JP2019131226A - Packaging material for microwave oven and packaging box - Google Patents

Abstract

To provide a paper-made packaging material for a microwave oven which can produce a beautiful appearance by metallic luster and can suppress heat generation in using it in a microwave oven, and a packaging box for a microwave oven using the same.SOLUTION: A packaging material for a microwave oven is configured by forming a luminous printed layer 3 on an outer layer side on a paper base material 2. The luminous printed layer 3 includes a pearl pigment and a metal scale. The content of the pearl pigment is 40-90 pts.mass based on 100 pts.mass of the total of the pearl pigment and the metal scale. A packaging box for a microwave oven is formed of the packaging material for a microwave oven.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a paper microwave packaging material and a microwave packaging box using the same.

The packaging material may be decorated with metallic luster from the viewpoint of producing a sense of quality and luxury of a packaged object and generating an aesthetic appearance. As such a decoration means, for example, a metal layer made of a metal vapor deposition film or a metal foil is generally formed.
However, when such a packaging material using a metal layer is used in a microwave oven, the microwave in the microwave oven is reflected on the surface of the metal layer, resulting in a spark, resulting in a failure or accident of the microwave oven. There is sex.

  In response to this, for example, in Patent Document 1, a package formed by providing a plastic sheet with a gloss layer made of an ink containing a high-intensity aluminum paste having a predetermined concentration has a high aesthetic appearance and is heated in a microwave oven. It is described that it is difficult to deteriorate even if it is.

JP 2017-81589 A

  However, the gloss layer made of a high-brightness aluminum paste as described in Patent Document 1 has a problem that it generates heat when heated in a microwave oven, although it has good metallic gloss. When the surface of such a glossy layer is touched with bare hands, there is a risk of burns due to high temperatures. Also, depending on the heating conditions in the microwave oven, there may be a hole in the part where the high-intensity aluminum paste is used, and it is difficult to say that the deterioration is sufficiently suppressed, and when heating in the microwave oven is used It could not be said that safety was sufficient.

  The present invention has been made in order to solve the above-described problems, and is a paper-made microwave oven capable of producing an aesthetic appearance due to metallic luster and suppressing heat generation during use in a microwave oven. It aims at providing the packaging material for microwave ovens, and the packaging box for microwave ovens using the same.

  The present invention is based on the finding that by using a pearl pigment together in the glossy layer of the packaging material, heat generation during use in a microwave oven is suppressed while producing a beautiful appearance due to metallic luster. .

That is, the present invention provides the following [1] and [2].
[1] It has a configuration in which a glitter printing layer is formed on the outer layer side on a paper substrate, the glitter printing layer includes a pearl pigment and a metal scale, and a total of 100 masses of the pearl pigment and the metal scale. The packaging material for microwave ovens whose content of the said pearl pigment with respect to a part is 40-90 mass parts.
[2] A microwave oven packaging box, which is a box formed of the microwave oven packaging material according to [1].

  ADVANTAGE OF THE INVENTION According to this invention, the packaging material for paper microwave ovens which can produce the beauty | look by metallic luster and can suppress the heat_generation | fever at the time of use with a microwave oven can be provided. Moreover, the packaging box for microwave ovens which has the high-class feeling by metallic luster can be provided using the said packaging material for microwave ovens.

It is a schematic sectional drawing which shows an example of the laminated structure of the packaging material for microwave ovens of this invention. It is a schematic perspective view which shows the one aspect | mode of the packaging box for microwave ovens of this invention.

  Hereinafter, the microwave oven packaging material of the present invention and the microwave oven packaging box using the same will be described in detail with reference to the drawings. In addition, the notation of the numerical range of “AA to BB” in the present specification means “AA or more and BB or less”.

[Packaging materials for microwave ovens]
In FIG. 1, the outline of the laminated structure of the thickness direction in the one aspect | mode of the packaging material for microwave ovens of this invention is shown. In FIG. 1, the upper side is the outer layer side (front side), and the lower side is the inner layer side (back side). As shown in FIG. 1, a packaging material 1 for a microwave oven according to the present invention has a glitter printing layer 3 formed on a paper substrate 2. And the glitter printing layer 3 contains a pearl pigment and a metal scale, The content of the said pearl pigment with respect to a total of 100 mass parts of the said pearl pigment and the said metal scale is 40-90 mass parts, It is characterized by the above-mentioned. .
According to the packaging material provided with such a glittering printed layer 3, heat generation during use in a microwave oven can be suppressed while producing an appearance with metallic luster.

In addition, in the packaging material 1 for microwave ovens shown in FIG. 1, the glitter printing layer 3 and the pattern printing layer 4 are formed in parallel on the outer layer side surface of the paper substrate 2, and further, the glitter printing layer. A top coat layer 5 is formed on the outer layer side surfaces of both 3 and the pattern printing layer 4. The packaging material for microwave ovens of this invention should just be equipped with the glitter printing layer 3 on the paper base material 2, and is not limited to the aspect shown in FIG.
Hereinafter, each of these layer configurations will be described.

(Paper substrate)
The paper base material 2 used for the microwave packaging material 1 is not particularly limited as long as it has a desired shapeability, bending resistance, rigidity, waist, strength, and the like according to the packaging purpose. . For example, it is a main strength material, and various types of paper such as strong sized bleached or unbleached paper, or pure white roll paper, kraft paper, paperboard, processed paper, and milk base paper can be used. When forming a packaging box using the packaging material 1 for microwave ovens, a paperboard is normally used from viewpoints of workability, use in a microwave oven, etc. Examples of the type of paperboard include those usually used as paperboard paperboard such as white paperboard, yellow paperboard, chipball, and color paperboard. Among these, white paperboard such as Manila cardboard and coated cardboard is often used.

The thickness of the paper substrate 2 is preferably 110 to 860 μm, more preferably 260 to 640 μm, from the viewpoints of handleability and strength in printing and bending. The basis weight of the paper substrate, from the viewpoint of handleability and strength, and the like in the printing or bent like is preferably 80~600g / m ^2, more preferably from 230~550g / m ^2.
In addition, the thickness of the paper base material in this specification and each layer is taken of the photograph of the cross section which cut | disconnected the packaging material for microwave ovens in the orthogonal | vertical direction with respect to the paper surface, and the thickness of 20 places measured based on this cross-sectional photograph. It is a value obtained as an average value.

(Glitter printed layer)
The glitter print layer 3 is formed by printing on the paper substrate 2 with the glitter print layer ink. The ink for glittering printing layer is usually an ink composed mainly of a vehicle composed of a binder resin and a solvent, and further added with a pearl pigment, metal scale, and, if necessary, a colorant such as a dye or pigment. Is used. Examples of the printing method include gravure printing, offset printing, letterpress printing, silk screen printing, and the like. Of these, gravure printing is preferred.

The glitter print layer 3 may be formed on the entire surface of the region visible from the outer layer side of the microwave packaging material 1 or may be formed only on a part thereof. The glitter print layer 3 may form pictures such as pictures and characters (product names, product display, quality display, etc.), figures, symbols, patterns, patterns, and the like. Further, the glitter print layer 3 may be composed of one layer or may be composed of two or more layers.
The thickness of the glitter print layer 3 is preferably 0.5 to 10 μm, more preferably 0.8 to 8 μm, and further preferably 1 to 5 μm, from the viewpoint of obtaining sufficient metallic gloss. is there.
Note that the glitter print layer 3 may be formed by forming an anchor coat layer on the paper substrate 2 and in contact with the anchor coat layer from the viewpoint of improving adhesion to the paper substrate 2. The anchor coat layer may have a known configuration, and examples of the constituent material include polyethyleneimine and two-component curable polyurethane.

The glitter print layer 3 includes a pearl pigment and metal scales. By the pearl pigment and the metal scale, the glitter print layer 3 has a glitter property, and a metallic luster is imparted to the microwave packaging material 1.
The total content of the pearl pigment and the metal scale in the glitter print layer 3 is such that the glitter print layer 3 has a uniform metallic luster and the adhesion of the pearl pigment and the metal scale to the paper substrate 2. From a viewpoint, it is preferable that it is 20-50 mass% in the glittering printing layer 3, More preferably, it is 25-48 mass%, More preferably, it is 30-45 mass%.

The pearl pigment and metal scale contained in the glitter print layer 3 have a pearl pigment content of 40 to 90 parts by mass with respect to 100 parts by mass in total of the pearl pigment and the metal scale. When the content of the pearl pigment is more than 90 parts by mass, it is difficult to form the glitter print layer 3 having sufficient metal gloss. On the other hand, when the amount is less than 40 parts by mass, heat generation in the region where the glitter printing layer 3 of the microwave packaging material 1 is formed cannot be sufficiently suppressed during use in the microwave oven.
From the viewpoint of higher metallic gloss, the content of the pearl pigment is preferably 80 parts by mass or less. In addition, when used in a microwave oven, it is 65 parts by mass or more from the viewpoint of further suppressing heat generation in the region where the glitter printing layer 3 of the microwave packaging material 1 is formed and ensuring sufficient safety. It is preferable.

Examples of pearl pigments include 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 pearl pigment or a polarized pearl pigment.
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.

As the pearl pigment, from the viewpoint of obtaining a pearl coating color with higher brightness and giving a high-class feeling from any direction, at least one selected from a white pearl pigment and an interference pearl pigment, and a colored pearl pigment It is preferable that 1 or more types chosen from among these are included. 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 length is preferably 5 to 60 μm, more preferably 5 to 30 μm. In addition, the average length of a pearl pigment is calculated | required as an average value of the major axis of arbitrary 20 particles observed with the optical microscope.

Examples of the metal of the metal scale include metals and alloys such as aluminum, gold, silver, brass, titanium, chromium, nickel, nickel chromium, and stainless steel. Among these, aluminum is preferable from the viewpoints of versatility and availability.
For example, the metal scale is obtained by peeling a metal thin film formed by vacuum-depositing the metal or alloy on a plastic film from the plastic film, crushing and stirring the peeled metal thin film, or powder of the metal or alloy. And those obtained by spreading and / or pulverizing the powder with a medium stirring mill, ball mill, attritor or the like, and those having a resin-coated surface. it can.

From the viewpoint of uniform dispersibility in the glitter print layer 3, the metal scales preferably have an average length of 0.2 to 50 μm, more preferably 1 to 30 μm, and even more preferably 2 to 20 μm. . Further, from the viewpoint of obtaining handleability and high metallic gloss, the average thickness is preferably 0.01 to 5 μm, more preferably 0.02 to 3 μm, and still more preferably 0.03 to 1 μm. From the same viewpoint, the aspect ratio (average length / average thickness) of the metal scale is preferably 15 to 500, more preferably 20 to 450, and further preferably 25 to 400.
The average length and thickness of the metal scales are the lengths and thicknesses of the 20 metal scales using a laser interference type three-dimensional shape analyzer in a state where the metal scales are dispersed on a smooth substrate. Is obtained and obtained as an average value of these measured values. The length of one metal scale means the maximum diameter (length) when the metal scale is observed in a plane in an arbitrary axial direction. The thickness of one metal scale means the maximum thickness (length) of the metal scale in a direction (cross section) perpendicular to the axial direction. For example, when the X-axis direction of the processed image of the measurement result by the three-dimensional shape analyzer is an arbitrary axial direction (measurement direction), the maximum diameter of one metal scale obtained in the direction parallel to the X-axis is 1 The length of each piece of metal scale. Even if the length in a direction not parallel to the X axis is larger than the maximum diameter, the length is not regarded as the maximum diameter. As a laser interference type three-dimensional shape analysis apparatus, for example, a shape analysis laser microscope “VK-X series” manufactured by Keyence Corporation can be used.

Examples of the binder resin in the glitter print layer 3 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 copolymer, polystyrene resin, styrene-butadiene copolymer, vinylidene fluoride resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinyl butyral resin, polybutadiene resin, polyester resin, polyamide resin , Alkyd resins, epoxy resins, unsaturated polyester resins, thermosetting poly (meth) acrylic resins, melamine resins, urea resins, polyurethane resins, phenol resins, xylene resins, maleic resins, Nitrocellulose or ethyl Cellulose, cellulose resins such as acetyl butyl cellulose, ethyl oxy ethyl cellulose, rubber and cyclized rubber rubber resin chloride, petroleum resin, rosin, and natural resins such as casein, and the like. These may be used alone or in combination of two or more.
The content of the binder resin in the glittering printing layer 3 depends on the solid content other than the pearl pigment and the metal scale, but the adhesion of the pearl pigment and the metal scale to the paper substrate 2 and the printing efficiency, etc. From a viewpoint, it is preferable that it is 20-50 mass%, More preferably, it is 25-48 mass%, More preferably, it is preferable that it is 30-45 mass%, and is equivalent to the total content of a pearl pigment and a metal scale. Preferably there is.

Examples of the solvent used in the ink for the glitter printing layer include alcohol solvents such as methanol, ethanol, normal propanol, isopropanol, and propylene glycol monomethyl ether, ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, methyl acetate, Ester solvents such as ethyl acetate and normal propyl acetate, aliphatic hydrocarbon solvents such as normal hexane, normal heptane and normal octane, alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane and cycloheptane, toluene and xylene, etc. Aromatic solvents, mineral spirits and the like. These may be used alone or in combination of two or more. In addition, when there is a concern about the working environment at the time of printing and the influence on the package, it is particularly preferable not to include an aromatic solvent.
Further, for the glitter printing layer ink, for example, a color stabilizer, a filler, a stabilizer, a plasticizer, an antioxidant, a light stabilizer such as an ultraviolet absorber, a dispersant, a thickener, Arbitrary additives such as a desiccant, an anti-settling agent, a lubricant, an antistatic agent, and a crosslinking agent can be added. These additives may be inorganic compounds or organic compounds.

(Picture printing layer)
The pattern print layer 4 is a broad concept including, for example, characters (product name, product display, quality display, etc.), figures, photographs, symbols, patterns, patterns, solid prints, etc., and is distinguished from the glitter print layer 3. Printed layer. That is, the pattern printing layer 4 does not include a printing layer formed with the glitter printing layer ink. The pattern printing layer 4 may be composed of one layer or may be composed of two or more layers. The pattern printing layer 4 may be printed on the entire surface of the paper substrate 2 or may be partially printed. The pattern printing layer 4 can be formed by, for example, single color or multicolor printing using process colors, or can be formed by other special color printing or the like.

In the microwave packaging material 1 in FIG. 1, the pattern print layer 4 is formed so as to be arranged in parallel in the same plane as the glitter print layer 3, but the outer layer side (surface) of the glitter print layer 3 or You may form so that it may overlap with the inner layer side (back surface). However, at least a part of the glitter print layer 3 is formed so as to be visible from the outer layer side.
As a specific layer structure in the case where the glitter print layer 3 and the pattern print layer 4 are formed so as to overlap, for example, at least a part of the glitter print layer 3 / the pattern print layer 4 is in this order from the inner layer side. The pattern printing layer 4 / the glitter printing layer 3 and the pattern printing layer 4 / the glitter printing layer 3 / the pattern printing layer 4 can be formed in this order.
The thickness of the pattern print layer 4 is not particularly limited, but is usually preferably about 0.2 to 10 μm, more preferably 0.5 to 8 μm, and more preferably 0.7 to 5 μm. .

  The pattern printing layer 4 is usually formed by printing using a pattern printing layer forming ink in which a vehicle composed of a binder resin or a solvent is a main component and a coloring agent such as a dye or a pigment is added and mixed therewith. Examples of the printing method include gravure printing, offset printing, letterpress printing, silk screen printing, and the like. Of these, gravure printing is preferred.

  Examples of the colorant for the pattern printing layer 4 include general-purpose dyes and pigments (for example, inorganic pigments such as chrome lead, titanium yellow, petiole, cadmium red, ultramarine blue, cobalt blue; quinacridone red, isoindolinone yellow, phthalocyanine blue, etc. Organic pigments). In addition, as the black pigment, general-purpose black pigments such as carbon black and titanium black can be used, but a portion of the microwave packaging material 1 in which carbon black, titanium black, or the like is present due to microwave microwaves, Since there is a possibility of local overheating, care must be taken such as suppressing the amount of blending in the pattern print layer forming ink. Examples of other black pigments include organic pigments such as perylene black and azomethine azo pigments; iron oxides such as magnetite type triiron tetroxide; and inorganic pigments such as composite oxides such as copper, chromium and zinc.

  As the binder resin, the solvent, and the additive in the pattern printing layer forming ink, those similar to those used in the above-described glittering printing layer forming ink can be used.

In addition, as one aspect of the pattern printing layer, a black dye or pigment is provided on the surface of the glittering printing layer 3 that is in contact with the inner layer side from the viewpoint of increasing the depth of the metallic luster due to the pearl pigment of the glittering printing layer 3 or the solid feeling. It is also preferable that a black ground color layer is formed by black solid printing using an ink having a colorant or the like as a colorant. The black ground color layer preferably has an L ^* value of L ^* a ^* b ^* color system of the 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 colorant is preferably a black pigment from the viewpoint of developing a stable black color as a background color. The content of the black pigment is preferably 10 to 50% by mass, more preferably 15 to 45% by mass in the black background color layer, from the viewpoint of a stable color development as a background color and a printed film strength balance. More preferably, it is 20 to 40% by mass.

  As the black pigment, a general-purpose black pigment can be used in the same manner as described above, but attention should be paid to the content of the general-purpose black pigment in the black ground color layer from the viewpoint of overheating when used in a microwave oven. . Examples of other black pigments are the same as described above.

(Topcoat layer)
In the packaging material 1 for a microwave oven shown in FIG. 1, a top coat layer 5 is formed on the outer layer side surfaces of both the glitter print layer 3 and the pattern print layer 4. The topcoat layer 5 may be formed on the entire surface of the paper substrate 2 or may be formed on a part thereof. The top coat layer 5 is light transmissive.
As described above, the outermost surface of the packaging material for microwave oven 1 has surface protection for preventing scratches and dirt on the surface of the glitter print layer 3 (and the pattern print layer 4), and the glitter print layer 3 ( In addition, the top coat layer 5 is preferably formed from the standpoint of imparting a glossy feeling or a matte feeling to the decoration by the pattern printing layer 4) and enhancing a sense of quality.
The topcoat layer 5 can be formed with a known topcoat agent (overcoat agent). Examples of the topcoat agent include OP varnish (gloss varnish) that gives glossiness, matte OP varnish for matting, and the like, and can be selected and used according to each purpose. Examples of the printing method include gravure printing, offset printing, letterpress printing, flexographic printing, silk screen printing, and the like. Of these, gravure printing is preferred.
The thickness of the top coat layer 5 is preferably about 0.2 to 10 μm, more preferably 0.5 to 8 μm, and still more preferably 0.7 to 5 μm.

[Packaging box for microwave oven]
The microwave oven packaging box of the present invention is a box formed using the microwave oven packaging material. The said microwave oven packaging material can be used suitably as a forming material of the microwave oven packaging box which accommodates contents, such as foodstuffs heated by a microwave oven. By forming the microwave oven packaging box with the microwave oven packaging material, it is possible to produce a high-class feeling of the contents of the microwave oven packaging box.
The shape of the microwave packaging box is not particularly limited, and examples thereof include a rectangular parallelepiped shape, a cylindrical shape, and a cone shape, and can be various shapes suitable for heating the contents. .

In the microwave packaging box, the location having the glitter print layer is appropriately determined according to the desired decorative effect, and is not particularly limited, but particularly when placed in the microwave oven The box which has the glittering printing layer of the packaging material for microwave ovens which comprises this box in the at least side part of a box can be provided suitably.
When used in a microwave oven, the microwave packaging box is usually taken out from the microwave oven after being heated, by hand holding the side periphery of the box placed on the table surface in the microwave oven. For this reason, it is preferable that the side periphery of the box is not hot even if it is touched by hand. According to the packaging material for a microwave oven of the present invention, heat generation is suppressed while imparting metallic luster to the side peripheral portion of a box that is highly necessary to be touched by hand after heating the microwave oven, with a metallic gloss by the glitter printing layer. The decorative effect of the packaging box for microwave ovens and the safety during handling can be achieved at the same time.

The packaging box for microwave ovens of the present invention can be suitably used as, for example, an exterior box of a pouch filled with contents for performing microwave oven heating.
The microwave oven packaging box is specifically a pouch exterior box filled with various foods to be cooked in a microwave oven (e.g., retort food or frozen food), with the pouch still being housed, It can be suitably used when the outer box is heated by a microwave oven. In this case, the pouch is preferably provided with a steam release means forming portion that opens due to the internal vapor pressure increased by microwave heating, and the microwave packaging box is an exterior box that houses the pouch. Is preferably formed with an opening break line and a crease line for deformation into an opened state that holds the vapor escape means forming portion at a position higher than the contents. For example, it is preferably configured so that it can be placed in a microwave oven in a state opened in a manner as shown in FIG.
The microwave oven packaging box of the present invention is configured in such a manner, so that heat generation of the outer box can be suppressed during heating of the microwave oven, and filling accompanying pressurization with steam in the pouch Leakage of goods, rupture of the pouch, and the like are prevented, so that food cooked in the pouch can be safely cooked with a microwave oven.

  The microwave packaging box 10 shown in FIG. 2 is an exterior box that accommodates the pouch 20 and has a rectangular parallelepiped shape in an unopened state. FIG. 2 shows a form when the container is opened and placed in a microwave oven. First, the microwave oven packaging box 10 in which the pouch 20 is accommodated passes through the front panel 11 from the one side panel 12 to the other side panel 12 facing the one side panel 12 and is unsealed. Open along. And the upper part 10a of the box containing the top panel 14 is turned back at the crease line 17 provided on the back panel 13 (see the broken line arrow in the figure), and the side which is the boundary line between the front panel 11 and the top panel 14 L1 and the side L2 which is the boundary line between the back panel 13 and the bottom panel 15 are placed so as to contact the table surface in the microwave oven. If the microwave packaging box 10 can be placed in the microwave oven while maintaining the deformed unsealed state, the vapor escape means forming portion 21 provided on the upper portion of the pouch 20 can be placed in the pouch 20. It can be held at a higher position than the contents.

The pouch 20 is usually made of a multilayer plastic film having an excellent gas barrier property and having a heat seal layer on the inner surface, and the periphery is heat sealed and formed in a pouch shape. The pouch 20 has a steam escape means forming portion 21 at a position adjacent to the vicinity of the upper peripheral edge of the side where heat sealing is performed. The steam escape means forming portion 21 is a portion where stress accompanying the increase in internal pressure is concentrated when the pressure in the pouch 20 is increased by heating inside the side edge, and the stress concentration portion 21a is heat-sealed. And has a vent hole 21b in a portion surrounded by the stress concentration portion 21a. When the pressure in the pouch 20 rises due to microwave heating, the heat seal of the stress concentration portion 21a is peeled off, and the vapor in the pouch 20 can be discharged from the vent 21b. Thereby, rupture of the pouch 20 can be prevented, and the vapor escape means forming portion 21 is held at a position higher than the contents in the pouch 20, thereby leaking or scattering the contents of the pouch 20. It is possible to prevent contamination of the microwave oven.
In addition, the vapor | steam escape means formation part 21 of the pouch 20 is not limited to such a form, For example, Unexamined-Japanese-Patent No. 2015-120550, Unexamined-Japanese-Patent No. 2006-74457, Unexamined-Japanese-Patent No. 2006-74458 It is also possible to adopt a form as described in the above.

  The shape of the blank of the microwave packaging box 10 is not particularly limited, and the forms and positions of the unsealed line 16 and the crease line 17 are not limited to the mode shown in FIG. For example, it can also be set as the form described in Unexamined-Japanese-Patent No. 2006-44695, Unexamined-Japanese-Patent No. 2006-44695, Unexamined-Japanese-Patent No. 2012-201375, Unexamined-Japanese-Patent No. 2012-201376.

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

[Production of packaging materials for microwave ovens]
Example 1
The microwave packaging material 1 of the aspect shown in FIG. 1 was produced as follows.
A glossy printed layer having a thickness of 1.3 μm by gravure printing on a part of the surface of a paper substrate (coated cardboard having a thickness of 400 μm) using the glitter (gold) printing layer ink (1) having the following composition. Formed. In addition, a pattern printing layer having a thickness of 1.6 μm is formed by gravure printing at a location other than the location where the glitter printing layer on the outer layer side surface of the paper substrate is formed, by gravure printing. Formed.
Next, a 1.6 μm-thick topcoat layer was formed by gravure printing using OP varnish having the following composition on the surface of the glitter print layer and the pattern print layer on the paper substrate.

The composition of each ink is shown below.
<Ink for glittering (golden) printed layer (1)>
-Glitter component (1a): White pearl pigment ("Iriodin (registered trademark) 102" manufactured by Merck Performance Materials Co., Ltd.) 10 parts by mass-Glitter component (2): Aluminum paste (aluminum scale (content 60 mass%) )) Dispersed in a paste with a solvent (such as normal propyl acetate)) 5 parts by mass (3 parts by mass as aluminum scale)
Colorant (organic pigment (yellow, blue, red, black)) 5 parts by mass Binder resin (main component: nitrocellulose) 13 parts by mass Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 Part by mass / additive for aluminum (mixture of alcohol and oxalic acid) 3 parts by mass / solvent (mixed solvent of ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, methanol, and propylene glycol monomethyl ether) 67 parts by mass <pattern printing layer Ink>
Organic pigment (red) 10 parts by mass Binder resin (main component: nitrocellulose) 10 parts by mass Solvent (mixed solvent of ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, methanol, and propylene glycol monomethyl ether) 70 parts by mass Department <OP Varnish>
An ink composition obtained by dispersing an acrylic thermosetting resin composition in an aqueous solvent (a mixed solvent of water and isopropanol in a mass ratio of 3: 7).

(Examples 2 to 5, Comparative Examples 3 and 4)
In Example 1, the blending amount of the white pearl pigment and the aluminum paste in the glittering (golden) printing layer ink (1) was changed to the amount shown in Table 1 below, and otherwise the same as in Example 1, A packaging material for a microwave oven was produced. In Table 1, along with the description of the blending amount of the aluminum paste, the blending amount as the aluminum scale is shown in parentheses (the same applies hereinafter).

(Example 6)
Brightness (gold) prepared in Example 1 by changing the white pearl pigment of the glitter component (1a) in the glitter (gold) printing layer ink (1) to the interference pearl pigment (1b) shown below. A packaging material for a microwave oven was prepared in the same manner as in Example 1 except that the printing layer ink (2) was used.
<Ink for glitter (golden) printing layer (2)>
-Glitter component (1b): interference pearl pigment ("Iriodin (registered trademark) 201" manufactured by Merck Performance Materials Co., Ltd.) 10 parts by mass-Glitter component (2): aluminum paste (for glitter (golden) printed layer) Same as that used in ink (1)) 5 parts by mass (3 parts by mass as aluminum scale)
Colorant (organic pigment (yellow, blue, red, black)) 5 parts by mass Binder resin (main component: nitrocellulose) 13 parts by mass Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 Part by mass / additive for aluminum (mixture of alcohol and oxalic acid) 3 parts by mass / solvent (mixed solvent of ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, methanol, and propylene glycol monomethyl ether) 67 parts by mass

(Example 7)
Brightness (gold) prepared in Example 1 by changing the white pearl pigment of the glitter component (1a) in the glitter (gold) printed layer ink (1) to the colored pearl pigment (1c) shown below. A packaging material for a microwave oven was produced in the same manner as in Example 1 except that the printing layer ink (3) was used.
<Ink for glitter (gold) printing layer (3)>
-Glitter component (1c): Colored pearl pigment ("Iriodin (registered trademark) 302" manufactured by Merck Performance Materials Co., Ltd.) 10 parts by mass-Glitter component (2): Aluminum paste (for glitter (golden) printing layer Same as that used in ink (1)) 5 parts by mass (3 parts by mass as aluminum scale)
Colorant (organic pigment (yellow, blue, red, black)) 5 parts by mass Binder resin (main component: nitrocellulose) 13 parts by mass Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 Part by mass / additive for aluminum (mixture of alcohol and oxalic acid) 3 parts by mass / solvent (mixed solvent of ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, methanol, and propylene glycol monomethyl ether) 67 parts by mass

(Examples 8 and 9)
In Example 7, the amount of the white pearl pigment and the aluminum paste in the glittering (gold) printing layer ink (3) was changed to the amount shown in Table 1 below, and otherwise the same as in Example 7, A packaging material for a microwave oven was produced.

(Comparative Example 1)
In Example 1, only the aluminum paste of the glitter component (2) is used as the glitter component in the glitter (gold) printing layer ink (1) without using the white pearl pigment of the glitter component (1a). Using the glitter (gold) printed layer ink (4) thus prepared, a packaging material for a microwave oven was produced in the same manner as in Example 1.
<Ink for glitter (gold) printing layer (4)>
-Glitter component (2): Aluminum paste (same as that used in glitter (gold) printing layer ink (1)) 15 parts by mass (9 parts by mass as aluminum scale)
・ Colorant (organic pigment (yellow)) 4 parts by mass ・ Binder resin (main component: nitrocellulose) 13 parts by mass ・ Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 parts by mass ・ Addition for aluminum Agent (mixture of alcohol and oxalic acid) 3 parts by mass / solvent (mixed solvent of ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, methanol, and propylene glycol monomethyl ether) 67 parts by mass

(Comparative Example 2)
In Example 1, only the white pearl pigment of the glitter component (1a) was used as the glitter component in the glitter (gold) printed layer ink (1) without using the aluminum paste of the glitter component (2). Using the glitter (golden) printed layer ink (5) prepared below, a microwave packaging material was produced in the same manner as in Example 1.
<Ink for glitter (golden) printing layer (5)>
-Glitter component (1a): White pearl pigment (same as that used in glitter (gold) printing layer ink (1)) 15 parts by mass-Colorant (Organic pigments (yellow, blue, red, black)) ) 5 parts by mass · Binder resin (main component: nitrocellulose) 13 parts by mass · Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 parts by mass · Solvent (ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, 67 parts by mass of a mixed solvent of methanol and propylene glycol monomethyl ether)

(Comparative Example 5)
In Comparative Example 2, only the interference pearl pigment of the glitter component (1b) was used as the glitter component in the glitter (gold) printed layer ink (1) without using the aluminum paste of the glitter component (2). A microwave oven packaging material was prepared in the same manner as in Example 6 except that the glossy (golden) printed layer ink (6) prepared in this manner was used.
<Ink for glittering (golden) printing layer (6)>
-Glitter component (1b): interference pearl pigment (same as that used in glitter (gold) printing layer ink (2)) 15 parts by mass-Colorant (organic pigment (yellow, blue, red, black) ) 5 parts by mass · Binder resin (main component: nitrocellulose) 13 parts by mass · Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 parts by mass · Solvent (ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, 67 parts by mass of a mixed solvent of methanol and propylene glycol monomethyl ether)

(Comparative Example 6)
In Example 7, only the colored pearl pigment of the glitter component (1c) was used as the glitter component in the glitter (gold) printed layer ink (3) without using the aluminum paste of the glitter component (3). A microwave packaging material was prepared in the same manner as in Example 7 except that the glittering (golden) printing layer ink (7) prepared below was used.
<Ink for glittering (gold) printing layer (7)>
-Glitter component (1c): colored pearl pigment (same as that used in glitter (gold) printing layer ink (3)) 15 parts by mass-Colorant (organic pigment (yellow, blue, red, black) ) 5 parts by mass · Binder resin (main component: nitrocellulose) 13 parts by mass · Anti-settling agent (normal mass solution of fatty acid amide 2% by mass) 10 parts by mass · Solvent (ethyl acetate, methyl ethyl ketone, normal propyl acetate, isopropanol, 67 parts by mass of a mixed solvent of methanol and propylene glycol monomethyl ether)

[Illumination evaluation]
An evaluation test using a test monitor of 20 people was performed on the glitter of each microwave packaging material produced in the above Examples and Comparative Examples.
The test was carried out by visually observing from the outer layer side while tilting the packaging material in various directions under a fluorescent lamp in a room where outdoor light was shielded, and the presence or absence of aesthetics due to glitter (metallic luster) was evaluated.
The following criteria (1) to (4) were scored with reference to Comparative Example 1 in which the glitter component of the glitter print layer was only aluminum paste.
(1) The metallic luster is equivalent to the reference standard, and the degree of appearance is higher than the following (2). +2 points (2) Although the metallic luster is inferior to the reference standard, the beautiful appearance due to glitter is sufficiently produced. Yes +1 point (3) The metallic luster is inferior to the reference standard, and it cannot be said about the aesthetics due to the glitter. 0 point (4) Depending on the direction of observation, there is no metallic luster that produces aesthetics, and the glitter. The aesthetics by is not sufficient. -1 point The average value of the scoring results of 20 test monitors was calculated and evaluated as follows. The evaluation results are shown in Table 1 below.
<Evaluation rank>
S: Reference standard AA: Average score + 1.5 points or more A: Average score +1 point or more and less than 1.5 points B: Average score 0 points or more and less than +1 point C: Average score less than 0 points

[Exothermic evaluation]
About the exothermic property at the time of use with the microwave oven of each microwave packaging material produced by the said Example and comparative example, the evaluation test by a test monitor of 20 persons was done.
In the test, first, the microwave packaging material was cut into a 10 cm × 3 cm rectangle so as to include the glitter print layer and the pattern print layer when viewed from the outer layer side, and a test piece was collected. The test piece was placed on a table in a microwave oven with an output of 500 W so that the outer layer side of the test piece was the upper surface. After operating the microwave oven for 1 minute, the heat felt when the outer surface of the test piece was touched with bare hands was scored according to the following criteria (1) to (4), and the brightness of the packaging material for microwave ovens The print layer was evaluated for heat generation.
(1) Not hot at all +2 points (2) The area of the glitter print layer was hotter than the area of the pattern print layer, but it was hot enough to touch +1 point (3) The glitter print layer The area is hotter than the pattern printed layer, and after a while it was hot and released 0 points (4) It was too hot and immediately released hands -1 point The average value was calculated and evaluated as follows. The evaluation results are shown in Table 1 below.
<Evaluation rank>
A: Average point + 1 point or more B: Average point 0 point or more and less than +1 point C: Average point less than 0 point

As can be seen from the evaluation results in Table 1, the glittering printed layer containing the pearl pigment and the aluminum scale in a predetermined ratio can give a beautiful appearance due to metallic luster and suppress heat generation during use in a microwave oven. It was recognized that it could be.
In addition, when Examples 1-5 were compared, and when Examples 7-9 were compared, metal glossiness tended to increase as the content ratio of aluminum scales increased, but the content ratio of aluminum scales When there is little (Examples 1-3 and 7), it can be said that the heat_generation | fever at the time of use with a microwave oven is suppressed more, and it is more excellent in safety.

DESCRIPTION OF SYMBOLS 1 Packaging material for microwave ovens 2 Paper base material 3 Bright printing layer 4 Picture printing layer 5 Topcoat layer 10 Packaging box for microwave oven 11 Front panel 12 Side panel 13 Rear panel 14 Top panel 15 Bottom panel 16 Unsealed line 17 Crease line 20 Pouch 21 Steam escape means forming part

Claims (7)

It has a configuration in which a glitter printing layer is formed on the outer layer side on a paper substrate,
The packaging material for microwave ovens in which the said glittering printing layer contains a pearl pigment and a metal scale, and content of the said pearl pigment with respect to a total of 100 mass parts of the said pearl pigment and the said metal scale is 40-90 mass parts.   2. The microwave oven packaging material according to claim 1, wherein the glitter print layer has a content of the pearl pigment of 65 to 80 parts by mass with respect to a total of 100 parts by mass of the pearl pigment and the metal scale.   The packaging material for microwave ovens of Claim 1 or 2 whose sum total content of the said pearl pigment and the said metal scale is 20-50 mass% in the said glitter printing layer.   The packaging box for microwave ovens which is a box formed with the packaging material for microwave ovens of any one of Claims 1-3.   The packaging box for microwave ovens of Claim 4 which has the said glitter printing layer in the at least side part of this box when the said box is mounted in a microwave oven.   The packaging box for microwave ovens of Claim 4 or 5 which is an exterior box of a pouch. The pouch is filled with contents, and includes a steam release means forming portion that is opened by an internal vapor pressure that has been raised by microwave heating,
The unsealed cut line and crease line for deforming the outer packaging box that houses the pouch into an opened state that holds the vapor escape means forming portion at a position higher than the contents are formed. Packaging box for microwave oven.