer 7, a packaging container for contents that are deteriorated by ultraviolet rays such as a vitamin C-containing food (orange juice) can be formed.
[0043]
FIG. 4 shows a third embodiment of the present invention in which the base material 2 comprises a barrier layer 4, an ultraviolet protection layer 7 and a printing base material layer 5.
[0044]
This embodiment provides a label for forming an in-mold label having a barrier property and an ultraviolet ray preventing function.
[0045]
FIG. 5 shows a fourth embodiment of the present invention. The substrate 2 includes a barrier layer 4 and a printing substrate layer 5, and further includes a surface protection layer 8. As the surface protective layer 8, a film of polyethylene, polypropylene, polyethylene terephthalate, or the like can be used.
[0046]
Further, the label of the present invention can be peeled from the biaxially stretched blow-molded article body by adding an inorganic filler such as silicone, microcrystalline wax, calcium carbonate, etc. to the adhesive layer of the label to form a weakly adhesive layer. The label can be easily peelable. Since the label of this embodiment can be peeled off from the container body, especially in the case of a polyester resin container, the container body can be recycled after the label is peeled off from the container body when the container is discarded.
[0047]
Next, examples of the label for forming an in-mold label of the present invention will be described.
[0048]
1) Stretched polypropylene film (printing substrate layer) (30 μm) / polyethylene terephthalate (12 μm) / stretched silicon oxide vapor-deposited polyethylene terephthalate film (barrier layer) (12 μm) / having heat seal layer containing ethylene-vinyl acetate copolymer Stretched polypropylene film (adhesive layer) (30 μm),
2) Polyethylene terephthalate film (12 μm) / Silicon oxide-deposited polyethylene terephthalate film (12 μm) / Heat sealant layer (adhesive layer) containing ethylene-vinyl acetate copolymer (50 μm)
3) Stretched polypropylene film (printing substrate layer (25 μm) / aluminum foil (barrier layer) (15 μm) / stretched polypropylene film (25 μm) having a heat seal layer including an ethylene-acetic acid heat seal layer
4) Stretched polypropylene film (printing substrate layer) (25 μm) / silicon oxide-deposited polyethylene terephthalate film (12 μm) (barrier layer) / stretched polyethylene terephthalate film having a heat seal layer containing an ethylene-acetic acid copolymer (adhesive layer) (25 μm)
5) Stretched polypropylene film (25 μm) / polyethylene terephthalate film (printing substrate layer) (12 μm) / silicon oxide-deposited polyethylene terephthalate film (barrier layer) (12 μm) / stretching with heat seal layer containing ethylene-acetic acid copolymer Polypropylene film (adhesive layer) (25 μm)
6) Stretched polypropylene film (printing substrate layer) (25 μm) / silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / ethylene methacrylic acid copolymer (adhesive layer) (25 μm),
7) Stretched polypropylene film (print substrate layer) (25 μm) / silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / ethylene acrylic acid copolymer (adhesive layer) (25 μm)
8) Stretched polypropylene film (printing substrate layer) (25 μm) / silicon oxide vapor-deposited stretched polyethylene terephthalate film (barrier layer) (12 μm) / hot melt agent layer (adhesion layer) containing ethylene vinyl acetate copolymer (50 μm);
9) Stretched polypropylene film (60 μm) / ethylene methacrylic acid copolymer (adhesive layer) (25 μm),
10) A hot melt agent layer containing an oriented polypropylene film (60 μm) / ethylene-vinyl acetate copolymer (adhesive layer (25 μm).
[0049]
Next, a method for manufacturing the above-described in-mold label biaxially stretched blow-molded article will be described with reference to FIGS. 6 to 9, with reference to an example of in-mold labeling of a molded article made of polyethylene terephthalate.
[0050]
First, a polyethylene terephthalate resin is injection molded to form a flanged bottomed preform. Prior to biaxial stretch blow molding of the preform, the preform is cooled to near room temperature after injection molding, and then uniformly heated to a temperature (90 ° C.) suitable for stretching the polyethylene terephthalate resin. Remove. Thereafter, the preform 15 is guided to the blow molding die 13 as shown in FIG. 7 while being attached to the holding die 12 fixed to the transfer means 11 as shown in FIG. As shown in FIG. 8, biaxial stretch molding is performed by inflating in the blow molding mold 13 and closely contacting the mold wall surface on which the label 1 is mounted. At this time, the adhesive layer of the label 1 is melted at the product temperature of the preform in the stretching step and / or the temperature of the heat treatment step and is thermally bonded to the surface of the molded article. In FIG. 7, reference numeral 14 denotes an extension rod which moves up and down by an air cylinder (not shown). 8 and 9, reference numeral 16 denotes a completed blow molded product.
[0051]
Here, as described above with reference to FIG. 1, the label 1 includes a base made of a transparent resin layer and an adhesive layer laminated on the base, and the adhesive layer includes (a) low-density polyethylene, medium-density Polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer polymerized using metallocene catalyst, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-ethyl acrylate copolymer A polyolefin resin such as ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyethylene or polypropylene is converted to acrylic acid, methacrylic Acid, maleic anhydride, fumaric acid and other unsaturated carbohydrates An acid-modified acid-modified polyolefin-based resin, poly (meth) acrylic resin, thermoplastic polyester-based resin, thermoplastic polyamide-based resin comprising one or more kinds, (b) polyethylene having a heat seal layer, Unstretched or stretched plastic films such as polypropylene and polyethylene terephthalate, (c) a hot melt adhesive layer containing an ethylene-vinyl acetate copolymer, or (d) a heat sealant layer containing an ethylene-vinyl acetate copolymer. Can be applied.
[0052]
In the biaxial stretch blow molding process, the blow air is preferably at a high pressure, but 10 to 25 kg / cm ² And a sufficient bondability is obtained, and no boundary occurs between the portion covered with the label and the portion not covered with the label.
[0053]
Prior to biaxial stretch blow molding, after preform injection molding, once cooled to near room temperature, it is uniformly heated to a temperature suitable for polyester resin stretching, and the distortion remaining in the preform is removed, thereby reducing distortion. Can perform blow molding and adhesion of the label to the surface of the container. In addition, by removing the distortion by heat treatment in a blow molding die after the blow molding, an in-mold label biaxially stretched blow molded product with less distortion and complete joining of the label to the container can be obtained.
[0054]
Prior to the biaxial stretch blow molding of the preform, the temperature of the blow molding die is adjusted to 130 ° C. or less to heat and melt the heat-adhesive material layer of the label. By performing the biaxial stretching molding while closely contacting the reform, the joining between the preform and the label can be ensured.
[0055]
The method for producing an in-mold label biaxially stretched blow-molded article of the present invention is not limited to the production of an in-mold label biaxially stretched blow-molded article of polyethylene terephthalate, but may be polyethylene, polypropylene, polyvinyl chloride, polyamide, polystyrene. It can also be effectively used for the production of in-mold label biaxial stretch blow-molded products.
[0056]
【Example】
(Example 1)
A cup-shaped in-mold label forming container as shown in FIG. 9 was manufactured. The composition of the label for in-mold molding is composed of a stretched polypropylene film (printing substrate layer) (30 μm) / polyethylene terephthalate (12 μm) / stretched silicon oxide vapor-deposited polyethylene terephthalate film (barrier layer) (12 μm) / ethylene-vinyl acetate copolymer. A drawn polypropylene film (adhesive layer) (30 μm) having a heat-seal layer containing the label was placed in a blow mold for forming a cup-shaped container as shown in FIG. Then, the heat seal layer of the stretched polypropylene film having the heat seal layer containing the ethylene-vinyl acetate copolymer was melted.
[0057]
Using a polyethylene terephthalate resin, a preform having a flange and a step below the flange as shown in FIG. 6 was injection molded. After the injection molding of the preform, it was once cooled to near room temperature and then uniformly heated to a temperature of 90 ° C. suitable for stretching the polyester resin, while removing the distortion remaining in the preform.
[0058]
Then, the preform is guided to the above-described blow molding die, expanded in the blow molding die, brought into close contact with the die wall surface on which the label is mounted, and biaxially stretch-molded, and the label adhesive layer, ethylene-acetic acid The melted surface of the stretched polypropylene film having a heat seal layer containing a vinyl copolymer was brought into close contact with a molded article made of polyethylene terephthalate, and the adhesive layer was welded to the surface of the molded article to obtain an in-mold label molded article. In the obtained molded article, the label was firmly adhered to a predetermined position of the body of the molded article, and no peeling was observed. In addition, this molded article allows the contents of the package to be seen through a transparent label, and has an appropriate barrier property by a silicon oxide vapor-deposited stretched polyethylene terephthalate film (12 μm) and is suitable as a milk beverage container. there were.
[0059]
(Example 2)
Similarly, a label having a layer structure of a polyethylene terephthalate film (12 μm) / a silicon oxide-deposited polyethylene terephthalate film (12 μm) / a heat sealing agent layer (adhesive layer) containing an ethylene-vinyl acetate copolymer (50 μm) was used. An in-mold label molded product was obtained in the same manner as in Example 1. In the obtained molded article, the label was firmly adhered to a predetermined position of the body of the molded article, and no peeling was observed. In addition, this molded article was one in which the contents of the package could be seen through a transparent label, and had an appropriate barrier property by a silicon oxide-deposited polyethylene terephthalate film (12 μm) and was suitable as a beverage container. .
[0060]
【The invention's effect】
As described in detail above, the label for in-mold label molding of the present invention is a label used for in-mold label molding in biaxial stretch blow molding for stretch blow molding a preform, and includes a base material and an adhesive layer. The adhesive layer is made of a heat-adhesive material that softens and melts at the product temperature and / or mold temperature of the preform during biaxial stretch blow molding and adheres to the surface of the biaxial stretch blow molded product. In particular, polyethylene terephthalate in-mold labels that are biaxially stretch blow-molded at 90 ° C. or less can be effectively used for the production of biaxially stretched blow-molded articles, and the use thereof is also limited to polyethylene terephthalate in-mold labels. Polyethylene, polypropylene, polyvinyl chloride, polyamide It is capable of utilizing also effectively for the production of in-mold label biaxially stretch blow molded articles such as polystyrene.
[0061]
Further, the in-mold label biaxially stretch blow-molded product of the present invention is a biaxially stretched blow-molded product obtained by biaxially stretch-blow-molding a preform. The layer is formed of a heat-adhesive material which is softened and melted at the product temperature and / or the mold temperature of the preform at the time of biaxial stretch blow molding, and is adhered to the surface of the stretch blow molded product. The adhesive layer softened and melted at the product temperature and / or the mold temperature of the preform at the time of biaxial stretch blow molding is bonded to the surface of the biaxial stretch blow molded product by bonding. This has the advantage that it does not deviate from the container body during molding or peel off from the container body after molding.
[0062]
Further, the method for producing an in-mold label biaxially stretch blow-molded product of the present invention includes a base material and an adhesive layer, and the adhesive layer is softened at a product temperature and / or a mold temperature of the preform during the biaxial stretch blow molding. A preform that uses an in-mold label made of a heat-adhesive material that melts and adheres to the surface of a stretch blow-molded product, and that is mounted in a blow-molding mold and heated to a temperature suitable for stretching Is expanded in a blow molding die, and is closely adhered to a mold wall surface on which the label is mounted, and biaxially stretch blow-molded. At the same time, a label attached to the blow molding die is formed on the preform. The method for producing an in-mold label biaxially stretched blow-molded article in which the adhesive layer softened at the product temperature and / or the mold temperature of the preform at the time of biaxially stretch blow-molded and adhered to the melted adhesive layer. Prior to biaxial stretch blow molding of the preform, after the injection molding of the preform, it is once cooled to near room temperature and then uniformly heated to a temperature suitable for stretching and the distortion remaining in the preform is removed. Therefore, after removing the distortion remaining in the preform before blow molding, the preform is expanded in the blow molding die, and is closely adhered to the mold wall surface on which the label is attached, and then biaxially stretch-molded. It is possible to perform in-mold labeling in a state where no preform and label are completely joined.
[0063]
Further, in the manufacturing method of the present invention, prior to the biaxial stretch blow molding of the preform, the temperature of the blow molding die is adjusted to 130 ° C. or less, and the adhesive layer of the label is heated and melted. By performing biaxial stretch molding while keeping the preform in close contact with the preform, the joining between the preform and the label can be ensured.
[0064]
The method for producing an in-mold label biaxially stretched blow-molded product of the present invention can be effectively used for producing an in-mold label biaxially stretched blow-molded product such as polyethylene terephthalate, polypropylene, polyvinyl chloride, polyamide, and polystyrene. is there.
[Brief description of the drawings]
FIG. 1 is a schematic sectional view showing a basic configuration of an in-mold label forming label of the present invention.
FIG. 2 is a schematic cross-sectional view showing a first embodiment of the label of the present invention.
FIG. 3 is a schematic sectional view showing a second embodiment of the label of the present invention.
FIG. 4 is a schematic sectional view showing a third embodiment of the label of the present invention.
FIG. 5 is a schematic sectional view showing a fourth embodiment of the label of the present invention.
FIG. 6 is a schematic cross-sectional view showing a process of inserting a preform into a blow molding die in the method for producing an in-mold label biaxially stretched blow molded product of the present invention.
FIG. 7 is a schematic cross-sectional view showing a process of extending a preform with an extension rod in the method for producing an in-mold label biaxially stretched blow-molded product of the present invention.
FIG. 8 is a schematic cross-sectional view showing a heat treatment process after a stretching process in the method for producing an in-mold label biaxially stretched blow-molded product of the present invention.
FIG. 9 is a schematic sectional view showing a product obtained by the method for producing an in-mold label biaxially stretched blow-molded product of the present invention.
[Explanation of symbols]
1 label
2 Base material
3 adhesive layer
4 Barrier layer
5 Printing base material layer
6 Printing layer
7 UV protection layer
8 Surface protective layer
11 Transportation means
12 Holding type
13 Blow mold
14 Extension rod
15 Preform
16 Blow molded products

Claims (17)

A label used for in-mold label molding in biaxial stretch blow molding for stretch blow molding a preform, comprising a substrate and an adhesive layer, wherein the adhesive layer comprises a product temperature of the preform at the time of biaxial stretch blow molding and / or Alternatively, a label for forming an in-mold label, comprising a heat-adhesive material which is softened and melted at a mold temperature and adheres to the surface of a biaxially stretched blow-molded product. The label for in-mold label molding according to claim 1, wherein the adhesive layer is made of a heat-adhesive material that is softened and melted at a temperature of 130 ° C or less and adheres to the surface of the stretch blow molded article. The label for in-mold label molding according to claim 1, wherein the adhesive layer is made of a heat-adhesive material that softens and melts at a temperature of 90 to 70 ° C and adheres to the surface of the stretch blow molded article. Thermal adhesive materials are low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, ethylene-α-olefin copolymer, polypropylene, ethylene-vinyl acetate copolymer polymerized using metallocene catalyst , Ionomer resin, ethylene-ethyl acrylate copolymer, ethylene-methyl methacrylic acid copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-propylene copolymer, methylpentene polymer, polyethylene Alternatively, an acid-modified polyolefin resin obtained by modifying a polyolefin resin such as polypropylene with acrylic acid, methacrylic acid, maleic anhydride, fumaric acid or another unsaturated carboxylic acid, poly (meth) acrylic resin, thermoplastic polyester resin, heat Plastic polyamide One or in-mold label forming label according to any one of claims 1 to 3, characterized in that it consists of a plurality of kinds of resin. The in-mold label forming label according to any one of claims 1 to 3, wherein the heat-adhesive material comprises a polyethylene terephthalate film having a heat seal layer or a stretched polypropylene film having a heat seal layer. The in-mold label forming label according to any one of claims 1 to 3, wherein the heat-adhesive material comprises a hot melt adhesive containing an ethylene-vinyl acetate copolymer. The in-mold label forming label according to any one of claims 1 to 3, wherein the heat-adhesive material comprises a heat sealant containing an ethylene-vinyl acetate copolymer. The label for forming an in-mold label according to claim 1, further comprising a barrier layer. The label for forming an in-mold label according to any one of claims 1 to 8, further comprising a base material including a plastic film of the same quality as a resin constituting the stretch blow-molded product. The label for forming an in-mold label according to any one of claims 1 to 9, further comprising a printing base material layer. The label for forming an in-mold label according to any one of claims 1 to 10, further comprising an ultraviolet absorbing layer. The in-mold label molding label according to any one of claims 1 to 11, wherein the label is formed so as to be peelable from a molded product body of a biaxially stretched blow-in molded label molded product. The label for forming an in-mold label according to any one of claims 1 to 3, wherein the substrate comprises a transparent resin layer. A biaxially stretched blow-molded product obtained by biaxially stretch-blow-molding a preform, the body of which is provided with a base material and an adhesive layer. The in-mold label molding label according to any one of claims 1 to 13, wherein the label is made of a heat-adhesive material which is softened and melted at the mold temperature and adheres to the surface of the stretch blow-molded article. The in-mold label biaxial stretching characterized in that the adhesive layer softened and melted at the product temperature and / or the mold temperature of the preform is bonded to the surface of the biaxially stretched blow molded product by bonding. Blow molded product. It comprises a base material and an adhesive layer, and the adhesive layer is made of a heat-adhesive material that softens and melts at the product temperature and / or mold temperature of the preform during biaxial stretch blow molding and melts and adheres to the surface of the stretch blow molded product. Using a label for in-mold label molding, mounting this label in a mold for blow molding, expanding a preform heated to a temperature suitable for stretching in the mold for blow molding, and attaching the label to the mold Biaxially stretch blow-molded in close contact with the wall surface, and at the same time, the product temperature and / or mold temperature of the preform during biaxially stretched blow molding of the label attached to the blow molding die on the molded preform. In a method for producing an in-mold label biaxially stretched blow molded article in which the adhesive layer softened and melted by the step is adhered, the injection of the preform is performed prior to the biaxially stretched blow molding of the preform. Method for producing in-mold label biaxially stretched blow molded article and removing the distortion remaining in the preform while heating to a temperature suitable for uniformly stretching after cooling once to near room temperature after the molding. Prior to the biaxial stretch blow molding of the preform, the temperature of the mold for blow molding is adjusted to 130 ° C. or less to heat and melt the adhesive layer of the label. The method for producing an in-mold label biaxially stretched blow molded article according to claim 15, wherein the molded article is molded. Prior to the biaxial stretch blow molding of the preform, the temperature of the blow molding die is adjusted to 90 to 70 ° C. or less to heat and melt the adhesive layer of the label. The method for producing an in-mold label biaxially stretched blow molded article according to claim 15, wherein the article is subjected to axial stretch molding.

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