JP5589400B2 - Packaging material and package - Google Patents

Description

  The present invention relates to a packaging material, and more particularly to a packaging material capable of clear laser printing without deterioration or discoloration of the substrate due to laser irradiation from the colored ink layer surface of the colored ink layer and the silver ink layer. is there.

In the present specification, “ratio”, “part”, “%” and the like indicating the composition are based on mass unless otherwise specified, and the “/” mark indicates that they are integrally laminated.
“PET” is an abbreviation, functional expression, common name, or industry term for “polyethylene terephthalate”, “LDPE” for “low density polyethylene”, “Al” for “aluminum”, and “PTR” for “cellophane”. .

(Background Technology) Conventionally, the surface of packaging materials used for packaging containers for pharmaceuticals, beverages, foods, etc., along with information common to products such as product name and product design, manufacturing place, date of production, expiration date, manufacturing The person in charge is listed. The former common information is printed on the packaging bag before the contents are sealed, but the latter is written by the nature when the contents are stored and sealed, and entered in a predetermined recording frame part on the outer surface of the bag. Is done. As this description method, printing is performed directly on the surface of the packaging material with ink, or a separately printed label is affixed. However, the mechanical printing method is not appropriate for a package with an irregular surface or a flexible package containing impact-sensitive contents, and the printed part may disappear during handling or transportation. There are problems such as detachment. As a countermeasure, a printing method for drawing and describing characters and symbols on the printing surface of the package by laser irradiation is performed. However, since the laser beam is irradiated from the base film side, the base film layer is whitened and the appearance is deteriorated, or one part of the layer structure is damaged, and the preservability of contents such as barrier properties In many cases, a plurality of layers such as a white layer, a black layer, and a metal layer are required to make the laser printing easy to read, and the cost is high. Moreover, since the difference in print density is small, there is a drawback that it is difficult to read. Furthermore, when cellophane is used as a base material, there is a disadvantage that the pitch (dimension in the running direction) becomes unstable when processing in a wound shape, although it does not whiten.
Packaging materials can be clearly laser-printed by laser irradiation, do not discolor due to whitening of the base material, have good dimensional stability, maintain functionality such as barrier properties, and have little change in appearance image. It has been demanded.

Japanese Patent Laid-Open No. 09-175013 JP 2009-67467-A

(Prior Art) Conventionally, as a display material having a printing portion that can be printed at high speed using a laser beam and does not disappear even if the printing contacts with acid, alkali, etc., the surface side is made of a color other than white. It is known to form a desired print by removing the first print layer by irradiating the first print layer and a display material provided with a white second print layer on the lower surface of the first print layer by laser light irradiation ( For example, see Patent Document 1.) However, it is composed of a layer other than white and a white layer, and there is a disadvantage that there is no reflected laser light from the lower part only by direct laser light irradiation, and printing efficiency is poor.
In addition, as a packaging material capable of laser marking, which has excellent substrate stability and excellent print discrimination, a light-colored ink coating layer, a silver ink coating layer, a plastic substrate layer, and a dark color ink from the outer layer to the inner layer Laser light is applied to the laminate on which the coating layer is laminated, the light-color ink coating layer and the silver ink coating layer disappear, and the dark-color ink coating layer is exposed to print information. What is provided is also known (see, for example, Patent Document 2). However, the light ink coating layer and the silver ink coating layer disappear, and the dark ink coating layer appears, that is, the silver ink coating layer disappears by irradiation with laser light. There is a problem that the laser output is required. Patent Document 2 is based on the applicant's application, and Patent Document 2 does not describe or suggest a technical idea of performing laser printing using laser light reflected from the silver ink layer.

  In order to solve the above-described problems, the present inventors have made extensive studies and have completed the present invention. Its purpose is packaging material that can be clearly laser-printed by laser irradiation, does not discolor due to whitening of the base material, has good dimensional stability, maintains functionality such as barrier properties, and has little change in appearance image. Is to provide.

In order to solve the above problems, a packaging material according to the first aspect of the present invention is a gas barrier in which a base material, a first polyolefin resin layer, a metal layer, and a second polyolefin resin layer are sequentially laminated. A laser-printing area in which the base material is a polyester resin, and a colored ink layer and a silver ink layer are laminated in this order on at least a part of the base material on the first polyolefin resin layer side. And when the laser beam is irradiated from the substrate side, the colored ink layer is made transparent by the laser beam transmitted through the substrate and reaching the colored ink layer and the laser beam reflected from the silver ink layer. The first polyolefin resin layer absorbs the laser beam transmitted through the base material, the colored ink layer and the silver ink layer to maintain the gas barrier property of the metal layer. Moreover, those base material so as not to discolor the laser irradiation, which was.
A packaging material according to a second aspect of the present invention is the packaging material according to the first aspect, wherein the laser beam is a carbon dioxide laser beam, and the gas barrier property after the laser beam irradiation of the packaging material is a gas barrier property before the laser beam irradiation. 90% or more is retained.
The package according to the invention of claim 3 is such that the pattern formed by laser printing is variable information using the packaging material according to any one of claims 1 and 2.

According to the first aspect of the present invention, clear laser printing can be performed by laser irradiation, the base material is not discolored such as whitening, dimensional stability is good, and functionality such as barrier properties is maintained, and an appearance image is obtained. This produces an effect with little change.
According to the second aspect of the present invention, the gas barrier property is not deteriorated even by the laser irradiation, and the contents can be stored with excellent effects.
According to the third aspect of the present invention, individual and unique variable information such as a production lot and a shelf life can be printed by laser printing, and there is an effect that it is possible to provide a package that can be consumed safely.

It is sectional drawing of the packaging material which shows one Example of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  (Packaging Material) As shown in FIG. 1, the packaging material 10 of the present invention comprises a base material 11 / first polyolefin resin layer 15 / metal layer 17 / second polyolefin resin layer 19. The colored ink layer 13 and the silver ink layer 14 are provided on at least a part of the surface of the substrate 11, and the substrate 11 / colored ink layer 13 / silver ink layer 14 / first polyolefin resin layer 15 / metal layer 17 / first. 2 It has a layer structure of a polyolefin resin layer 19.

  (Effect) According to this invention, there can exist the following effects. When irradiated with laser light, the laser light energy that has passed through the base material 11 and reached the colored ink layer 13 in the laser printing region causes the pigments and dyes in the ink to scatter and become transparent. The silver ink layer 14 can be observed, and the contrast enables the laser characters to be seen. In principle, printing can be performed without the silver ink layer 14, but without the silver ink layer 14, the laser light transmitted through the substrate 11 and the colored ink layer 13 passes through and is attenuated. Further, it may pass through the first polyolefin resin layer 15 to reach the metal layer 17 and may be reflected back by the metal layer 17, but it is very weak energy and no longer contributes to printing.

  Therefore, in the present invention, by providing the colored ink layer 13 and the silver ink layer 14 in this order, the reflected laser light energy from the silver ink layer 14 is used, so that printing can be performed with a laser beam with less energy. That is, the colored ink layer can be made transparent and laser printing can be performed by the sum of the laser light transmitted through the substrate 11 and reaching the colored ink layer 13 and the laser light reflected and returned from the silver ink layer. .

  And the metal layer 17 is protected by the 1st polyolefin resin layer 15 absorbing the laser beam which permeate | transmitted the base material 11 / colored ink layer 13 / silver-colored ink layer 14. FIG. That is, the metal layer 17 can be prevented from being deteriorated by the laser beam and the gas barrier property can be maintained.

  Furthermore, ordinary cellophane, which is a general base material, is easily whitened when irradiated with a carbon dioxide laser, but by using a PET film as the base material 11, it is difficult to whiten and has an excellent appearance. Further, the layer structure of the substrate 11 / colored ink layer 13 / silver ink layer 14 / first polyolefin resin layer 15 / metal layer 17 / second polyolefin resin layer 19 is used, so that the laser printing portion is the underlying silver color. Since the ink layer 14 can be observed and the metal layer 17 can be observed in portions other than the laser printing region, there is a feature that there is uniformity, very little change in appearance, and there is no sense of incongruity.

  (Substrate) As the substrate 11, a polyester-based resin is used, and examples thereof include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), and may be a copolymer. The polyester-based resin may be either stretched or unstretched, but a biaxially stretched film is preferred because it preferably has mechanical strength and dimensional stability.

  In addition, the base material 11 has processability, heat resistance, weather resistance, mechanical properties, dimensional stability, antioxidant properties, slipperiness, releasability, flame retardancy, antifungal properties, electrical properties, strength, For the purpose of improving and modifying others, for example, colorants such as lubricants, crosslinking agents, antioxidants, UV absorbers, light stabilizers, fillers, antistatic agents, lubricants, antiblocking agents, dyes, pigments, etc. Nard may be added. Although it does not receive a restriction | limiting in particular as thickness of the base material 11, When the suitability and workability as a packaging material are considered, it is preferable that it is 4.5-250 micrometers, More preferably, it is 12-100 micrometers.

  Conventionally, ordinary cellophane, which is a general base material, is easily whitened when irradiated with a carbon dioxide laser, but by using a PET film as the base material 11, it is difficult to whiten and has an excellent appearance.

  (Colored ink layer) The colored ink layer 13 comprises at least colored pigments and / or dyes and a binder (also referred to as a vehicle), and if necessary, a plasticizer, a stabilizer, an antioxidant, a light stabilizer, an ultraviolet ray One or more additives such as an absorbent, a curing agent, a crosslinking agent, a lubricant, an antistatic agent, a filler, and the like may be optionally added. The colored pigment and / or dye is not particularly limited, and one or more may be used.

  As the binder, known ones such as linseed oil, drill oil, soybean oil, hydrocarbon oil, rosin, rosin ester, rosin modified resin, shellac, alkyd resin, phenolic resin, maleic acid resin, natural resin, carbonized Hydrogen resin, polyvinyl chloride resin, polyacetic acid resin, polystyrene resin, polyvinyl butyral resin, acrylic or methacrylic resin, polyamide resin, polyester resin, polyurethane resin, epoxy resin, urea resin, melamine resin, One or more of aminoalkyd resins, nitrified cotton, nitrocellulose, ethylcellulose, chlorinated rubber, cyclized rubber, etc. can be used in combination.

  The above binder, colored pigment and / or dye, and additives as necessary are added, and dispersed and kneaded with a solvent, a diluent or the like to obtain an ink composition. The colored ink layer 13 may be formed by printing on the substrate 11 using the ink composition by a conventional printing method such as gravure printing, letterpress printing, screen printing, flexographic printing, or the like. Further, the colored ink layer 13 may be formed at a desired location where laser printing is to be performed, and does not need to be formed on the entire surface, and may be shared with other patterns.

  By irradiating the colored ink layer 13 with laser light from the base material 11 side of the packaging material 10, the color can be changed by the thermal energy of the laser light and laser printing can be performed. For this reason, the colored ink layer 13 to be used may be blended with a laser light absorber, or the binder to be used may be specified to improve the laser light absorption ability. However, a laser-printable packaging material can be provided, and commercially available colored inks such as red, blue, green, and purple can be used.

  The thickness of the colored ink layer 13 is not particularly limited, and is about 1 to 20 μm, more preferably 2 to 10 μm. The colored ink layer 13 may be formed by one-time printing (one-time printing) or a plurality of times printing (multi-color printing), but the number of times of printing is preferably 1 to 3, and the cost is more than 4 times. It is disadvantageous in terms.

(Silver ink layer) As the silver ink layer 14, a metallic printing ink such as silver or gold using a metal pigment such as aluminum paste or aluminum powder is used.
The aluminum paste includes a leafing type and a non-leafing type, and any of them may be used, and ink using a powder obtained by pulverizing a deposited aluminum thin film may be used.
The silver ink layer 14 may be formed by a known printing method such as a gravure printing method, screen printing, flexographic printing, etc., and may be provided on at least the colored ink layer 13 surface. Of course, it may be simultaneously formed on other printed patterns. All patterns such as patterns and photos can be used.

  (First polyolefin-based resin) The first polyolefin-based resin layer 15 may be made of a polyolefin-based resin having various heat-fusible properties that can be melted by heat and fused to each other. Specifically, LDPE low density polyethylene, medium density polyethylene, high density polyethylene, linear (linear) low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ionomer resin, ethylene-acrylic acid copolymer, Resins such as ethylene-ethyl acrylate copolymer, ethylene-methacrylic acid copolymer, and their cross-linked metal, ethylene-α / olefin copolymer polymerized using metallocene catalyst, polypropylene, ethylene-methacrylic acid Polyolefin resins such as methyl copolymer, ethylene-propylene copolymer, methylpentene polymer, polybutene polymer, polyethylene or polypropylene are unsaturated such as acrylic acid, methacrylic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid Modified with carboxylic acid Modified polyolefin resins, polyvinyl acetate resins, poly (meth) acrylic resins, such as one or more films or sheets or coating film made of a resin such as polyvinyl chloride-based resin can be used. The thickness of the first polyolefin resin layer 15 is not particularly limited and can be determined according to the purpose, and is generally in the range of 15 to 100 μm.

  (Metal layer) As the metal layer 17, for example, an aluminum foil, a copper foil, a tin foil, various alloy foils, and the like can be used. In general, an aluminum foil is used. The film thickness of the metal foil is about 6 to 50 μm, preferably about 7 μm to 20 μm.

  (Second Polyolefin Resin) The second polyolefin resin layer 19 can use the same resin as the first polyolefin resin layer 15. The second polyolefin resin layer 19 and the first polyolefin resin layer 15 may be the same or different. The thickness of the second polyolefin resin layer 19 is not particularly limited and can be determined according to the purpose, and is generally in the range of 15 to 200 μm.

  (Other Layers) Other layers such as an intermediate substrate and a design printing layer may be provided on the interlayer and / or the substrate surface of the packaging material 10 as long as laser printing is not affected. As such other layers, each other layer may be laminated by a dry laminate lamination method or a melt extrusion method, or may be formed by a known printing method.

  (Design Print Layer) The packaging material 10 may have a design print layer on the inside or outside of the substrate 11 other than the laser printing region. The design printing layer can be formed by a conventionally known printing method such as gravure printing, screen printing, or flexographic printing. The design printing layer may be simultaneously performed by the multicolor printing method when the colored ink layer 13 and / or the silver ink layer 14 is printed. Of course, the design pattern is placed outside the laser printing area of the colored ink layer 13 and the silver ink layer 14. You may print using the same plate.

  (Manufacturing method) The packaging material 10 has a layer structure of base material 11 / colored ink layer 13 / silver ink layer 14 / first polyolefin resin layer 15 / metal layer 17 / second polyolefin resin layer 19. First, a colored ink layer 13 and a silver ink layer 14 are provided on the surface of the substrate 11 by a known printing method such as a known gravure printing method, screen printing, flexographic printing, etc., and the first polyolefin resin is applied to the silver ink layer 14. The layer 15 is melt-extruded, and the metal layer 17 is laminated, so that it is polysanded by a so-called extrusion coating method. Further, if necessary, an anchor coat may be applied to the surface of the metal layer 17 and dried, and the second polyolefin resin layer 19 may be melt extruded and laminated by a so-called extrusion coating method.

  (Laser printing) The laser printing method is based on the substrate 11 surface of the substrate 11 / colored ink layer 13 / silver ink layer 14 / first polyolefin resin layer 15 / metal layer 17 / second polyolefin resin layer 19 The laser light energy that has passed through the base material 11 and reached the colored ink layer 13 in the laser printing area is irradiated with laser light, and the pigments and dyes in the ink are dispersed by evaporation or the like to become transparent. The ink layer 14 can be observed, and the laser characters can be seen by the contrast. However, some of the pigments and dyes in the colored ink layer 13 serving as the printing portion may fly like an indigo pigment, for example. Therefore, in the present invention, by providing the colored ink layer 13 and the silver ink layer 14 in this order, the reflected laser light energy from the silver ink layer 14 is used, so that printing can be performed with a laser beam with less energy. That is, the colored ink layer can be made transparent and laser printing can be performed by the sum of the laser light transmitted through the substrate 11 and reaching the colored ink layer 13 and the laser light reflected and returned from the silver ink layer. . Further, the colored ink layer 13 may be carbonized by laser light energy.

  Further, since the laser light is irradiated so as to pass through the surface of the base material 11, the base material 11 is affected by the laser light, and the mechanical strength of the base material 11 is reduced, discolored, altered or deformed. The storage stability of the contents may be reduced. Therefore, the base material 11 is made of a polyester resin that can suppress the occurrence of melting, breakage, pinholes, and wrinkles, has mechanical strength, and is excellent in heat resistance.

  The laser beam used for laser printing is not particularly limited as long as it can be used for laser printing. For example, a YV04 laser, a carbon dioxide gas laser, a YAG laser, a semiconductor laser, and the like can be used. It is a gas laser (wavelength = 10.6 μm). Irradiation output, printing speed, and the like may be appropriately selected according to the type and thickness of the base material 11 of the packaging material 10.

  (Packaging body) The packaging body of the present invention is laminated so that the polyolefin resin layer 19 of the packaging material 10 is opposed to each other, and thereafter, the three ends of the outer periphery are heat-sealed to form a heat-sealing portion. A three-side sealed packaging bag can be manufactured by forming and forming an opening in the upper part. In addition, as a shape of the packaging bag of the present invention, a packaging bag having various forms suitable for contents such as a pillow packaging form, a gusset packaging form, a standing (self-supporting) pouch packaging form, and the like can be manufactured. In addition, as a method of heat sealing | fusion, it can carry out by well-known methods, such as a bar seal, a rotary roll seal, a belt seal, an impulse seal, a high frequency seal, an ultrasonic seal, for example. The package may be an easy-opening means such as a notch that facilitates the opening operation at the top. As the notch, a notch such as a letter shape or a V shape is usually used, but the shape is not particularly limited, and any shape having an acute angle portion in the cutting direction can be used.

  The packaging material 10 has at least a part thereof a laser printing region composed of the colored ink layer 13 and the silver ink layer 14, and there is no limitation on the position where the laser printing region is formed in the packaging body, and the front surface and / or the back surface of the packaging body. It is only necessary that a laser printing region is formed in one part of the above.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further in detail, it is not limited to this. In addition, except a solvent, each composition of each layer is a mass part of solid content conversion.

(Example 1) A biaxially stretched PET film having a thickness of 12 μm was used as the base material 11, and green ink (manufactured by DIC Graphics, urethane-based “CLIS” green ink) and silver ink (manufactured by DIC Graphics, Using a urethane-based “CLIOS” silver ink, a green ink layer (colored ink layer 13) and a silver ink layer (silver ink layer 14) were formed by gravure printing in a size of 2 cm × 4 cm. .
A polyethyleneimine anchor coating agent is applied to the surface of the silver ink layer 14, dried, LDPE 15 μm to be the first polyolefin resin layer 15 is melt-extruded, and the thickness to be the metal layer 17 is 9 μm by the so-called polysand method. Laminated with aluminum foil.
A polyurethane-based anchor coating agent is applied to the aluminum foil surface and dried, and LDPE 40 μm to be the second polyolefin-based resin layer 19 is melt-extruded, and PET 12 μm / green + silver ink layer / LDPE 15 μm / Al foil 9 μm / LDPE 40 μm The packaging material 10 of Example 1 was obtained.

  (Example 2) Implementation was performed except that purple ink and silver ink were used instead of green ink and silver ink to form a purple ink layer (colored ink layer 13) and a silver ink layer (silver ink layer 14). In the same manner as in Example 1, the packaging material 10 of Example 2 consisting of PET 12 μm / purple + silver ink layer / LDPE 15 μm / Al foil 9 μm / LDPE 40 μm was obtained.

  (Comparative Example 1) Comparative Example 1 comprising PT20 μm / green + silver ink layer / LDPE 15 μm / Al foil 9 μm / LDPE 40 μm in the same manner as in Example 1 except that a cellophane film having a thickness of 20 μm was used as the substrate 11. A packaging material 10 was obtained.

  (Comparative example 2) It consists of PET12micrometer / green ink layer / LDPE15micrometer / Al foil 9micrometer / LDPE40micrometer like Example 1 except not forming silver ink but forming only a green ink layer (colored ink layer 13). A packaging material 10 of Comparative Example 2 was obtained.

  (Evaluation method) Evaluation was made based on printability by laser printing, damage to the substrate, and gas barrier properties of the packaging material.

(Measurement method) The printability is irradiated output from the surface of the base material 11 of the packaging material 10 of Examples and Comparative Examples using a carbon dioxide laser marker ML-Z9520 (output 80 W, wavelength 10.6 μm) manufactured by Keyence Corporation. Irradiation was performed at 70 to 100% irradiation speed of 1000 to 2000 mm / sec, and the number “12345678910” was printed.
The printing was expressed as “◯” with the printing state and clearly visible one as acceptable.
The damage to the base material was expressed by “◯” with the result that the surface of the base material 11 of the packaging material 10 of the examples and comparative examples after laser irradiation was visually observed and there was no significant scratch or unevenness.
The gas barrier property of the packaging material is the oxygen permeability of the packaging material 10 of the example and comparative example according to JIS-K-7126, under the conditions of a temperature of 23 ° C. and a humidity of 90% RH, manufactured by Mocon, USA Measured using a measuring instrument [model name, OXTRAN 2/20], the gas barrier property after irradiation with laser light is maintained at 90% or more of the gas barrier property before laser light irradiation. Passed and indicated by “○”. The results are shown in Table 1.

  (Evaluation Results) In Comparative Example 1, the substrate deteriorated due to laser irradiation, the surface was uneven, and the surface was whitish. In Comparative Example 2, the substrate was not deteriorated and the gas barrier property was good, but the laser printing was blurred and not clear. In Examples 1 and 2, all evaluations were good.

  (Industrial Applicability) The present invention can be used for packaging materials used for packaging containers for pharmaceuticals, beverages and foods. However, it is particularly limited if the laser irradiation enables clear laser printing, the substrate does not whiten, the dimensional stability is good, the functionality such as barrier properties is maintained, and the appearance image has little change. Is not to be done.

10: Packaging material 11: Base material 13: Colored ink layer 14: Silver ink layer 15: First polyolefin resin 17: Metal layer 19: Second polyolefin resin

Claims (3)

A gas barrier packaging material in which a base material, a first polyolefin resin layer, a metal layer, and a second polyolefin resin layer are sequentially laminated,
The substrate is composed of a biaxially stretched polyester resin film ,
At least parts of the colored ink layer and the silver ink layer of a first polyolefin-based resin layer side of the substrate has a laser-printed regions are laminated in this order,
The laser light when irradiated from the substrate side, the laser beam reflected from the laser beam and the silver ink layer reaches to a colored ink layer passes through the substrate, the colored ink layer is, any and transparent pattern the possible laser printing,
And the 1st polyolefin resin layer absorbs the laser beam which permeate | transmitted the base material, the colored ink layer, and the silver ink layer, and maintains the gas barrier property of a metal layer,
And also packaging material substrate, characterized in that it does not discolor by the laser irradiation. The laser beam is a carbon dioxide gas laser beam, and the gas barrier property after irradiating the laser beam of the packaging material maintains 90% or more of the gas barrier property before the laser beam irradiation. The packaging material according to 1. A packaging body , wherein the pattern formed by laser printing using the packaging material according to claim 1 is variable information.

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