JP4505875B2 - Synthetic resin molded products with labels formed only by printing - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a synthetic resin molded article, particularly a PET bottle, provided with a label formed only by printing.
[0002]
[Prior art]
Synthetic resin molded products are widely used in various fields represented by containers for beverages and toiletries because of their characteristics such as processability, durability, and lightness. Adhesive labels, glue labels, sleeve labels, Various decorations and decorations such as direct printing by a label such as a heat-sensitive label and an in-mold label, a screen printing method, an offset printing method and the like are given.
In particular, PET bottles are non-toxic, have superior gas barrier properties and moisture permeability than other synthetic resin molded products, and have a glassy appearance, especially for beverage containers and liquid seasonings. It is used as a container for cosmetics, a container for cosmetics, and a container for pharmaceuticals, and the surface of the container may be subjected to any of the above labels or screen printing for display or decoration of product description, product name, etc. Many.
[0003]
Also, in recent years, recycling of various manufactured products including synthetic resin molded products has been studied from the viewpoints of serious waste problems, prevention of global warming due to CO _z , resource saving, etc., for soft drinks, soy sauce, alcoholic beverages For synthetic resin moldings other than PET bottles for industrial use, methods such as oiling and coking are currently being studied.
However, all the above-described labels require various processes for manufacturing. For example, the adhesive label is a process of applying and drying an adhesive for holding the label on a substrate such as a plastic film, paper, or synthetic paper, a process of bonding with a release paper, a release film, an offset, a gravure, a screen, a letterpress For example, a process of displaying or decorating a product description, a product name, or the like by printing such as a process of punching into a target label shape is required. Furthermore, when using as a decoration or decoration to a synthetic resin molded product, the process affixed on a synthetic resin molded product is needed. Thus, in order to label a synthetic resin molded product, many various processes are required, resulting in high costs. Furthermore, since the pressure-sensitive adhesive label is generally supplied after being attached to a release paper or release film, the release paper or release film after the label attaching step becomes a problem in terms of waste and resource saving.
[0004]
In addition, for PET bottles for soft drinks, soy sauce, and alcoholic beverages, a law on the promotion of separate collection and re-commercialization related to containers and packaging was promulgated in 1995, and separate collection and re-commercialization began on April 1, 1997. The enforcement of has started. The collected PET bottles for soft drinks, soy sauce, and alcoholic beverages are recycled through a reprocessing process such as washing with hot water or a hot alkaline aqueous solution or specific gravity separation in a large-scale reprocessing facility. Recycling equipment is manually separated and removed for recycling.
In this way, PET bottles for soft drinks, soy sauce, and alcoholic beverages have been recycled from the viewpoint of environmental protection and resource saving in recent years, and various decorations such as labels applied to PET bottles are separated and removed. How to do is being studied.
[0005]
However, for labels such as adhesive labels, glue labels, heat-sensitive labels, and in-mold labels applied to the PET bottles, regeneration processing such as washing with hot water or hot alkaline aqueous solution or specific gravity separation in a large-scale regeneration processing facility. It is often difficult to peel off, separate and remove even after going through the process, and it is very expensive because it requires manual separation and removal, such as cutting the label part with a cutter or knife, even in small and medium-sized recycling facilities. turn into.
For direct printing by screen printing, for example, JP-A-8-34868 discloses a thermoplastic resin product printed with an ink composition soluble in an alkaline aqueous solution, and a thermoplastic resin printed with such an ink. A method is disclosed in which a printed product is desorbed with an aqueous alkaline solution.
However, when these printings are applied to the PET bottle, regeneration processing is possible in a large-scale regeneration processing factory having a cleaning facility using a hot alkaline aqueous solution, but it is difficult to remove the printing by a recycling company that does not have a cleaning facility. It becomes.
[0006]
[Problems to be solved by the invention]
It is desired to reduce the cost by producing and affixing labels applied to synthetic resin molded articles represented by soft drinks, soy sauce, liquor PET bottles and the like with as few steps as possible. Moreover, it is anxious to make the direct printing by the label and screen printing applied to a synthetic resin molded product correspond to a wide range of recycling systems.
[0007]
[Means for Solving the Problems]
Thus to the gist of the present invention when taken to improve the problems described above, the substrate is PET bottles, the surface of the 該被 printed material, the printing film is cured by ultraviolet rays or electron beams that have a peelable with Lee Nki plus nonionic surfactant ester or amide in the radiation-curable ink to form a label support layer in direct printing, further, the printing of the symbols and characters on the label support layer A label formed by printing only, characterized in that the laminated printed film formed by the above-mentioned label support layer has a holding power to the printed material and can be easily peeled by hand (hereinafter, It is in a synthetic resin molded product to which this label is applied.
[0008]
Label backing layer of this label, because it is formed by printing directly on the surface of the synthetic resin molded article, the label has a holding force to the synthetic resin molded article, moreover, the label support layer printing Since the film is formed of a releasable ink, the label can be easily peeled by hand.
[0009]
And since a label can be formed only by a simple printing process by using the synthetic resin molded product of this invention, a label can be given to a synthetic resin molded product at low cost. Further, the label can be applied to the synthetic resin molded product without generating industrial waste such as release paper or release film in the adhesive label.
Further, by using a synthetic resin molded article of the present invention, since the peeled by hand at the consumer stage this label applied to the synthetic resin molded product prior to recycling, it is possible to recover, in the processing facility It is possible to easily recycle without removing the decoration.
[0010]
Furthermore, the present label (hereinafter referred to as the present label 2) in which a label support layer is formed with an ink obtained by adding an ester-based or amide-based nonionic surfactant to an ink having a peelable print film. ) Can be peeled off by hand and also has a peelable function by treatment with hot water or hot alkaline aqueous solution, so it is possible to remove decorations in batches even in treatment equipment that performs hot water treatment or alkali treatment, and is compatible with a wide range of recycling systems. it can.
Especially for decorations applied to PET bottles for soft drinks, soy sauce and liquors, the label of the present invention can be easily peeled off by hand by forming the label in the present invention on the surface of the PET bottle. Labels can be easily removed by consumers and remanufacturers for efficient reproduction. By forming the label in the present invention on the surface of the PET bottle, there is no reduction in the product image and product value due to the peeling of the label in the product distribution process. On the other hand, after the contents are consumed, the product is consumed before the PET bottle is discarded. Can remove the label by hand and remove it. Further, by applying the present label 2 in the present invention to the surface of the PET bottle, even if the label of the present invention is recovered without being peeled off at the consumer stage, the recovery processing step in the recovery processing facility after recovery, or Even recyclers who do not have cleaning equipment can easily remove labels. Furthermore, the label can be removed and removed even in a washing process using hot water or a hot alkaline aqueous solution in a regeneration treatment facility.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of the present invention will be described. FIG. 1 is a cross-sectional view of an embodiment of the present invention, and FIG. 2 is a plan view showing an example of a printing pattern of a label support layer.
The substrate 1 is a synthetic resin molded product, particularly a PET bottle. A PET bottle is a container molded by hollow molding, biaxial stretch blow molding, injection molding or the like using a saturated polyester represented by polyethylene terephthalate as a raw material.
Many synthetic resin molded products such as polyester resin products, polyolefin resin products, vinyl chloride resin products, and polystyrene resin products can be used.
[0012]
Inks with a peelable print film are generally the same inks that are marketed under the names of masking ink, strippable ink, peelable resist ink, etc., and the print film is held in the desired synthetic resin molded product. It has a function capable of being physically removed while having power.
[0013]
These inks include radiation curable inks, evaporative drying inks, thermosetting inks, plastisol inks, etc., all of which can be used, but printing workability, printed film thickness, working environment, VOC Considering the problem and running cost, it is desirable to use radiation curable ink that cures with ultraviolet rays or electron beams. In particular, radiation curable screen printing ink mainly composed of urethane acrylate has a flexible printed cured film, and The label support layer 2 having the property of being easily peelable as a series of films can be formed because it has a property that is difficult to break.
[0014]
By adding an ester-based or amide-based nonionic surfactant to the ink for forming the label support layer 2, it is possible to increase the releasability with warm water in addition to being able to be peeled off by hand. When the printed film is immersed in water at room temperature by using an ink prepared by adjusting the nonionic surfactant in the range of 0.1 to 10 parts with respect to 100 parts of the ink having a peelable printed film. However, it does not peel in a short time, and can be peeled off within 5 minutes with water at 80 ° C. or higher or an alkaline aqueous solution at 80 ° C. or higher.
[0015]
Ester-based or amide-based nonionic surfactants include sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene sorbit fatty acid ester, sucrose fatty acid ester, fatty acid diethanolamide, fatty acid ester of polyethylene glycol, fatty acid ester of polypropylene glycol, Glycerin fatty acid ester, polyglycerin fatty acid ester, polyoxyethylene glycerin fatty acid ester, polyoxyethylene alkylamine fatty acid amide, monoalkylamine fatty acid amide, dialkylamine fatty acid amide, etc. can be used, but toxic It is desirable to use a small amount of highly biodegradable surfactant, and sorbitan fatty acid esters and sucrose fatty acid esters that are approved as food additives and cosmetic ingredients. It is preferable to use a nonionic surfactant such as ether-based.
[0016]
The label in the present invention is a laminated printed film 4 formed by a printing method. The laminated printed film 4 is composed of a plurality of prints that are printed on the label support layer 2 of the solid print portion directly attached on the surface of the synthetic resin molded product and the pattern or character 3 formed thereon. ing.
[0017]
Since the label support layer 2 in the above configuration needs to be a sufficiently thick film that is difficult to break, it is desirable to form the label support layer 2 using a screen printing method that increases the thickness of the printed film.
[0018]
The label support layer 2 formed on the surface of the synthetic resin molded product can be peeled by hand as long as it is 5 μm or more, but preferably the printed film thickness is printed once or overprinted twice or more. By adjusting to 15 μm to 200 μm, the present label can be easily peeled continuously without being cut halfway.
[0019]
The label support layer 2 formed by printing on the surface of the synthetic resin molded product is preferably printed with one solid so as to cover the entire decorative surface by the first screen printing in order to reduce the labor of peeling. If necessary, the shape may be divided into two or more solid portions by printing once or twice or more due to the shape or design problem of the synthetic resin molded product.
[0020]
By providing the projecting pattern 5 formed continuously at the end of the label support layer 2, the label can be peeled off from the portion, and the label can be easily and physically peeled off by hand.
[0021]
Further, by releasing the release agent 6 in advance on a part of the surface of the synthetic resin molded product corresponding to the printing end portion of the label support layer 2, that is, for example, a portion corresponding to the protruding pattern 5, the release of the label is performed. Since it is easier to manually start peeling from the agent-coated portion, the label can be easily and physically peeled by hand.
[0022]
As the release agent 6, a surfactant, a silicone compound, a fluorine compound, a low-volatility viscous liquid organic compound, or the like can be used. Application by brushing, screen printing, tampo printing, transfer with a rubber roller, spraying Application is performed by a known method such as spraying.
[0023]
The product description, product name, and design printed on the label support layer 2 are printed by known printing methods such as screen printing, offset printing, pad printing, in-jet printer printing, hot stamping, and transfer printing. However, it is desirable to use a radiation curable ink for screen printing.
[0024]
【Example】
UV curable screen printing ink containing 5 parts of sorbitan fatty acid ester in 100 parts of ink that has a function that the printed film mainly composed of urethane acrylate has a holding power against PET bottles and can be peeled by hand. It was adjusted.
Further, a 80-mesh (/ cm) polyester screen was used to produce a screen printing plate for forming a protruding pattern 5 as a peeling start portion as shown in FIG. 2 by printing.
[0025]
On the surface of the PET bottle body molded by the biaxial stretch molding method, the ink and the screen plate were used to perform screen printing, and then the UV accumulated light amount of 200 mj / mm was applied to the printed surface by a 120 W / cm metal halide ultraviolet lamp. A label-like printed film having an average thickness of 48 μm was obtained by irradiating ultraviolet rays of cm ² . The surface of the PET bottle corresponding to the peeling start part in the pattern of the printed film was previously coated with a surfactant by brushing before printing.
Furthermore, a screen made of a 130 mesh (/ cm) polyester screen is used on the label support layer 2 formed as described above by using an ultraviolet curable screen printing ink commercially available for general industrial use, and screen printing is performed. After the printing, the printed surface 4 was irradiated with ultraviolet rays with an accumulated ultraviolet light amount of 200 mj / cm ² by a 120 W / cm metal halide ultraviolet lamp to obtain a multilayer printed film 4.
[0026]
The laminated printed film 4 is not peeled at all even in a severe test in which a load is repeatedly applied to the body of the container, and even if the container is immersed in water at 20 ° C. for 10 minutes, the appearance changes such as peeling. Was not recognized, and it had a holding power enough to withstand practical use.
By scratching the protruding pattern 5 of the first label-like printed film in this laminated film with a fingernail and pinching the slightly peeled portion, a continuous film is formed and the entire laminated film is applied to the container surface. Even a part was peeled off without remaining, and was completely separated from the container body.
Further, when the container with the laminated printed film was immersed in hot water at 80 ° C., it became a film within 3 minutes after immersion, and the entire laminated film was peeled off without remaining even partially on the container surface. Completely separated from the torso.
[0027]
【The invention's effect】
By using the synthetic resin molded product of the present invention, especially for soft drinks, soy sauce, and alcoholic beverage PET bottles, there is no reduction in product image, product value, etc. due to label peeling in the product distribution process. After consumption, the label can be removed very easily at the consumer stage or at the recycling stage. Furthermore, a synthetic resin molded product can be provided easily and at low cost, and a labeling system that is friendly to the global environment from the manufacturing stage of the synthetic resin molded product to recycling can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a synthetic resin molded product provided with a label formed only by printing according to the present invention.
FIG. 2 is a plan view showing an example of a printing pattern of a label support layer subjected to printing according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Printed material 2 Label support layer 3 Design and character 4 Laminated printing film 5 Protruding pattern 6 Release agent

Claims (3)

The substrate (1) is a PET bottle, on the surface of the 該被 printed material (1), the printing film is nonionic ester type or amide type in the radiation curable ink which is cured by ultraviolet rays or electron beams that have a peelable label support layer (2) formed by direct printing using a Lee Nki plus sex surfactant, further comprising subjecting the printing of symbols and characters (3) on the label substrate layer (2) The laminated printed film (4) is formed only by printing, characterized in that the label support layer (2) has a holding force on the substrate (1) and can be easily peeled by hand. Synthetic resin molded product with an open label. Label support layer (2) is a synthetic resin molded article having been subjected to label formed by only claim 1 Symbol placement of printed formed by screen printing with a thickness of 15 to 200 m. Label support layer (2) of the composed successively to an end protruding pattern (5) is provided claims 1 or 2 Symbol synthetic resin molded article having been subjected to label formed by printing only the mounting.

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