JP2019055792A - Selection method of packaging material, packaging material and retort container - Google Patents

Abstract

To provide a selection method of a packaging material which can achieve beautiful appearance by metallic luster without using a metal layer, and which can suppress change in the appearance in a circulation process.SOLUTION: In a selection method of a packaging material including a constitution in which at least a plastic film, a glossy print layer and a sealant layer are laminated from an outer layer side in this order, in the case where the print layer includes a photoluminescent pigment, an angle which shows reflection intensity 1/2 of regular reflection intensity of the reflection light of the packaging material satisfies a specific condition.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a packaging material sorting method, a packaging material, and a retort container.

  The packaging material may be decorated with high-brightness metallic luster from the viewpoint of producing a high-quality feeling and luxury of the packaged object and generating an aesthetic appearance. As such a decoration means, for example, a metal layer such as a metal vapor deposition film or a metal foil is generally formed.

However, the packaging material using a metal layer has a problem that the cost increases. In addition, the metal vapor deposition film in the metal layer cannot be produced in-line with other layers constituting the packaging material, so there is a problem that the production efficiency is poor, and the metal foil is difficult to handle in the metal layer. There is a problem.
Furthermore, when a packaging material using a metal layer is heated in a microwave oven, microwaves in the microwave oven may be reflected from the surface of the metal layer, resulting in sparks, resulting in a microwave oven failure or accident. There is also a problem that the contents in the packaging container cannot be heated sufficiently.

  For this reason, for example, Patent Document 1 proposes a packaging material in which a gloss layer is formed with an ink containing a high-intensity aluminum paste having a predetermined concentration instead of a metal layer.

JP 2017-81589 A

  However, although the packaging material like patent document 1 which gave the metallic luster feeling without using a metal layer had few generation | occurrence | production cases, the malfunction which an external appearance changed in the process of distribution of a packaging material was pointed out. .

The present invention has been made to solve the above technical problem, and can provide a aesthetic appearance due to metallic luster without using a metal layer, and can suppress a change in appearance during distribution. An object is to provide a method for sorting materials.
In addition, the present invention provides a packaging material that can produce an aesthetic appearance due to metallic luster without using a metal layer, and that suppresses a change in appearance during the distribution process, and a packaging container using the packaging material. With the goal.

  As a result of earnestly examining the cause of the change in the appearance of the packaging material in the distribution process, the present inventors have increased the strength of the retort treatment more specifically than usual in the retort treatment for pressure heat sterilization (specifically, It was found that the appearance of the packaging material changes during retort processing in a high temperature region of 130 ° C. or higher. The inventors have further studied and have completed the present invention.

That is, the present invention provides the following [1] to [3].
[1] A packaging material sorting method having a configuration in which at least a plastic film, a printing layer, and a sealant layer are laminated in this order from the outer layer side, and a glossy printing layer containing a glitter pigment as the printing layer In the case of having d ₁ , the angle indicating the intensity of the reflected light in the regular reflection direction of the packaging material measured under the following measurement condition 1 is d ₁ , and the positive of the packaging material measured under the following measurement condition 2 the angle indicating the half of the intensity of the intensity of the reflected light in the direction of reflection upon the d _2, and pass line satisfies the following formula (1), screening method of packaging.
| (D ₁ −d ₂ ) / d ₁ | × 100 ≦ 8.0% (1)
<Measurement condition 1>
A black plate is bonded to the surface of the packaging material on the sealant layer side through a transparent adhesive layer, and sample A in which the packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined 45 degrees from the normal direction of the sample A is incident on the surface of the sample A on the packaging material side, and the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the reference angle is the center. In the range of ± 15.0 degrees, the intensity of reflected light is measured every 0.1 degrees.
<Measurement condition 2>
A retort-treated packaging material obtained by retorting the packaging material with a batch type hot water shower type retort apparatus at 135 ° C. for 30 minutes is obtained. A black plate is bonded to the surface of the retort-processed packaging material on the sealant layer side through a transparent adhesive layer, and sample B in which the retort-processed packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined by 45 degrees from the normal direction of the sample B is incident on the surface of the sample B on the retort-treated packaging material side, and the regular reflection direction of incident light is set to 0 degree as a reference angle, and the reference angle is In the range of ± 15.0 degrees as the center, the intensity of the reflected light is measured every 0.1 degrees.

[2] A packaging material having a configuration in which at least a plastic film, a printing layer, and a sealant layer are laminated in this order from the outer layer side, and having a glossy printing layer containing a bright pigment as the printing layer, the angle indicating the half of the intensity of the reflection intensity of the specular reflection direction of the of the packaging material were measured under the measurement conditions 1 d _1, of the wrapping material was measured by the above measurement conditions 2 positive reflection direction of the reflected light A packaging material satisfying the following formula (1) when an angle indicating a strength of ½ of the strength is d ₂ .
| (D ₁ −d ₂ ) / d ₁ | × 100 ≦ 8.0% (1)
[3] A retort container in which at least a part is formed of the packaging material described in [2] above.

  According to the present invention, it is possible to provide a method for selecting a packaging material that can generate an aesthetic appearance due to metallic luster without using a metal layer and can suppress a change in appearance during distribution. In addition, according to the present invention, a packaging material that can generate an aesthetic appearance due to metallic luster without using a metal layer, and that suppresses a change in appearance during distribution, and a packaging container using the packaging material Can be provided.

It is a schematic sectional drawing which shows an example of the laminated structure of the packaging material of this invention. It is a schematic sectional drawing which shows an example of the laminated structure of the packaging material of this invention. It is a schematic sectional drawing which shows an example of the laminated structure of the packaging material of this invention. It is a schematic sectional drawing which shows an example of the laminated structure of the packaging material of this invention. It is sectional drawing which shows an example of the pouch for microwave ovens among the packaging containers of this invention. It is a top view which shows an example of the container with a lid | cover among the packaging containers of this invention. It is IV-IV sectional drawing of FIG. It is a figure explaining the measuring method of the intensity | strength of the reflected light of a packaging material. It is an intensity distribution map of the reflected light of the packaging material of Example 1. 6 is an intensity distribution diagram of reflected light of the packaging material of Comparative Example 1. FIG. It is a schematic sectional drawing which shows the other example of the laminated structure of the packaging material of this invention. It is a schematic plan view which shows the other example of the pouch for microwave ovens among the packaging containers of this invention. It is XI-XI sectional drawing of FIG.

  Hereinafter, the packaging material of the present invention, and the packaging container and lid using the packaging material will be described in detail. In addition, the notation of the numerical range of “AA to BB” in the present specification means “AA or more and BB or less”. Hereinafter, the “intensity of reflected light” may be referred to as “reflection intensity”.

[Method for sorting packaging materials]
The packaging material sorting method of the present invention is a packaging material sorting method having a configuration in which at least a plastic film, a printing layer, and a sealant layer are laminated in this order from the outer layer side, and the glittering property as the printing layer In the case of having a glossy printing layer containing a pigment, an angle indicating a half of the intensity of reflected light in the regular reflection direction of the packaging material measured under the following measurement condition 1 is d ₁ , and the measurement condition 2 is the angle indicating the half of the intensity of the reflection intensity of the measured specular reflection direction of the packaging material upon a d _2, in which the pass line satisfies the following formula (1).
| (D ₁ −d ₂ ) / d ₁ | × 100 ≦ 8.0% (1)

<Measurement condition 1>
A black plate is bonded to the surface of the packaging material on the sealant layer side through a transparent adhesive layer, and sample A in which the packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined 45 degrees from the normal direction of the sample A is incident on the surface of the sample A on the packaging material side, and the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the reference angle is the center. In the range of ± 15.0 degrees, the intensity of reflected light is measured every 0.1 degrees.
<Measurement condition 2>
A retort-treated packaging material obtained by retorting the packaging material with a batch type hot water shower type retort apparatus at 135 ° C. for 30 minutes is obtained. A black plate is bonded to the surface of the retort-processed packaging material on the sealant layer side through a transparent adhesive layer, and sample B in which the retort-processed packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined by 45 degrees from the normal direction of the sample B is incident on the surface of the sample B on the retort-treated packaging material side, and the regular reflection direction of incident light is set to 0 degree as a reference angle, and the reference angle is In the range of ± 15.0 degrees as the center, the intensity of the reflected light is measured every 0.1 degrees.

When the packaging material sorting method of the present invention has a glossy printing layer containing a bright pigment as the printing layer, the reflection of ½ of the reflection intensity in the regular reflection direction of the packaging material measured under the above measurement condition 1 When the angle indicating the intensity is d ₁ and the angle indicating the reflection intensity ½ of the reflection intensity in the regular reflection direction of the packaging material measured under the measurement condition 2 is d ₂ , the above formula (1) is satisfied. The packaging material is recognized as an acceptable line and selected.
Hereinafter, each measurement condition and Formula (1) are demonstrated.

<< Measurement conditions >>
FIG. 8 is a diagram for explaining a method of measuring the reflection intensity of the packaging material.
In order to measure the reflection strength of the packaging material, first, a sample 100 in which the black plate 50 is bonded to the surface of the packaging material 1 on the sealant layer 4 side through the transparent adhesive layer 40 is prepared. Next, visible light inclined by 45 degrees from the normal direction of the sample 100 is incident on the surface of the sample 100 on the packaging material 1 side. The solid line arrow in FIG. 8 indicates the incident light. Then, the intensity of the reflected light is measured every 0.1 degrees within a range of ± 15.0 degrees centered on the reference angle, with the regular reflection direction of incident light (the direction of the dashed arrow in FIG. 8) as the reference angle. To do. The plus direction means a direction away from incident light, and the minus direction means a direction approaching incident light.

  In the measurement condition 1, as the packaging material constituting the sample A, a packaging material that is not subjected to retort processing or high retort processing is used. In the measurement condition 2, as a packaging material constituting the sample B, a packaging material subjected to high retort processing is used. In addition, the packaging material used for the sample A and the sample B may be cut out from the packaging container. For example, a pouch may be produced using a packaging material, and the packaging material may be cut out from a high retort treatment of the pouch and used as a packaging material constituting sample B.

As the refractive index of the transparent adhesive layer 40 of the sample 100, a refractive index difference between the refractive index of the adherend 10 and the black plate 50 within 0.05 can be used, and preferably the refractive index difference is 0.00. 00. In this specification, the refractive index means a refractive index having a wavelength of 589 nm.
There is no restriction | limiting in particular about the apparatus which measures reflection intensity, A general purpose goniophotometer (goniophotometer) can be used. In the present invention, as a goniophotometer, a product number GP-200 manufactured by Murakami Color Research Laboratory Co., Ltd. (within an inclination angle within the luminous flux of 0.5 degrees or less) is used. The scale was “3”.

  The high retort process of the measurement condition 2 is a batch type hot water shower type retort apparatus, and performs the process at a hot water temperature of 135 ° C. for 30 minutes. Further conditions for the high retort treatment are preferably according to the conditions of the examples.

<< Formula (1) >>
The light reflected by the packaging material having the glossy printed layer containing the glitter pigment has a strong intensity in the specular reflection direction and expresses a metallic luster. Further, in normal attention, a human does not recognize a difference in intensity (brightness) in a range from the maximum intensity to a half of the maximum intensity. Therefore, it can be said that the range from the maximum intensity to a half of the maximum intensity is an important angle range for humans to feel a metallic luster. For this reason, it can be said that Formula (1) has shown the change rate of the angle range important for a human to feel a metallic luster feeling before and after a high retort process.

When “| (d ₁ −d ₂ ) / d ₁ | × 100” in Expression (1) exceeds 8.0%, the range of angles at which a person feels metallic luster after high retort processing is significantly widened. , Which means it will be much narrower.
Therefore, the packaging material which does not satisfy the formula (1) is changed to a design not intended by the manufacturer by being subjected to the high retort process. Moreover, even if the packaging material which does not satisfy | fill Formula (1) has the same metallic luster (the same external appearance) at the time of manufacture, it is the thing of the high retort process in the distribution process, and the thing which is not a high retort process Since the metallic luster is different, there may be a problem in product management, or when both are displayed side by side, the consumer may feel uncomfortable.
For this reason, it is possible to suppress the change in the metallic luster of the packaging material (change in appearance) during the distribution process by selecting a packaging material that satisfies the formula (1) as an acceptable line, and the design properties It is possible to stably supply a packaging material with a stable level.

Further, when metal scales are used as the luster pigment, the fact that the formula (1) is not satisfied indicates that the arrangement of the metal scales in the glossy printed layer may vary due to the high retort treatment. For example, when the absolute value of the formula (1) is removed and “((d ₁ −d ₂ ) / d ₁ ) × 100” is smaller than −8.0%, the arrangement of the metal scales is disturbed by the high retort treatment, The possibility that the space | interval of metal scales will become narrow is shown. And when the space | interval of metal scales becomes narrow, when it heats with a microwave oven, a spark may generate | occur | produce or a local overheating may arise and a hole may generate | occur | produce.
Therefore, by selecting a packaging material that satisfies the formula (1) as a pass line and selecting a packaging material that satisfies this, when a microwave oven is heated after a high retort treatment, sparks are generated or holes due to local overheating are generated. Occurrence can be suppressed, and a packaging material excellent in safety can be stably supplied.
That is, the packaging material sorting method of the present invention is also useful as a microwave packaging material sorting method.

“| (D ₁ −d ₂ ) / d ₁ | × 100” in the formula (1) is preferably 6.0% or less, and more preferably 4.0% or less.

FIG. 9 is a reflection intensity distribution diagram of the packaging material of Example 1, where the solid line indicates the reflection intensity before the high retort treatment and the dotted line indicates the reflection intensity after the high retort treatment. FIG. 10 is a reflection intensity distribution diagram of the packaging material of Comparative Example 1, in which the solid line indicates the reflection intensity before the high retort treatment, and the dotted line indicates the reflection intensity after the high retort treatment. However, in FIG. 9 and FIG. 10, the reflection intensity at each angle is normalized by setting the reflection intensity at the reference angle to 100.
9 and 10, the packaging material of Comparative Example 1 has a reflection intensity changed before and after the high retort treatment, whereas the packaging material of Example 1 is reflected before and after the high retort treatment. It can be confirmed that the strength hardly changes. The value of | (d ₁ −d ₂ ) / d ₁ | × 100 ”is 3.4% in Example 1 and 12.5% in Comparative Example 1.

Screening method for packaging material of the present invention is preferably applied to a packaging material d ₁ is excellent 2.0 degrees or less metallic luster. This is because, in such a packaging material that exhibits a high level of metallic luster, the stability of the design is regarded as important. d ₁ is more preferably 1.8 degrees or less, and still more preferably 1.7 degrees or less.
Note that when d ₁ is too small, the reflected light feel dazzling. Therefore, it is preferable that _{d 1} is not less than 1.0 degrees, more preferably not less than 1.2 degrees.

In the present specification, d ₁ and d ₂ are “α1”, which is an angle in the positive direction that first reaches an intensity of ½ or less of the intensity of the reflected light at the reference angle, and the intensity of the reflected light at the reference angle. The angle calculated by the expression “(α1 + | α2 |) / 2” when the angle in the minus direction that first reaches an intensity of ½ or less is “α2”.

The packaging material selection method of the present invention is the packaging material measured under the above measurement condition 2 with an angle d 1/2 indicating the intensity of the reflected light in the regular reflection direction of the packaging material measured under the above measurement condition 1 and d ₃ . the angle indicating the intensity of 1/20 of the intensity of the reflected light of the positive reflection direction upon the d ₄ of, it is preferable to pass line satisfies the following formula (2).
| (D ₃ −d ₄ ) / d ₃ | × 100 ≦ 15.0% (2)

  When a human observes a visual object from the regular reflection direction, it can detect brightness up to 1/20 of the reflection intensity at the reference angle. Therefore, the effect of the present invention can be further enhanced by using an acceptable line that satisfies the above formula (2).

“| (D ₃ −d ₄ ) / d ₃ | × 100” in the formula (2) is preferably 12.0% or less, more preferably 10.0% or less, and 8.0%. More preferably, it is as follows.

In this specification, d ₃ and d ₄ are “η1” which is an angle in the positive direction that first reaches an intensity of 1/20 or less of the intensity of the reflected light at the reference angle, and the intensity of the reflected light at the reference angle. The angle calculated by the expression “(η1 + | η2 |) / 2” when the angle in the minus direction that first reaches an intensity of 1/20 or less is “η2”.

Examples of the glitter pigment for the glossy printed layer include metal scales and pearl pigments.
The metal scale and the pearl pigment will be described later in the embodiment of the packaging material of the present invention. The plastic film, printing layer and sealant layer constituting the packaging material will also be described in the embodiment of the packaging material of the present invention described later.

[Packaging materials]
The packaging material of the present invention is a packaging material having a configuration in which at least a plastic film, a printing layer, and a sealant layer are laminated in this order from the outer layer side, and a glossy printing layer containing a glitter pigment as the printing layer An angle indicating a half of the reflection intensity in the regular reflection direction of the packaging material measured under measurement condition ₁ below, d ₁ , and the regular reflection direction of the packaging material measured in measurement condition 2 below the angle indicating the intensity of 1/2 of the intensity of reflected light upon a d _2, satisfies the following formula (1).
| 1- (d ₂ / d ₁ ) | × 100 ≦ 8.0% (1)

<Measurement condition 1>
A black plate is bonded to the surface of the packaging material on the sealant layer side through a transparent adhesive layer, and sample A in which the packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined 45 degrees from the normal direction of the sample A is incident on the surface of the sample A on the packaging material side, and the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the reference angle is the center. In the range of ± 15.0 degrees, the intensity of reflected light is measured every 0.1 degrees.
<Measurement condition 2>
A retort-treated packaging material obtained by retorting the packaging material with a batch type hot water shower type retort apparatus at 135 ° C. for 30 minutes is obtained. A black plate is bonded to the surface of the retort-processed packaging material on the sealant layer side through a transparent adhesive layer, and sample B in which the retort-processed packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined by 45 degrees from the normal direction of the sample B is incident on the surface of the sample B on the retort-treated packaging material side, and the regular reflection direction of incident light is set to 0 degree as a reference angle, and the reference angle is In the range of ± 15.0 degrees as the center, the intensity of the reflected light is measured every 0.1 degrees.

The details of the measurement conditions 1 and 2 are the same as the above-described screening method for a packaging material of the present invention.
Further, embodiments of formula (1), embodiments of the d _1, technical objections, technical objections d ₁ of the formula (1) is the same as the method of selecting packaging material of the present invention described above is there.

Further, the packaging material of the present invention, the angle indicating the 1/20 intensity of the intensity of the reflected light of the specular reflection direction of the packaging material were measured by the above measurement conditions 1 d _3, the packaging material was measured by the above measurement conditions 2 the angle indicating the 1/20 intensity of the intensity of the reflected light of the positive reflection direction upon the d _4, it is preferable to satisfy the following formula (2).
| (D ₃ −d ₄ ) / d ₃ | × 100 ≦ 15.0% (2)

  The embodiment of the formula (2) and the technical objection of the formula (2) are the same as those of the packaging material selection method of the present invention described above.

<Laminated structure>
The outline of the laminated structure of the thickness direction of the packaging material of this invention is shown in FIGS. 1-4, the upper side is the outer layer side, and the lower side is the inner layer side. The packaging material 1 is only required that at least the plastic film 2, the glossy printed layer 3a, and the sealant layer 4 are laminated in this order from the outer layer side, and may include other layers as constituent layers.
For example, as shown in FIGS. 1 to 4, an intermediate base material layer 5 may be provided between the glossy printed layer 3 a and the sealant layer 4 and laminated on both sides with an adhesive layer 6. Further, as shown in FIG. 2, the printed pattern layer 3b may be provided on the outer layer side of the glossy printed layer 3a, and as shown in FIG. 4, the printed pattern layer 3b is provided in parallel with the glossy printed layer 3a. You may do it. Moreover, as shown in FIG. 3, you may have the black ground color printing layer 3c in contact with the inner layer side of the glossy printing layer 3a. Moreover, as shown in FIG. 4, you may have the white ground color printing layer 3d in the inner layer side of the glossy printing layer 3a. Although not shown, a white ground color printing layer 3d may be provided on the inner layer side of the glossy printing layer 3a in FIGS. 1 to 3. Also, between the plastic film 2 and the glossy printing layer 3a, gloss printing A gas barrier layer (not shown) may be formed between the layer 3 a and the sealant layer 4.
Specifically, the packaging material of the present invention can be exemplified by the following laminated structure in order from the outer layer side. Note that “/” means the boundary of each layer.
(1) Plastic film / glossy printing layer / intermediate base material layer / sealant layer (2) Plastic film / gas barrier layer / glossy printing layer / sealant layer (3) Plastic film / gas barrier layer / glossy printing layer / intermediate base material layer / Sealant layer (4) Plastic film / glossy printing layer / gas barrier layer / intermediate base material layer / sealant layer In addition, from the viewpoint of making the glossy printing layer 3 visible from the outside, it is formed on the outer layer side of the glossy printing layer 3a. It is assumed that the layer has a light transmission property.

<Plastic film>
The plastic film 2 plays a role as a base material on the outer layer side of the packaging material 1 and is made of a light-transmitting material so that the glossy printed layer 3a can be visually recognized from the appearance.
Specifically, for example, polyolefin resins such as polyethylene (PE) and polypropylene (PP), cyclic polyolefin resins, polystyrene resins, acrylonitrile-styrene copolymer (AS) resins, acrylonitrile-butadiene-styrene copolymers. Polymer (ABS) resin, poly (meth) acrylic resin, polycarbonate resin, polyvinyl alcohol resin, ethylene-vinyl alcohol copolymer (EVOH), saponified ethylene-vinyl ester copolymer, polyethylene terephthalate (PET) Polyester resins such as polybutylene terephthalate (PBT) and polyethylene naphthalate (PEN), polyamide resins such as various nylons (Ny), polyurethane resins, acetal resins, cellulose resins, polyvinyl chloride Emissions-based resin (PVDC) and the like. The plastic film may be uniaxially stretched or biaxially stretched. Moreover, the composite film by which the 2 or more types of resin film of the above was laminated | stacked may be sufficient. These plastic films may be formed by an inflation method or a melt extrusion coating method.

The plastic film is preferably excellent in heat resistance from the viewpoint of heating in a microwave oven or retort treatment. Examples of the resin constituting the plastic film having excellent heat resistance include polyester resins and polyamide resins.
Specific examples of the plastic film having excellent heat resistance include a single film of a polyester film, a single film of a polyamide film such as nylon, and a composite film including at least one of a polyester film and a polyamide film. Examples of the composite film include PET / Ny / PET, and a coextruded stretched film having a PET / Ny configuration from the outer layer side. Moreover, as said composite film, it is also preferable to combine 1 or more types of a polyester film and a polyamide film, and 1 or more types of an ethylene-vinyl alcohol copolymer film and a polyvinylidene chloride film.

  The thickness of the plastic film 2 is not particularly limited and can be appropriately set according to the use of the packaging material 1, but is usually preferably about 5 to 50 μm, more preferably 10 to 40 μm, More preferably, it is 12-25 micrometers.

<Glossy printing layer>
The packaging material of this invention has the glossy printing layer containing a luster pigment between a plastic film and a sealant layer.
The gloss printing layer 3a may be provided on the entire surface of the packaging material as shown in FIGS. 1 to 3, or may be provided only on a part of the packaging material as shown in FIG. Moreover, as shown in FIG. 2, you may have the pattern printing layer 3b in a part of the outer layer side of the glossy printing layer 3a. Moreover, as shown in FIG. 4, you may have the glossy printing layer 3a and the pattern printing layer 3b in parallel in the same position of the thickness direction of a packaging material.
Moreover, you may form pictures, such as a character, a figure, a symbol, a pattern, a pattern, by the glossy printing layer 3a.

Examples of glitter pigments include pearl pigments and metal scales.
Among these, pearl pigments that can be easily inked without using a high boiling point solvent such as mineral spirit are preferable. Further, the pearl pigment can be easily imparted with resistance to microwave ovens, and is also preferable in that the shape and the like are not easily changed even by high retort treatment, and the formulas (1) and (2) are easily satisfied.
More specifically, the resistance to the microwave oven will be described. When the packaging material is processed by heat sealing, when the glitter pigment is a metal scale, the distance between the metal scales tends to be close at the time of heat sealing. In the material, the risk of occurrence of sparks by microwaves in the microwave oven increases. On the other hand, in the case of a pearl pigment, even if the distance between the pearl pigments is close at the time of heat sealing, the above-described danger does not occur when heating in a microwave oven.

The pearl pigment is a thin plate-like fine particle having a coating layer made of a high refractive index material such as titanium dioxide on the surface of mica (mica) scale-like fine particles, and has light transmittance. For this reason, when the thin plate-like fine particles are arranged in layers, the light is multiply reflected, and a glossy feeling like a metal or a pearl can be generated.
As described above, the pearl pigment is mainly composed of a metal oxide, not the metal itself, but is a colorant capable of producing a metallic luster.

There are several types of pearl pigments, and they can be roughly classified into three types: white pearl pigments, interference pearl pigments, and colored pearl pigments.
The white pearl pigment is a colorless high refractive index material such as titanium dioxide in the mica coating layer, and the coating layer has a relatively small thickness of about 0.1 to 0.15 μm. Appears to be white or silver.
In the interference pearl pigment, the coating layer of mica is a colorless high refractive index material such as titanium dioxide, and the thickness of the coating layer is larger than that of the white pearl pigment and exceeds 0.15 μm. Depending on the thickness, the reflected light and the transmitted light change, and various interference colors are generated. Sometimes called an iris colored pearl.
Colored pearl pigments are chromatic, with mica coating layer made of colored high refractive index materials such as ferric oxide, colored pearlescent materials such as ferric oxide around white pearl pigments or others Or a pigment coated with a colorant in the coating layer of mica.

The pearl pigment may be any of the above-mentioned types, but it is selected from white pearl pigments and interference pearl pigments from the viewpoint of obtaining a pearl coating color with higher brightness and giving a high-class feeling from all directions. It is preferable to include at least one selected from the group consisting of colored pearl pigments. As one or more types selected from white pearl pigments and interference pearl pigments, white pearl pigments are preferable, and as one or more types selected from colored pearl pigments, the coating layer of mica is colored with ferric oxide or the like. Those made of a high refractive index material and those coated with a colored high refractive index material around the white pearl pigment are preferred.
In this case, in particular, in order to obtain a deep golden gloss when viewed from any direction, a colored pearl pigment or mica coating layer in which the periphery of the white pearl pigment is coated with ferric oxide is used as the colored pearl pigment. It is preferable to use a colored pearl pigment in which is ferric oxide, and it is more preferable to use a white pearl pigment as one or more selected from a white pearl pigment and an interference pearl pigment.

  When using in combination one or more types (A) selected from white pearl pigments and interference pearl pigments and one or more types (B) selected from colored pearl pigments, A: B is a mass ratio, It is preferably 1: 0.2 to 1:20, more preferably 1: 0.5 to 1:15, and still more preferably 1: 1 to 1:10.

  The particle size of the pearl pigment is not particularly limited, and the average particle size is preferably 5 to 60 μm, more preferably 5 to 30 μm. In addition, the average particle diameter in this specification shall mean the average value of the major axis of arbitrary 20 particles observed with the optical microscope.

The content of the pearl pigment in the glossy printing layer is preferably 40% by mass or more and 90% by mass or less, more preferably 50% by mass or more and 85% by mass or less, and still more preferably 60% by mass. The mass is 80% by mass or more.
Even if the pearl pigment is added in a large amount in this way, it is preferable in that it can suppress the generation of sparks and local overheating when heated in a microwave oven. Moreover, by adding a large amount of the pearl pigment as described above, the pearl pigment can be made difficult to flow during the high retort treatment, and the formulas (1) and (2) can be easily satisfied.

Examples of the material of the metal scale include metals and alloys such as aluminum, gold, silver, brass, titanium, chromium, nickel, nickel chromium, and stainless steel.
For example, (i) the metal thin film formed by vacuum-depositing the metal or alloy on a plastic film is peeled from the plastic film, and the peeled thin metal film is pulverized and stirred. (Ii) the metal or alloy These powders and a solvent are mixed, and the powder is spread and / or pulverized with a medium stirring mill, a ball mill, an attritor or the like.

When metal scales are used as the glitter pigment, the metal scales produced by the method (i) are preferred from the viewpoint of easily satisfying the formulas (1) and (2).
On the other hand, the metal scales manufactured by the above method (ii) is a disadvantageous material from the viewpoint of satisfying the formulas (1) and (2). More specifically, the metal scales produced by the above method (ii) are scaled by stretching the metal powder, so that the surface of the metal scales is easily wrinkled. Distortion has accumulated. The shape of the metal scales produced by the above method (ii) is changed by releasing strain when the high heat is applied by the high retort treatment and restoring wrinkles generated on the surface. For this reason, the metal scale manufactured by the method (ii) is likely to change the intensity distribution of the reflected light by the high retort process. That is, the metal scale manufactured by the above method (ii) is difficult to satisfy the expressions (1) and (2).

The metal scales preferably have an average length of 1 to 50 μm, more preferably 2 to 30 μm, and even more preferably 5 to 20 μm.
By making the average length 1 μm or more, aggregation can be easily suppressed, and by making the average length 50 μm or less, it is difficult to contact with other metal scales when the metal scales are inclined in the glossy printed layer. it can.

The metal scales preferably have an average thickness of 0.01 to 5 μm, more preferably 0.02 to 3 μm, and even more preferably 0.05 to 1 μm.
By making the average thickness 0.01 μm or more, it is easy to improve the handleability and the metallic luster, and by making the average thickness 5 μm or less, the metal scales are inclined in the glossy printed layer, so that the interval between the metal scales is narrowed. This can be suppressed.
The metal scale has an aspect ratio defined by [average length / average thickness] of preferably 50 to 500, more preferably 60 to 450, and even more preferably 70 to 400. .

Let the average length and average thickness of a metal scale be an average value of 20 metal scales. In addition, the length and thickness of each metal scale can be measured by using a laser interference type three-dimensional shape analysis apparatus in a state where the metal scale is dispersed on a smooth substrate. The length of the individual metal scale means the maximum diameter when the individual metal scale is observed from a plane in an arbitrary direction, and the thickness of the individual metal scale is the thickness when the individual metal scale is observed from the cross-sectional direction. It means the maximum thickness. In addition, the maximum diameter when each metal scale is observed from a plane in an arbitrary direction is intended to unify the direction in which the maximum diameter of each metal scale is measured. For example, when the X-axis direction on the screen obtained by image processing of the measurement result of the three-dimensional shape analyzer is an arbitrary direction (measurement direction), the maximum diameter is measured in a direction parallel to the X-axis. Even if there is a maximum diameter in a direction that is not parallel to the X axis, it is not regarded as the maximum diameter.
Examples of the laser interference type three-dimensional shape analysis apparatus include a trade name “Shape Analysis Laser Microscope VK-X Series” manufactured by Keyence Corporation.

  The content of the metal scale in the glossy printed layer is 3% by mass or more and less than 40% by mass of the total solid content of the glossy printed layer from the viewpoint of suppressing the occurrence of sparks and local overheating when heated in a microwave oven. It is preferable that it is 10 mass% or more and 30 mass% or less.

The glossy printed layer preferably contains 0.5% by mass or less of a black pigment.
By containing a small amount of black pigment in the glossy printed layer, the black pigment absorbs the light that was not reflected by the bright pigment present in the vicinity of the surface layer and suppresses diffuse reflection on the inner layer side of the glossy printed layer. And metallic luster can be improved.
In particular, when the glitter pigment is a pearl pigment, the inclusion of a small amount of black pigment in the glossy printed layer suppresses the reflection of the complementary color transmitted through the pearl pigment on the inner layer side of the glossy printed layer. A pearl coating color can be obtained.

  The content of carbon black in the glossy printed layer is preferably 0.5% by mass or less, more preferably 0.1% by mass or less, and further preferably 0.01% by mass or less. Further, the lower limit of the content of carbon black in the glossy printed layer is preferably 0.0001% by mass or more from the viewpoint of easily obtaining a deep pearl coating color.

  Examples of the black pigment include carbon black and titanium black. Moreover, the black pigment which has the near-infrared reflectivity or near-infrared transmissivity mentioned later can also be used.

The average primary particle diameter of the black pigment is preferably 0.1 μm or more, more preferably 0.2 μm or more, from the viewpoint of enhancing the absorbability in the visible light region. The upper limit of the average primary particle diameter of the black pigment is not particularly limited, but is preferably 3.0 μm or less, more preferably 2.0 μm or less, and further preferably 1.0 μm or less.
The average primary particle diameter of the black pigment is obtained as a mass average value d50 in the particle size distribution measurement by a laser light diffraction method.

The glossy printed layer preferably contains a colorant other than a black pigment in order to improve design properties.
Examples of the colorant include general-purpose dyes and pigments (for example, inorganic pigments such as chrome yellow, titanium yellow, petal, cadmium red, ultramarine, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue) ) Can be used.

  The content of the colorant is preferably 10 to 70 parts by mass, more preferably 20 to 60 parts by mass, and still more preferably 30 to 50 parts by mass with respect to 100 parts by mass of the metal scale. .

The glossy printed layer preferably contains inorganic particles having an average primary particle diameter of 1 to 100 nm (hereinafter sometimes referred to as “inorganic fine particles”).
By containing inorganic fine particles in the glossy printed layer, it is possible to make it difficult for the glittering pigment to flow in the glossy printed layer during the high retort treatment, and to easily satisfy the formulas (1) and (2). . In particular, when the glitter pigment is a metal scale, inorganic fine particles are effective.
The average primary particle diameter of the inorganic fine particles is more preferably 2 to 50 nm, and further preferably 5 to 30 nm. The average primary particle diameter of the inorganic fine particles is obtained as a mass average value d50 in the particle size distribution measurement by a laser light diffraction method.

  The content of the inorganic fine particles in the glossy printing layer is preferably 10 to 70 parts by mass, more preferably 15 to 50 parts by mass, with respect to 100 parts by mass of the glitter pigment. More preferably.

  Examples of the inorganic fine particles include silica, alumina, zirconia and titania. Among these, silica excellent in transparency is preferable. Moreover, since silica and alumina are excellent in insulation, they are also preferable in terms of improving microwave resistance.

  The thickness of the glossy printed layer is preferably 1 to 10 μm, more preferably 1.5 to 5 μm, from the viewpoint of sufficiently impressing metallic gloss.

The glossy print layer 3a, the pattern print layer 3b, the black background color print layer 3c, and the white background color print layer 3d (hereinafter sometimes collectively referred to as “print layer”), for example, are plastic films. 2 and the sealant layer 4 can be formed using a known ink by a known printing method such as a gravure printing method, an offset printing method, a relief printing method, or a silk screen printing method.
The printing layer is preferably formed by back printing on the inner layer side surface of the plastic film 2 or the gas barrier layer. Alternatively, it may be formed by surface printing on the outer layer side surface of the intermediate base material layer 5 or the sealant layer 4 and then being bonded to the plastic film 2 or the gas barrier layer via an adhesive layer. . In addition, the entire surface of the packaging material 1 or partial printing may be used.

  The ink of the printing layer is usually composed mainly of a vehicle composed of a binder resin and a solvent, and added with a colorant such as a dye or a pigment. (The glossy printing layer 3a must have a glitter pigment. As an ingredient). The colorants for the printing layer may be used alone or in combination of two or more.

  Examples of the binder resin include polyolefin resins such as polyethylene resins and chlorinated polypropylene resins, poly (meth) acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, and vinyl chloride-vinyl acetate copolymers. , Polystyrene resin, styrene-butadiene copolymer, vinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polybutadiene resin, polyester resin, polyamide resin, alkyd resin, epoxy Resin, unsaturated polyester resin, thermosetting poly (meth) acrylic resin, melamine resin, urea resin, polyurethane resin, phenol resin, xylene resin, maleic acid resin, nitrocellulose, ethyl cellulose, acetyl butyl Le cellulose, cellulose resins such as ethyl oxy ethyl cellulose, rubber and cyclized rubber rubber resin chloride, petroleum resin, rosin, and natural resins such as casein, and the like.

In addition, the binder resin of the glossy print layer suppresses the flow of the glitter pigment in the glossy print layer during high retort, and has a melting point of 130 ° C. or higher from the viewpoint of easily satisfying the formulas (1) and (2). Some are preferred.
The melting point of the binder resin in the glossy printing layer is more preferably 140 ° C. or higher, and further preferably 150 ° C. or higher.
In the present specification, a resin having a melting point of AA ° C. or higher includes a resin whose melting point is observed at AA ° C. or higher, as well as a resin whose melting point is less than AA ° C. and whose melting point is not observed at AA ° C. or higher. Shall be.

  For the printing layer forming ink, if necessary, for example, a light stabilizer such as a filler, a stabilizer, a plasticizer, an antioxidant, an ultraviolet absorber, a dispersant, a thickener, a drying agent, a lubricant, Arbitrary additives, such as an antistatic agent and a crosslinking agent, can be added.

As a solvent contained in the ink of the printing layer, a solvent used in a normal pigment ink can be applied, for example, an alcohol solvent such as methanol, ethanol, normal propanol, isopropanol, propylene glycol monomethyl ether, acetone or methyl ethyl ketone. , Ketone solvents such as methyl isobutyl ketone, ester solvents such as methyl acetate, ethyl acetate, and normal propyl acetate, aliphatic hydrocarbon solvents such as normal hexane, normal heptane, and normal octane, cyclohexane, methylcyclohexane, cycloheptane, etc. Alicyclic hydrocarbon solvents, aromatic solvents such as toluene and xylene, mineral spirits and the like. These may be used alone or in combination of two or more.
Among these, it is preferable not to contain an aromatic solvent from the viewpoint of the working environment at the time of printing and food hygiene.

In general, in ink containing metal scales such as aluminum paste, the solvent contains mineral spirit, but the mineral spirit has a high boiling point of 162 to 192 ° C. at 1 atm. Even when applied, it is difficult to completely volatilize and remove, and even with a slight residual amount, the manufactured packaging material may produce a solvent odor. It is not preferable for the packaging material to generate such a solvent odor. In particular, when the article to be packaged by the packaging material is a food, it is required that the solvent odor is not generated as much as possible.
For this reason, it is not preferable to use a high boiling point solvent such as mineral spirit as the solvent used in the ink for forming the printing layer, and the boiling point at 1 atm is preferably 150 ° C. or less, more preferably 130. ° C or lower, more preferably 120 ° C or lower.

<Pattern printing layer>
The packaging material of the present invention may have a pattern printing layer 3 b between the plastic film 2 and the sealant layer 4. The pattern print layer 3b can be formed, for example, on the outer layer side of the glossy print layer 3a (FIG. 2), or can be formed in parallel with the glossy print layer 3a at the same position in the thickness direction of the packaging material ( FIG. 4).

The pattern print layer 3b may be a print layer formed from a color that can be distinguished from the glossy print layer 3a, and is a wide concept including characters, figures, symbols, patterns, patterns, solid prints, and the like. The coloring agent for the pattern printing layer 3b is a general-purpose dye or pigment (for example, inorganic pigments such as chrome lead, titanium yellow, petal, cadmium red, ultramarine, cobalt blue, quinacridone red, isoindolinone yellow, phthalocyanine blue, etc. Organic pigments or dyes) can be used.
The thickness of the pattern print layer is not particularly limited, and is preferably about 1.5 to 5 μm, more preferably 1.5 to 3 μm.

<Black ground color printing layer>
In the case where the glitter pigment is a pearl pigment, from the viewpoint of imparting a depth and profound feeling to the metallic luster due to the pearl pigment, as shown in FIG. 3, the black ground color printing layer 3c is in contact with the inner layer side of the gloss printing layer 3a. Is preferably provided.
The black ground color printing layer preferably has an L ^* value of L ^* a ^* b ^* color system of International Lighting Commission (CIE) standard measured in accordance with JIS Z8781-4: 2013 of 20 or less. More preferably, it is 10 or less.
The black ground color print layer may be formed on the entire surface of the portion having the glossy print layer, or may be formed only on a part of the portion having the glossy print layer. When the black ground color print layer is formed on the entire surface of the portion having the glossy print layer, the above-described effects can be obtained on the entire surface of the glossy print layer. Moreover, when a black ground color printing layer is formed in a part of the location which has a glossy printing layer, a metallic gloss change can be provided in-plane. The black ground color printing is preferably monochromatic solid printing.

  The thickness of the black ground color printing layer is not particularly limited as long as the metallic luster of the glossy printing layer 3a by the pearl pigment can be emphasized, and is preferably about 1.5 to 5 μm, More preferably, it is 1.5-3 micrometers.

Although the formation method of a black ground color printing layer is not specifically limited, It can form by printing with the printing system mentioned above with the ink which used black dye, a pigment, etc. as a coloring agent. The black colorant is preferably a black pigment from the viewpoint of developing a stable black color as the background color.
As the black pigment of the black ground color printing layer, a black pigment having near infrared reflectivity or near infrared transmittance is preferable. The black pigment having near-infrared reflectivity includes manganese, which includes a complex oxide containing at least one metal element other than manganese. The black pigment having near-infrared transmittance includes azomethine azo Examples thereof include pigments and perylene pigments.

Since the composite oxide has near-infrared reflection characteristics, the packaging material 1 provided with the black ground color printed layer can also have heat retention characteristics of an object to be packaged.
One kind of metal element other than manganese contained in the composite oxide may be used alone, or two or more kinds may be used in combination. Examples of metal elements other than manganese contained in the composite oxide include Group 2 elements such as calcium and barium; Group 3 elements such as yttrium, lanthanum, praseodymium and neodymium; Group 4 elements such as titanium and zirconium; Examples include Group 13 elements such as boron, aluminum, gallium, and indium; and metal elements such as Group 15 elements such as antimony and bismuth. Among these, a Group 2 element, a Group 4 element, and a Group 15 element are preferable, calcium, titanium, and bismuth are more preferable, and calcium and titanium are further preferable. As a particularly preferable specific example of the composite oxide, a composite oxide containing manganese, calcium, and titanium can be given.
The structure of the composite oxide is not particularly limited, but is preferably a perovskite structure, an orthorhombic structure, a hexagonal structure, or the like from the viewpoint of a stable structure or its color development, and is a perovskite structure. Is more preferable.
Manganese-based composite oxides are described in, for example, WO2016 / 125906A1.

The azomethine azo pigment has a diazonium group which is a reaction compound of tetrachlorophthalimide and aminoaniline.
The perylene pigment is a pigment having a structure in which two oxygen atoms constituting the six-membered ring of perylenetetracarboxylic dianhydride are removed, and examples include perylene black.

  The average particle diameter of the black pigment in the black ground color printing layer can be in the same range as the average particle diameter of the black pigment in the glossy printing layer.

  The content of the black pigment in the black ground color printing layer is 10 to 50% by mass of the total solids constituting the black ground color printing layer from the viewpoint of conspicuous metallic luster and the balance of coating film strength. The content is preferably 15 to 45% by mass, more preferably 20 to 40% by mass.

  As the black pigment of the black ground color printing layer, a general-purpose black pigment such as carbon black or titanium black can be used. However, in general-purpose black pigments such as carbon black and titanium black, when the packaging material 1 is for a microwave oven, a portion where the carbon black or titanium black or the like is present is locally overheated by microwaves in the microwave oven. This may cause a hole in the packaging material. For this reason, cautions such as suppressing the content of general-purpose black pigments such as carbon black and titanium black are required when used for microwave ovens.

<White ground color printing layer>
As shown in FIG. 4, the packaging material of the present invention preferably has a white ground color printing layer 3d on the inner layer side of the glossy printing layer 3a. By forming the white ground color printing layer, the appearance of the package can be improved depending on the type of the package. In addition, when it has the black ground color printing layer mentioned above, it is preferable to form a white ground color printing layer in an inner layer side rather than a black ground color printing layer. The white ground color printing layer is preferably formed by monochromatic solid printing.

The white ground color printing layer may be formed only on a part of the surface of the packaging material, but from the viewpoint of easily exerting the above-described effect, as shown in FIG. It is preferable to form. A general-purpose white pigment can be used for the colorant of the white ground color printing layer. In addition, in order to adjust the color of a white ground color printing layer, you may use dyes and pigments other than a white pigment as a coloring agent.
The thickness of the white ground color printing layer is not particularly limited, and is preferably about 1.5 to 5 μm, more preferably 1.5 to 3 μm.

<Sealant layer>
The sealant layer 4 has a role of protecting the article to be packaged by directly contacting the inner layer side surface with the article to be packaged. In particular, when a liquid packaging container is formed with the packaging material 1, the sealant layer 4 is preferably made of a material that does not allow the liquid to penetrate. Moreover, it is preferable that the innermost layer of the sealant layer 4 has heat sealability for pouching.

  Examples of the material constituting the sealant layer 4 include low density PE (LDPE), linear low density PE (LLDPE), medium density PE (MDPE), high density PE (HDPE), and ethylene-vinyl acetate copolymer. And polyolefin resins such as a propylene homopolymer, an ethylene-propylene block copolymer, and an ethylene-propylene random copolymer, and one or more of these resins can be used. The sealant layer 4 may be composed of a single layer or may be composed of two or more layers. The sealant layer is preferably an unstretched film made of the above-described resin in order to suppress shrinkage during heat sealing.

In order to increase heat resistance from the viewpoint of heating in a microwave oven or retort treatment, the sealant layer is preferably composed of a resin having excellent heat resistance. Specifically, propylene homopolymer, ethylene-propylene block copolymer Polymers, propylene resins such as ethylene-propylene random copolymers, and HDPE are preferred.
Moreover, it is preferable to use properly the said propylene-type resin according to the objective. Specifically, an ethylene-propylene block copolymer is preferable when importance is attached to cold resistance (for example, a packaging material for frozen food), and an ethylene-propylene random copolymer is preferable when importance is placed on transparency. When importance is attached to propylene, a propylene homopolymer is preferred. In the case of a container equipped with an automatic steaming mechanism, an ethylene-propylene block copolymer is preferred from the viewpoint that it is possible to easily remove steam by reducing the sealing strength at high temperatures.

Moreover, when the lid | cover of a container with a lid | cover is formed with the packaging material 1, it is preferable that the sealant layer 4 has an easy peel property.
The easy peel property is, for example, a characteristic that when the sealant layer 4 of the packaging material 1 of the lid of the lidded container is joined to the container body, the lid body is easily peeled from the container body when the lidded container is opened. Say.
The sealant layer having an easy peel property uses two or more kinds of resins, and one resin (resin having good adhesion to the container body) and another resin (adhesion to the container body are not good) It can be formed by mixing one resin and an incompatible resin. Since such a resin differs depending on the material of the container, it cannot be generally stated. However, when the container is formed of PP, PP that is one resin (resin having good adhesion to the container body) and other resin By forming a sealant layer from a resin mixed with at least one selected from PE, polybutene, and polystyrene, which is a resin (adhesiveness with the container body is not good and is incompatible with the one resin), Easy peel properties can be imparted to PP containers.
In addition, you may give an easy peel property only to the side (innermost layer in a packaging material) joined to the container main body of a sealant layer by making a sealant layer into a multilayer structure.

  The thickness of the sealant layer 4 is not particularly limited, and is appropriately set according to the use of the packaging material 1 and the type and nature of the packaged object, but is usually preferably about 10 to 200 μm. In the case of a pouch (particularly a retort pouch), the thickness of the sealant layer 4 is more preferably 20 to 150 μm, and further preferably 30 to 100 μm. In the case of a container with a lid, the thickness of the sealant layer 4 is more preferably 15 to 80 μm, and further preferably 20 to 60 μm.

<Gas barrier layer>
The gas barrier layer can be provided anywhere between the plastic film 2 and the sealant layer 4 as necessary. The gas barrier layer plays a role of blocking permeation of oxygen, water vapor, and the like between an object to be packaged by the packaging material 1 and the external environment of the packaging material 1. Moreover, you may provide the light-shielding property which interrupt | blocks permeation | transmission of visible light, an ultraviolet-ray, etc. The gas barrier layer may be composed of only one layer or may be composed of two or more layers.
When the gas barrier layer is formed on the outer layer side of the glossy printed layer 3a, it is made of a light-transmitting material so that the glossy printed layer 3a can be visually recognized from the appearance, like the plastic film 2.

  The gas barrier layer can be formed as a vapor deposition film or a coating film by a known method. The surface on which the gas barrier layer is formed may be subjected to surface treatment in advance from the viewpoint of improving the adhesion of the gas barrier layer. Examples of the surface treatment include corona discharge treatment, ozone treatment, low temperature plasma treatment using oxygen gas or nitrogen gas, glow discharge treatment, oxidizing agent treatment, application of an anchor coating agent, and the like.

[Deposited film]
As a vapor deposition film which is an example of the gas barrier layer, for example, silicon (Si), aluminum (Al), magnesium (Mg), calcium (Ca), potassium (K), tin (Sn), sodium (Na), boron ( B), titanium (Ti), lead (Pb), zirconium (Zr), yttrium (Y), or other inorganic substances or oxides thereof. Among these, when the packaging material is for a microwave oven, silicon oxide, aluminum oxide, magnesium oxide, etc., from the viewpoint of sufficiently heating the food to be packaged with microwaves in the microwave oven Inorganic oxides are preferred.
Examples of the method for forming the deposited film include physical vapor deposition (PVD) methods such as vacuum deposition, sputtering, and ion plating, and chemical vapor deposition (CVD) such as plasma chemical vapor deposition, thermal chemical vapor deposition, and photochemical vapor deposition. Law.

  Although the film thickness of a vapor deposition film changes with forming materials, the required gas barrier performance, etc., it is usually preferable that it is about 5-200 nm, More preferably, it is 5-150 nm, More preferably, it is 10-100 nm. In the case of inorganic oxides such as silicon oxide and aluminum oxide, the thickness is preferably about 5 to 100 nm, more preferably 5 to 50 nm, and still more preferably 10 to 30 nm.

[Gas barrier coating film]
Examples of the gas barrier coating film which is an example of the gas barrier layer include, for example, a general formula R ¹ _n M (OR ² ) _m (wherein R ¹ and R ² are organic groups having 1 to 8 carbon atoms, and M is a metal atom). N is an integer of 0 or more, m is an integer of 1 or more, and n + m is a valence of M.), a polyvinyl alcohol-based resin and / or ethylene-vinyl. A coating solution obtained by polycondensation of an alcohol copolymer with a sol-gel method in the presence of a sol-gel method catalyst, acid, water, and an organic solvent is applied, and at 0 to 50 ° C., 0 It can be formed by heat treatment for 0.05 to 60 minutes.
As a coating method, for example, it can be performed by a coating means such as roll coating such as a gravure roll coater, spray coating, spin coating, dipping, brush, bar coating, applicator and the like. It is preferable that the coating film has a dry film thickness of about 0.01 to 30 μm, more preferably 0.05 to 20 μm, and still more preferably 0.1 to 10 μm by one or more times of application.
The gas barrier coating film is preferably formed on the surface of the deposited film from the viewpoint of improving the gas barrier property.

Considering the specific configuration of the gas barrier layer, the packaging materials of the present invention can be exemplified by the following laminated configurations (1 ′) to (4 ′) in order from the outer layer side. Note that “/” means the boundary of each layer.
(1 ') Plastic film / deposited film / glossy printed layer / sealant layer (2') Plastic film / deposited film / gas barrier coating film / glossy printed layer / sealant layer (3 ') plastic film / glossy printed layer / deposited film / Intermediate base material layer / Sealant layer (4 ') Plastic film / Glossy printed layer / Gas barrier coating film / Vapor deposition film / Intermediate base material layer / Sealant layer

<Intermediate base material layer>
The intermediate base material layer is used to improve the strength and processability of the packaging material 1 and to change the texture of the packaging material, or to be used as a base material for forming other layers, as necessary. It is a layer provided. Examples of the constituent material of the intermediate base material layer include a plastic film and paper.
In the case of a plastic film, the same plastic film as described above formed on the outer layer side of the glossy printed layer 3a can be used.
In the case of paper, the packaging material 1 can be imparted with characteristics such as formability, bending resistance and rigidity. For example, high-size bleached or unbleached kraft paper, pure white roll paper, paperboard, Processed paper or the like can be used. The basis weight of the paper is usually preferably about 50 to 600 g / m ² , more preferably 60 to 500 g / m ² , and still more preferably 70 to 450 g / m ² . When the packaging material 1 is used for soft packaging, it is preferably less than 150 g / m ² , and when used for paper containers such as paper cups and liquid paper containers, it is preferably 200 g / m ² or more.

  From the viewpoint of heating in a microwave oven or retort treatment, in order to increase heat resistance, the intermediate base material layer is preferably excellent in heat resistance. Specific examples of the intermediate base material layer having excellent heat resistance include plastic films exemplified as plastic films for packaging materials for microwave ovens and retort containers, and paper.

<Adhesive layer>
In the packaging material 1, each structural layer may be laminated | stacked through the adhesive bond layer 6 from a viewpoint of the improvement of the joint strength between each layer. The adhesive layer can be formed by a method using a known dry laminating adhesive.
Examples of dry laminate adhesives include polyvinyl acetate adhesives, polyacrylate adhesives, cyanoacrylate adhesives, ethylene copolymer adhesives, cellulose adhesives, polyester adhesives, and polyamide adhesives. Adhesives, polyimide adhesives, amino resin adhesives such as urea resins and melamine resins, phenol resin adhesives, epoxy adhesives, polyurethane adhesives (for example, cured products of polyols and isocyanate compounds), reactions Examples thereof include type (meth) acrylic acid adhesives, rubber adhesives such as chloroprene rubber, nitrile rubber, and styrene-butadiene rubber, silicone adhesives, inorganic adhesives such as alkali metal silicates and low-melting glass.

<Thermosoftening resin layer>
As shown in FIG. 11, the packaging material 1 may have a thermosoftening resin layer 7 in a partial region between the plastic film and the sealant layer.
As shown in FIG. 11, the thermosoftening resin layer 7 is formed in a part near the edge of the packaging material 1, and the thermosoftening resin layer has a predetermined strength in a temperature environment below room temperature. In addition, it is composed of a resin whose predetermined strength is lowered in a high temperature environment, and when heated in a microwave oven and the pressure in the packaging container rises, a part of the sealant layer is destroyed and a heat softening resin Part of the layer can delaminate or cohesive and escape the vapor. Details will be described in the second embodiment of the automatic steaming mechanism.

  A thermosoftening resin, that is, a resin having a predetermined strength in a temperature environment below room temperature but having a predetermined strength reduced in a high temperature environment, has a melting point of 60 to 110 ° C., preferably a melting point of 60 to 90 ° C. Examples thereof include ethylene-vinyl acetate copolymer resin, polyamide, nitrified cotton and polyethylene wax, and a mixed resin of polyamide, nitrified cotton and polyethylene wax is preferable. As the resin containing polyamide, nitrified cotton, and polyethylene wax, MWOP varnish (softening point: 105 ° C.) manufactured by DIC Graphics Co., Ltd. can be used.

  The thickness of the thermosoftening resin layer is preferably 1 to 5 μm. By setting the thickness of the thermosoftening resin layer to 1 μm or more, the thermosoftening resin layer and the sealant layer can be easily broken when heated in a microwave oven. In addition, by setting the thickness of the heat-softening resin layer to 5 μm or less, when a film-shaped packaging material is wound into a roll shape, it is possible to suppress a rise in a part and an expansion of the packaging material in that part.

[Packaging container]
The packaging container of the present invention is at least partially formed of the packaging material.
By forming with the said packaging material, even if the metal itself is not used, the packaging container with a high-class feeling by metallic luster is obtained.
The packaging material only needs to be applied to a desired portion where a metallic luster is desired, and even if the entire packaging container is formed of the packaging material, or the packaging material is used only in part. May be.

The type and application of the packaging container of the present invention are not particularly limited, but when selling the contents contained in the packaging container, it is possible to impress the purchaser with a high-class feeling of the contents. For example, it can be suitably used for food containers and cosmetic containers.
Examples of the packaging container include a pouch and a container with a lid, as well as a cup and a tray. These packaging containers partially include the packaging material described above. That is, these packaging containers may be formed of a packaging material containing paper as an intermediate base material layer.
The specific shape of the pouch includes, for example, the shape of a microwave oven pouch shown in FIG. The pouch may be a retort container (a container sterilized at high temperature and high pressure), and may be a packaging container for a microwave oven or a container other than a retort container.
As a specific shape of the container with a lid, it has a configuration comprising a container body having a housing part and a lid body joined to the container body so as to seal the housing part, The thing formed with the packaging material is mentioned.
The packaging container can be suitably used for a microwave oven as described above. The packaging container can also be used as a retort container. Of course, the packaging container can also be used as a retort container for a microwave oven.

When a packaging container is a container for microwave ovens and a retort container, it is preferable that the packaging material which comprises a container shall be set as the laminated structure in any one of (1)-(4) mentioned above.
At this time, as the plastic film, it is preferable to use a single film of a polyester film, a single film of a polyamide film such as nylon, or a composite film including at least one of a polyester film and a polyamide film.
At this time, as the intermediate substrate, it is preferable to use a simple substance of a polyester film, a simple substance of a polyamide film such as nylon, a composite film containing at least one of a polyester film and a polyamide film, and paper.
In this case, the sealant layer is preferably a propylene resin such as a propylene homopolymer, an ethylene-propylene block copolymer, an ethylene-propylene random copolymer, or HDPE.
More specifically, in the case of a retort container or a microwave oven container, the packaging material constituting the container preferably has a laminated structure of any one of (A1) to (A12) below. Note that “/” means the boundary of each layer. In (A1) to (A12), it is preferable that PET and Ny are stretched films.

(A1) PET / glossy printed layer / Ny / ethylene-propylene block copolymer (A2) PET / gas barrier layer / glossy printed layer / Ny / ethylene-propylene block copolymer (A3) PET / glossy printed layer / gas barrier layer / Ny / ethylene-propylene block copolymer (A4) PET / glossy printed layer / PET / ethylene-propylene block copolymer (A5) PET / gas barrier layer / glossy printed layer / PET / ethylene-propylene block copolymer ( A6) PET / glossy printed layer / gas barrier layer / PET / ethylene-propylene block copolymer (A7) coextruded stretched film (PET / Ny / PET) PET / glossy printed layer / PET / ethylene-propylene block copolymer ( A8) Coextrusion stretched film (PET / Ny / PET) / Gas barrier layer / Sawa printing layer / PET / ethylene-propylene block copolymer (A9) co-extrusion stretched film (PET / Ny / PET) / glossy printing layer / gas barrier layer / PET / ethylene-propylene block copolymer (A10) PBT / gloss Printing layer / Ny / ethylene-propylene block copolymer (A11) PBT / gas barrier layer / gloss printing layer / Ny / ethylene-propylene block copolymer (A12) PBT / gloss printing layer / gas barrier layer / Ny / ethylene-propylene Block copolymer

In the case of a container for a microwave oven, the ethylene-propylene block copolymer that is the sealant layer of (A1) to (A12) may be a polyethylene resin such as LDPE, LLDPE, MDPE, HDPE.
In addition, when adopting the configuration of the automatic vaporization mechanism of the second embodiment described later in the container for the microwave oven, the above-described thermosoftening resin layer should be formed in a part between the plastic film and the sealant layer. That's fine.

(Pouch)
In FIG. 5, an example of the pouch which is one Embodiment of the packaging container of this invention is shown. The pouch 10 in FIG. 5 is for a microwave oven, and is a standing type pouch formed by heat-sealing the body 11 and the bottom 12. As shown in FIG. 5, the trunk | drum 11 contains a pair of main surface sheet | seat 13 which consists of the front main surface sheet | seat 13a and the back main surface sheet | seat 13b arrange | positioned facing each other, and was superimposed on a pair of main surface The vicinity of the side edge 14 of the sheet 13 is heat-sealed. A bottom sheet 16 that forms the bottom 12 is disposed between the lower edges 15 of the pair of main sheet 13.
And the accommodation space 17 which accommodates the content is formed in the area | region enclosed by a pair of main surface sheet | seat 13 and the bottom face sheet | seat 16. FIG. The bottom sheet 16 is bent convexly toward the accommodation space 17, and the vicinity of the periphery thereof is heat-sealed together with the lower part of the overlapping main sheet 13. When the bottom sheet 16 maintains the shape of the lower end of the pair of main sheet 13, the pouch 10 is provided with a self-supporting property and can be a standing pouch.
In the pouch 10 of FIG. 5, an opening 19 is formed between the upper edge 18 of the front main surface sheet 13 a and the back main surface sheet 13 b, and the contents can be accommodated from the opening 19. After containing the contents, the packaging container can be sealed by heat-sealing the vicinity of the upper edge 18 where the opening 19 is formed. When taking out the contents from the pouch 10, the vicinity of the upper edge 18 is torn from the notch 23 and opened.

The front main surface sheet 13 a, the back main surface sheet 13 b, and the bottom surface sheet 16 of the pouch 10 can be formed by the packaging material 1. All of these sheets may be formed of the packaging material 1 having the glossy printed layer 3a containing the pearl pigment, or only one of the sheets requiring metal glossiness may be formed of the packaging material 1. Good. In FIG. 5, it is shown that the front main surface sheet 13a is formed of the packaging material 1 having a laminated structure as shown in FIG. 2 so as to have the gloss print layer 3a and the pattern print layer 3b.
In addition, the sheet | seats other than the sheet | seat in which the packaging material 1 is used can use the thing in which the glossy printed layer 3a containing a pearl pigment is not formed in the packaging material 1, or a printing layer is not included, for example.

(Automatic steaming mechanism)
When the container is for a microwave oven, when the pressure in the pouch rises due to steam generated by cooking food, etc., the contents of the container automatically release the steam inside the storage space to prevent the pouch from bursting. It is preferable to have an automatic steaming mechanism. The automatic steaming mechanism is preferably formed near the periphery of the container.

A first embodiment of the automatic steaming mechanism will be described with reference to FIG. The microwave oven pouch shown in FIG. 5 has a first unsealed region 21 that is not heat-sealed in the vicinity of the side edge 14 near the upper side of the container (pouch). The first unsealed region 21 reaches the side edge 14 and has an opening 22. In addition, the first unsealed region 21 protrudes toward the accommodation space 17 side. Moreover, the heat seal part 25 projects to the accommodation space 17 side so as to surround the first unsealed region 21 projecting to the accommodation space 17 side, thereby forming an overhang part 25a. More specifically, the first unsealed region 21 and the accommodation space 17 are separated from each other, and an overhang portion 25a is formed so as to be connected to a heat seal portion 25 for sealing the pouch. .
The microwave oven pouch shown in FIG. 5 is formed by the automatic steaming mechanism 20 by the opening 22, the first unsealed region 21 and the heat seal portion (projected portion 25a) projecting toward the accommodation space 17 as described above. Has been. Specifically, when the pressure in the container rises due to heating, the location of the overhanging portion 25a in the heat seal portion 25 is subjected to a strong load, and the location of the overhanging region 25 is peeled off first. The space 17 and the first unsealed region 21 communicate with each other so that steam can escape to the outside.
Further details of the automatic steaming mechanism of the type shown in FIG. 5 are described in JP2015-120550A, JP2016-74457A, and JP2016-74458A.

  In the container 10 shown in FIG. 5, a second unsealed region 23 is formed on the side edge 14 opposite to the first unsealed region 21. The second unsealed region 23 is formed from the viewpoint of improving the yield of forming the opening 22 in the first unsealed region 21 when the plurality of retort containers 10 are continuously formed and then cut one by one. It does not necessarily have to be formed.

A second embodiment of the automatic steaming mechanism will be described with reference to FIGS.
The packaging container (pouch) 10 shown in FIG. 12 has an edge of the packaging material (a packaging material between the plastic film and the sealant layer and having a thermosoftening resin layer in a part near the edge) shown in FIG. The periphery of the part is heat sealed and pouched. Moreover, FIG. 13 is sectional drawing in XI-XI of the heat seal part 25 around the edge part of the packaging container 10 of FIG.
As shown in FIG. 12, the thermosoftening resin layer 7 is formed from the inner edge to the outer edge of the heat seal portion 25 for sealing the pouch in at least a part of the heat seal portion 25 of the packaging container 10. It will be necessary. The thermosoftening resin layer 7 provided at such a position is heated by a microwave oven and becomes high temperature, so that its strength is lowered.
As shown in FIG. 13, the heat-softening resin layer 7 is heated in a microwave oven or the like, and when the internal pressure is increased by the expansion of air in the packaging container 10 or water vapor contained in the contents, the vicinity of the inner edge of the heat seal portion 25. Starting from an arbitrary portion “A” of the sealant layer 4, a part of the sealant layer 4 is broken, and a part of the thermosoftening resin layer 7 is delaminated or coherently broken (the broken line B represents a sealant). An imaginary line where the layer 4 breaks and an imaginary line where the thermosoftening resin layer 7 peels or cohesively breaks down are shown. As a result, air and water vapor are removed from the destruction location, and the internal pressure of the packaging container 10 can be reduced.
Note that the automatic steaming mechanism of the second embodiment can also be applied to a lidded container described later.

  As the packaging material constituting the container having the second embodiment of the automatic steaming mechanism, it is preferable to select a resin that easily collapses as the resin constituting the sealant layer. Specifically, LLDPE is preferable. Moreover, it is preferable that the packaging material which comprises the container provided with 2nd embodiment of the automatic steaming mechanism is set as the laminated structure in any one of following (B1)-(B6). Note that “/” means the boundary of each layer. Moreover, in (B1)-(B6), it is preferable that PET and Ny are stretched films.

(B1) PET / Glossy printing layer / Heat softening resin layer / LLDPE
(B2) PET / gas barrier layer / glossy printed layer / thermosoftening resin layer / LLDPE
(B3) PET / glossy printed layer / gas barrier layer / thermosoftening resin layer / LLDPE
(B4) Ny / Glossy printed layer / Heat-softening resin layer / LLDPE
(B5) Ny / gas barrier layer / glossy printed layer / thermosoftening resin layer / LLDPE
(B6) Ny / glossy printed layer / gas barrier layer / thermosoftening resin layer / LLDPE

(Container with lid)
6 and 7 show an example of an embodiment of a container with a lid of the present invention. 6 is a top view, and FIG. 7 is a cross-sectional view taken along the line IV-IV in FIG. A container 30 with a lid shown in FIGS. 6 and 7 includes a container body 32 in which a housing portion 31 is formed, and a lid body 33 joined to the container body 32 so as to seal the housing portion 31 of the container body 32. ing. In FIG. 6, the shape of the container body 32 is substantially rectangular, but is not particularly limited. The molding method of the container body 32 is not particularly limited, and may be, for example, a tray molded by injection molding or a container formed by deep drawing.
In addition, since the material of the container body 32 is to be joined to the lid 33, it is usually a thermoplastic resin such as PP or PET, and particularly in the case of a container with a lid for a microwave oven. From the viewpoint of heat resistance and the like, PP is preferably used.

  It is preferable that the lid 33 of the container 30 with lid is formed of the packaging material 1 of the present invention. According to such a lid 30, it is possible to produce a beautiful appearance due to metallic luster and to provide a lidded container that suppresses glare of reflected light under sunlight. FIG. 6 shows that the lid 33 is formed of the packaging material 1 having a laminated structure as shown in FIG. 2 so as to have the gloss printing layer 3a and the pattern printing layer 3b.

The lid 33 has an easy peel property as described in the description of the sealant layer 4 of the packaging material 1 from the viewpoint of making it easy to open the container 30 with the lid by peeling from the container body 32. It is preferable.
Specifically, the lid 33 and the container body 32 are joined by a joining line 35 of the flange portion 34 of the container body 32. For example, the joining line 35 may be formed by heat sealing between the lid 33 and the flange portion 34, or may be formed by a separate component such as an adhesive layer.

When the lidded container 30 is used for a microwave oven, when the pressure in the lidded container 30 is increased by steam generated by cooking such as food that is the contents contained in the container body 32, the lid is attached. It is preferable to provide an automatic steaming mechanism (third embodiment of the automatic steaming mechanism) that automatically escapes the steam in the container 30 to the outside and prevents the lidded container 30 from bursting.
For example, the flange portion 34 has a protruding portion 34a that protrudes toward the center of the container body 32, and along this protruding portion 34a, the joining line 35 also protrudes in a convex shape toward the center of the container. A line 35a is provided. By forming the joining line 35 in such a form, it becomes easy to peel from the location of the protruding line 35a in the joining line 35 as the pressure in the lidded container 30 increases due to heating, and the container body The 32 accommodating parts 31 and the exterior can be connected, and the vapor | steam in the container 30 with a lid | cover can be escaped outside.
In addition, in the container 30 with a lid shown in FIGS. 6 and 7, the protruding portions 34 a are formed on the opposing long sides of the flange portion 34, but the two protruding portions 34 a are not necessarily formed. May be.

  Moreover, as the lid 33 constituting the container 30 with the lid, the packaging material shown in FIG. 11 (a packaging material having a heat-softening resin layer between the plastic film and the sealant layer and in the vicinity of the edge portion). By using this, for the same reason as described in the second embodiment of the automatic steaming mechanism described above, steam can be released when heated in a microwave oven.

<Cover body>
The lid of the present invention is formed of the packaging material of the present invention described above.

It is preferable that the packaging material which comprises a cover body is set as the laminated structure in any one of (1)-(4) mentioned above.
When the lid is used for a microwave oven or a retort container, as the plastic film, a polyester film alone, a polyamide film alone such as nylon, a composite film containing at least one of polyester film and polyamide film may be used. preferable.
Further, when the lid is used for a microwave oven or a retort container, as the intermediate base material layer, a polyester film alone, a polyamide film alone such as nylon, a composite film containing at least one of polyester film and polyamide film, and It is preferable to use paper.
When the lid is used for a microwave oven or a retort container, it is preferable to use a film made of a resin having both heat resistance and easy peel properties as the sealant layer. Such a film varies depending on the type of container, but when the container is a propylene resin that is a general-purpose resin, it is preferable to use a film made of a resin in which PP and one or more selected from PE, polybutene, and polystyrene are mixed. . In addition, you may give an easy peel property only to the side (innermost layer in a packaging material) joined to the container main body of a sealant layer by making a sealant layer into a multilayer structure.

More specifically, it is preferable that the packaging material constituting the lid has a laminated structure of any one of the following (C1) to (C11). Note that “/” means the boundary of each layer. In (C1) to (C11), it is preferable that PET and Ny are stretched films.
(C1) PET / glossy printed layer / Ny / sealant layer with easy peel property (C2) PET / gas barrier layer / glossy printed layer / Ny / sealant layer with easy peel property (C3) PET / glossy printed layer / Gas barrier layer / Ny / sealant layer with easy peel property (C4) PET / gloss printed layer / PET / sealant layer with easy peel property (C5) PET / gas barrier layer / gloss printed layer / PET / easy peel property Sealant layer with (C6) PET / Glossy printed layer / Gas barrier layer / PET / Sealant layer with easy peel properties (C7) Ny / Glossy printed layer / Ny / Sealant layer with easy peel properties (C8) Ny / Gas barrier layer / glossy printing layer / Ny / sealant layer with easy peel properties (C9) Ny / glossy printing layer / gas burr Sealant layer comprising a layer / Ny / easy peel resistance (C10) Ny / gloss print layer / EVOH / easy peel sealant layer having a (C11) sealant layer with Ny / EVOH / gloss print layer / easy peel properties

  In addition, what is necessary is just to form the thermosoftening resin layer mentioned above in a part between a plastic film and a sealant layer, when employ | adopting the structure of 2nd embodiment of the automatic steaming mechanism mentioned above for the cover body.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this.

1. Production of packaging material [Example 1]
From the outer layer side, a packaging material laminated in the order of plastic film / deposition film / gas barrier coating film / glossy printing layer / white ground color printing layer / adhesive layer / intermediate base material layer / adhesive layer / sealant layer was obtained. . The configuration of each layer is as follows.
・ Plastic film: PET (thickness 12μm)
Gas barrier layer: A corona discharge treatment was performed on one surface of a plastic film, and then a silicon oxide vapor deposition film having a thickness of 10 nm was formed. Furthermore, after performing plasma treatment with a mixed gas of oxygen and argon, a coating liquid mainly composed of ethyl silicate and polyvinyl alcohol is applied with a gravure roll coater to form a gas barrier coating film having a dry film thickness of 300 nm. did.
Glossy printing layer: The following glossy printing layer gold ink 1 was gravure-printed and dried on the entire surface of the gas barrier layer to form a glossy printing layer having a dry film thickness of 3 μm.
-White ground color printing layer: Furthermore, the white pigment ink was gravure-printed and dried on the entire surface of the glossy printing layer to form a white ground color printing layer having a dry film thickness of 3 μm.
Intermediate substrate layer: Stretched Ny (thickness: 15 μm) was bonded to the surface of the white ground color printing layer by a dry laminating method using a polyurethane adhesive.
Sealant layer: CPP (single layer film of ethylene-propylene block copolymer, thickness 70 μm) was bonded to the surface of the intermediate base material layer by a dry laminating method using a polyurethane adhesive.

<Gold ink 1 for glossy printing layer>
・ 10 parts by weight of white pearl pigment (average particle size 15 μm)
-Colored pearl pigment 20 parts by mass (colored pearl pigment whose mica coating layer is ferric oxide, average particle size 15 μm)
-0.001 part by mass of carbon black-0.1 part by mass of inorganic fine particles (silica, average primary particle size: 20 nm)
・ 10 parts by weight of binder resin (polyurethane resin, melting point 140 ° C.)
-Solvent 1 60 parts by mass (mixed solvent of propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, isopropanol)

[Example 2]
A packaging material was obtained in the same manner as in Example 1 except that the gold ink 1 for glossy printing layer was changed to the following gold ink 2 for glossy printing layer.

<Gold ink 2 for glossy print layer>
・ 7 parts by weight of aluminum scale (non-leafing type metal scale produced by the method of (i) in the specification)
(Average length 4 μm, average thickness 0.04 μm, aspect ratio 100)
-Organic yellow pigment 3 parts by mass-Inorganic fine particles 2 parts by mass (silica, average primary particle size: 20 nm)
・ 20 parts by weight of binder resin (polyurethane resin, melting point 140 ° C.)
・ Solvent 1 70 parts by mass (mixed solvent of propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, isopropanol)
・ Solvent 2 (mineral spirit) 7 parts by mass

[Comparative Example 1]
A packaging material was obtained in the same manner as in Example 1 except that the gold ink 1 for glossy printing layer was changed to the following gold ink 3 for glossy printing layer.

<Gold ink 3 for glossy printing layer>
・ 7 parts by mass of aluminum scale (non-leafing type metal scale produced by the method (ii) in the specification)
(Average length 20 μm, average thickness 0.1 μm, aspect ratio 200)
-Organic yellow pigment 3 parts by mass-Inorganic fine particles 2 parts by mass (silica, average primary particle size: 20 nm)
・ 20 parts by weight of binder resin (polyurethane resin, melting point 140 ° C.)
・ Solvent 1 70 parts by mass (mixed solvent of propylene glycol monomethyl ether, normal propyl acetate, ethyl acetate, isopropanol)
・ Solvent 2 (mineral spirit) 7 parts by mass

2. Preparation of sample 2-1. Sample A
A black plate is bonded to the CPP side surface of the packaging materials of Examples 1 and 2 and Comparative Example 1 via a transparent adhesive layer, the packaging materials of Examples 1 and 2 and Comparative Example 1, the transparent adhesive layer, and Sample A in which black plates were laminated was produced. Sample A used was CPP, a transparent adhesive, and a black plate having a refractive index difference of 0.05 or less.

2-2. Sample B
A pouch having the structure of FIG. 5 was prepared and sealed using the packaging materials of Examples 1 and 2 and Comparative Example 1. The produced pouch was retorted (high retort treatment) at 135 ° C. for 30 minutes using a batch hot water spray sterilization tester manufactured by Nisaka Manufacturing Co., Ltd. The specifications of the testing machine are shown below. Moreover, a packaging material is cut out from the retorted pouch, a black plate is bonded to the CPP side surface of the cut packaging material via a transparent adhesive layer, and the retorted treatment of Examples 1-2 and Comparative Example 1 Sample B was prepared by laminating a packaging material, a transparent adhesive layer, and a black plate. Sample B used had a difference in refractive index of CPP, transparent adhesive, and black plate within 0.05.

<Specifications of hot water spray sterilization tester>
・ Processing amount: 20kg
・ Maximum operating pressure: 0.5 MPa
・ Maximum operating temperature: 140 ℃
・ Wetted parts material: SUS316
・ Sterilization tank dimensions: Inner diameter = 600mm, straight body = 735mm
・ Effective liquid volume: 20L
・ Heating method: Hot water spray heating ・ Cooling method: Spray cooling ・ Pressure control: Constant pressure, aeration method ・ Processing mechanism: Static type ・ Temperature raising capacity: 20-130 ℃ 11 minutes ・ In-tank temperature distribution: Within ± 0.5 ℃・ Device dimensions: W1,330 × L2,130 × H1,800mm
・ Apparatus weight: 1,600kg
・ Utility: Steam = 150kg / h, Cooling water = 360L / time (2m ³ / h), Facility power = 5.4kW

3. Measurement Set the sample prepared in the above 2-1 and 2-2 to a variable angle photometer (product number GP-200, manufactured by Murakami Color Research Laboratory Co., Ltd., with a tilt angle within the luminous flux of 0.5 degrees or less). Visible light inclined by 45 degrees from the normal direction is incident on the surface of the sample packaging material side, the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the range of ± 15.0 degrees around the reference angle The intensity of reflected light was measured every 0.1 degree. At the time of measurement, the scale of the light receiving diaphragm was set to “4”, and the scale of the beam stop was set to “3”.
Based on the obtained reflection intensity for each angle, d ₁ (degrees), | (d ₁ −d ₂ ) / d ₁ | × 100 in equation (1), | (d ₃ −d _{4 in} equation (2) ) / D ₃ | × 100 was calculated.

4). Evaluation 4-1. Appearance by metallic luster Under the illumination of an indoor fluorescent lamp, the packaging materials of Examples 1 and 2 and Comparative Example 1 (packaging material before high retort treatment) were observed from the plastic film side, and the appearance by metallic luster was evaluated. Twenty subjects evaluated the average score by assigning 3 points for those with good metallic luster, 2 points for inferior aesthetics, and 1 point for inferior metallic luster. The results are shown in Table 1.
<Evaluation criteria>
A: Average score is 2.5 or more B: Average score is 1.5 or more and less than 2.5 C: Average score is less than 1.5

4-2. Change in metallic luster (change in appearance)
Under the illumination of an indoor fluorescent lamp, the sample A and the sample B were observed from the plastic film side, and the difference in metallic luster between the two samples was evaluated. 20 subjects were evaluated with 3 points that did not feel the difference in metallic luster between the two samples, 2 points that could not be said either, and 1 point that felt the difference in metallic luster between the two samples, The average score was calculated. The results are shown in Table 1.
<Evaluation criteria>
A: Average score is 2.5 or more B: Average score is 1.5 or more and less than 2.5 C: Average score is less than 1.5

From the results shown in Table 1, by selecting a packaging material that satisfies the formula (1), it is possible to generate an aesthetic appearance due to metallic luster without using a metal layer, and it is possible to suppress changes in appearance during the distribution process. It can be confirmed that the packaging material can be provided.
In the packaging material of Comparative Example 1, since the wrinkles on the surface of the metal scale were restored by high retort processing, the reflection intensity diffused to a wide angle decreased, and the reflection intensity near the regular reflection direction increased. ).

DESCRIPTION OF SYMBOLS 1 Packaging material 2 Plastic film 3a Glossy printed layer 3b Picture printed layer 3c Black ground color printed layer 3d White ground color printed layer 4 Sealant layer 5 Intermediate base material layer 6 Adhesive layer 7 Thermosoftening resin layer 10 Packaging container 11 trunk | drum 12 bottom 13 main surface sheet 14 side edge 15 lower edge 16 bottom sheet 17 accommodation space 18 upper edge 19 opening 20 automatic steaming mechanism 21 first unsealed area 22 opening 23 second unsealed area 24 notch 25 heat seal section 25a tension Outlet part 30 Container with lid 31 Container part 32 Container body 33 Lid body 34 Flange part 35 Joining line 100 Sample

Claims (6)

At least a plastic film, a printing layer, and a sealant layer, a packaging material sorting method having a configuration in which the outer layer side is laminated in this order,
In the case of having a glossy print layer containing a glitter pigment as the print layer, an angle d ₁ indicating an intensity of ½ of the intensity of reflected light in the regular reflection direction of the packaging material measured under measurement condition 1 below, the angle indicating the half of the intensity of the intensity of the reflected light of the specular reflection direction of the packaging material were measured under the measurement conditions 2 described below upon a d _2, and pass line satisfies the following formula (1) How to sort packaging materials.
| (D ₁ −d ₂ ) / d ₁ | × 100 ≦ 8.0% (1)
<Measurement condition 1>
A black plate is bonded to the surface of the packaging material on the sealant layer side through a transparent adhesive layer, and sample A in which the packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined 45 degrees from the normal direction of the sample A is incident on the surface of the sample A on the packaging material side, and the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the reference angle is the center. In the range of ± 15.0 degrees, the intensity of reflected light is measured every 0.1 degrees.
<Measurement condition 2>
A retort-treated packaging material obtained by retorting the packaging material with a batch type hot water shower type retort apparatus at 135 ° C. for 30 minutes is obtained. A black plate is bonded to the surface of the retort-processed packaging material on the sealant layer side through a transparent adhesive layer, and sample B in which the retort-processed packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined by 45 degrees from the normal direction of the sample B is incident on the surface of the sample B on the retort-treated packaging material side, and the regular reflection direction of the incident light is set to 0 degree as a reference angle, and the reference angle is set. In the range of ± 15.0 degrees as the center, the intensity of the reflected light is measured every 0.1 degrees.   The method for selecting a packaging material according to claim 1, wherein the glitter pigment is a metal scale or a pearl pigment.   The packaging material sorting method according to claim 1 or 2, wherein the packaging material is a microwave packaging material. A packaging material having a configuration in which at least a plastic film, a printing layer, and a sealant layer are laminated in this order from the outer layer side, and has a glossy printing layer containing a bright pigment as the printing layer, and the following measurement An angle indicating ½ of the reflection intensity in the regular reflection direction of the packaging material measured in condition 1 is d ₁ , and 1 of the intensity of reflected light in the regular reflection direction of the packaging material measured in measurement condition 2 below. / the angle indicating the second intensity upon the d _2, packaging material satisfying the following formula (1).
| (D ₁ −d ₂ ) / d ₁ | × 100 ≦ 8.0% (1)
<Measurement condition 1>
A black plate is bonded to the surface of the packaging material on the sealant layer side through a transparent adhesive layer, and sample A in which the packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined 45 degrees from the normal direction of the sample A is incident on the surface of the sample A on the packaging material side, and the regular reflection direction of the incident light is set to 0 degree of the reference angle, and the reference angle is the center. In the range of ± 15.0 degrees, the intensity of reflected light is measured every 0.1 degrees.
<Measurement condition 2>
A retort-treated packaging material obtained by retorting the packaging material with a batch type hot water shower type retort apparatus at 135 ° C. for 30 minutes is obtained. A black plate is bonded to the surface of the retort-processed packaging material on the sealant layer side through a transparent adhesive layer, and sample B in which the retort-processed packaging material, the transparent adhesive layer, and the black plate are laminated is prepared. Visible light inclined by 45 degrees from the normal direction of the sample B is incident on the surface of the sample B on the retort-treated packaging material side, and the regular reflection direction of incident light is set to 0 degree as a reference angle, and the reference angle is In the range of ± 15.0 degrees as the center, the intensity of the reflected light is measured every 0.1 degrees.   A retort container, at least a part of which is formed of the packaging material according to claim 4.   The retort container according to claim 5, which is for a microwave oven.