JP6531057B2 - Laminated foam board, folding box, and peripheral side frame for folding box - Google Patents

Description

  The present invention relates to a laminated foam board in which a covering sheet is laminated on a polystyrene resin foam board, a folded box formed using the laminated foam board, and a peripheral side frame for the folded box.

Conventionally, after extruding and foaming a polystyrene-based resin composition from a circular die to form a cylindrical foam, the inside of the foam is not cooled down and pinched by pinch rolls to thermally fuse the inner surfaces to one another. It is practiced to form a base resin foam board.
Since this kind of polystyrene resin foam board is lightweight and excellent in strength, it is widely used, for example, as a peripheral side frame of containers such as mounts for display panels and folding boxes (see Patent Document 1 below) .

Such a polystyrene resin foam plate is generally white and has a beautiful appearance, but large bubbles are formed in a position close to the surface layer portion to be recognized as a dark point, or the cell diameter fluctuates in the surface direction and white. In some cases, unevenness may occur.
From such a thing, the laminated foam board which laminated | stacked the covering sheet for covering the surface of a polystyrene resin foam board on a polystyrene resin foam board is utilized for the above applications.

  This kind of laminated foam board can not only be a thing with no unevenness in whiteness using a white covering sheet, but various appearances are given by a covering sheet with a chromatic color or a covering sheet subjected to a design by printing etc. obtain.

JP, 2011-202006, A

As described above, the laminated foam plate can reflect the appearance of the covering sheet.
As such a covering sheet, use is made of a laminated sheet obtained by laminating a paper-like sheet that is easy to color in white or chromatic color or print a design etc. and a resin film for protecting the paper-like sheet. This is considered to be advantageous for exerting the appearance according to the application to the laminated foam board for a long time and continuously.
However, in an environment where strong light is applied to the laminated foam board, the reflected light may cause part of the laminated foam board to become white and the texture of the covering sheet may not be sufficiently exhibited.

  This invention makes it a subject to solve the above problems, and it makes it a subject to suppress that expression of the feeling of a covering sheet is inhibited by catoptric light.

  The laminated foam board according to the present invention for solving the above-mentioned problems is a laminated foam board comprising a polystyrene resin foam board and a covering sheet laminated on one side or both sides of the polystyrene resin foam board, The covering sheet has a laminated structure, and the covering sheet includes a resin film layer provided on the most surface side and a paper sheet layer in contact with the resin film layer from the inside, and the surface of the resin film layer The glossiness of is 2 or more and 20 or less.

In the present invention, since the surface glossiness of the resin film layer provided on the most surface side of the covering sheet is 2 or more and 20 or less, the intensity of the reflected light is weaker than that of the conventional laminated foam plate.
That is, the laminated foam board of this invention can suppress that the expression of the feel of a covering sheet is inhibited by reflected light.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic perspective view which showed the laminated foam board of one Embodiment. The enlarged view which expanded the A section of FIG. 1 in order to show the laminated structure of a laminated foam board. The schematic side view which shows the example of an apparatus for enforcing the manufacturing method of a foam board. BRIEF DESCRIPTION OF THE DRAWINGS The schematic plan view which shows the example of an apparatus for enforcing the manufacturing method of a foam board. (A) Schematic top view which shows perforation | piercing apparatus, (b) Schematic side view of perforation | piercing apparatus. The figure which showed the laminated foam board for folding box formation. The schematic perspective view which showed the folding box (container for foodstuffs). The figure which showed the laminated foam board for perimeter side frame formation. The schematic perspective view which showed the folding box (container for foodstuffs).

Embodiments according to the present invention will be described below.
First, a laminated foam board according to the present embodiment will be described.
The laminated foam board according to the present embodiment includes a polystyrene resin foam board 1 and covering sheets 2 and 3 laminated on both sides of the polystyrene resin foam board, as shown in FIGS.
The covering sheets 2 and 3 are laminated on the polystyrene resin foam board 1 via an adhesive coated on the surface of the polystyrene resin foam board 1.
The covering sheets 2 and 3 of the present embodiment have a laminated structure in which inner and outer two layers are formed.
The outer layers (layers provided on the most surface side) of these covering sheets 2 and 3 are resin film layers 21 and 31.
Further, the inner layers of the facing sheets 2 and 3 (layers in contact with the resin film layers 21 and 31 from the inside) are paper sheet layers 22 and 32.

  That is, in the surface layer portion of the laminated foam board 10 of the present embodiment, the resin film layers 21 and 31, the paper sheet layers 22 and 32, and the adhesive layers 41 and 42 are directed from the outermost surface toward the central portion in the thickness direction. It is equipped.

The polystyrene resin foam board 1 in the present embodiment is an extruded foam product formed of a polystyrene resin composition.
In the polystyrene resin foam plate 1 of the present embodiment, a polystyrene resin composition containing a foaming agent is melt-kneaded at a temperature higher than the softening point of the polystyrene resin in an extruder equipped with a circular die having an annular discharge port. After that, it is formed by extrusion foaming from the discharge port.
More specifically, in the polystyrene resin foam board 1 of this embodiment, the melt-kneaded polystyrene resin composition is extruded as a cylindrical foam from the discharge port, and the inner peripheral surface of the foam cools. The foam is sandwiched between a pair of pinch rollers without cutting, and the inner peripheral surfaces are heat-sealed together and the whole shape is adjusted in a plate shape.

The polystyrene-based resin foam plate 1 of the present embodiment will be described in more detail. The polystyrene-based resin foam plate 1 is manufactured using an apparatus as shown in FIGS. 3 to 5.
In FIGS. 3 to 5, the arrow X indicates the extrusion direction, that is, the advancing direction of the foam.
Further, in FIGS. 3 and 4, reference numeral 100 denotes a circular die, and the description of apparatuses such as an extruder on the upstream side of the circular die 100 will be omitted.

As also shown in this figure, in the apparatus for producing a polystyrene resin foam board 1 according to the present embodiment, a cylindrical foam 200 (hereinafter referred to as “cylindrical foam” is produced by extruding and foaming a polystyrene resin composition. The circular die 100 is disposed to form the body 200 ′ ′, and the circular die 100 is disposed with its annular discharge holes directed in the horizontal direction.
That is, the circular die 100 is disposed so as to extrude and foam the cylindrical foam 200 in a cylindrical shape centered on a horizontal imaginary line passing through the center of the discharge hole.

  The manufacturing apparatus sandwiches the cylindrical foam 200 extruded from the circular die 100 from the top and the bottom in the extrusion direction forward of the circular die 100, and the upper half 201 of the foam 200 (hereinafter also referred to as "upper sheet 201") And a lower half 202 (hereinafter also referred to as "lower sheet 202") are heat-sealed together to form a pair of foam rolls 203, and a foam sheet 203 formed by the pinch rolls 101. A take-off device 104 is further provided downstream of the pinch roll 101.

The manufacturing apparatus includes an air ring 103 for air cooling the outer surface of the cylindrical foam 200 immediately after being extruded from the circular die 100, and a pinch roll of the cylindrical foam 200 air cooled by the air ring 103. A plurality of upper and lower pairs of guide rollers 102 are provided for guiding to 101.
The manufacturing apparatus is configured such that when the inner surface of the cylindrical foam 200 is heat-fused by the pinch roll 101, the gas vent holes for releasing the gas inside the cylindrical foam 200 to the outside are left and right of the cylindrical foam 200. The perforating apparatus 106 is provided between the pinch roll 101 and the guide roller 102 for perforating.

  As shown in FIG. 5, the perforation device 106 includes a plurality of needle-like objects 106b provided around a rotatable roller 106a, and in the present embodiment, the perforation device 106 is provided with a driving force. Of the cylindrical foam 200 by pressing the needle-like object 106b radially projecting outward from the roller 106a radially against the side surface of the cylindrical foam 200 advancing in the extrusion direction X. It is comprised so that the said degassing hole can be drilled in the side surface of this cylindrical foam 200, co-rotating with advancing.

  The manufacturing apparatus arranges the piercing devices 106 one by one on the left and right of the cylindrical foam 200, and adjusts the distance between the piercing devices disposed as a pair of left and right to form the width of the foam plate to be produced. It is configured to be able to adjust.

The perforation device 106 is preferably disposed on the left and right of the cylindrical foam 200 so as to position the needles 106 b on a horizontal surface passing through the center of the cylindrical foam 200, and the gas perforated by the needles 106 b It is desirable to arrange so that a punching hole may be located in the return parts 2011 and 2012 of the cylindrical foam 200.
Note that although the folded portions 2011 and 2012 are cut and removed by the cutter 105 in order to be a product, it is possible to provide the degassing holes in the folded portions 2011 and 2012 by doing as described above. , The parts that need to be removed by the cutter can be minimized.

As a foam plate 203 manufactured using such a manufacturing apparatus, for example, a polystyrene resin composition containing a polystyrene resin and a cell regulator, has a density of 0.035 g / cm ^{3 to} 0.12 g / cm. What was made to foam with a foaming agent so that it may become ³ is mentioned.
Moreover, as a foam board 203 manufactured using the above manufacturing apparatuses, the foam board of width 500 mm or more and 1500 mm or less which has thickness of 1 mm or more and 15 mm or less, preferably 3 mm-10 mm is mentioned.
In addition, the density of the foam board in this specification means the "apparent density" measured based on JISK7222: 2005 "foamed plastics and rubber-how to obtain | require an apparent density."

The polystyrene resin foam board 1 of this embodiment is produced by processing the foam board 203 produced in this manner into a predetermined shape.
When producing polystyrene-based resin foam plate 1 having a rectangular shape in plan view, the foam plate 203 is cut so that the length in the extrusion direction (MD) becomes a desired length, and the width direction of the cut pieces (the extrusion direction and The directions orthogonal to each other may be cut along the extrusion direction.

  As a polystyrene resin which becomes a main component of polystyrene resin foam board 1, For example, styrene, alpha-methylstyrene, vinyl toluene, ethylstyrene, i-propylstyrene, t-butylstyrene, dimethylstyrene, bromostyrene, chlorostyrene Homopolymers of styrenic monomers such as, and copolymers of these, and copolymerization with the styrenic monomers, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl ( Alkyl (meth) acrylates, alkyl (meth) acrylates such as cetyl (meth) acrylate, (meth) acrylonitrile, dimethyl maleate, dimethyl fumarate, diethyl fumarate, ethyl fumarate, divinyl benzene, dialkylene benzene dimethacrylate, etc. With monomer, before Least one selected from a copolymer of styrene monomer.

The polystyrene resin foam board 1 of this embodiment is produced using a cell regulator, a foaming agent, and various additives in addition to such a polystyrene resin.
As components other than the polystyrene resin, the same ones as used in the production of the conventional foam plate can be adopted.
For example, as the above-mentioned cell regulator, talc, mica, silica, diatomaceous earth, aluminum oxide, titanium oxide, zinc oxide, magnesium oxide, magnesium hydroxide, aluminum hydroxide, calcium hydroxide, potassium carbonate, calcium carbonate, magnesium carbonate, Inorganic compounds such as potassium sulfate, barium sulfate, glass beads, and organic compounds such as polytetrafluoroethylene can be employed.

As the blowing agent, hydrocarbons such as propane, normal butane, isobutane, normal pentane, isopentane and the like can be adopted, and in addition, water, dimethyl ether, methyl chloride, ethyl chloride, nitrogen, carbon dioxide, argon and the like are adopted. It is also possible.
As the foaming agent, it is also possible to adopt a compound particle which is thermally decomposed to generate a gas, and as the compound particle, for example, azodicarbonamide, sodium hydrogencarbonate, a mixture of sodium hydrogencarbonate and citric acid, etc. Can be used.

The polystyrene resin foam board 1 may be a natural color (usually milky white), but in consideration of the appearance of the laminated foam board 10, it is preferable to be colored with a pigment.
Therefore, the polystyrene resin composition for forming the polystyrene resin foam board 1 may contain additives, such as a pigment.
Furthermore, as an additive which can be contained in the polystyrene resin composition, for example, various stabilizers such as weathering agent and anti-aging agent, processing aids such as lubricant, slip agent, anti-fogging agent, anti-mold agent, antibacterial agent, Functional agents such as antistatic agents, and perfumes may be mentioned.

The type of the adhesive for bonding the covering sheets 2 and 3 to the polystyrene resin foam plate 1 is not particularly limited, and a widely used adhesive may be employed.
That is, as the adhesive for forming the adhesive layers 41 and 42, for example, a reaction curable adhesive, a pressure sensitive adhesive, a hot melt adhesive and the like can be mentioned.
The adhesive may be a solvent based adhesive or an emulsion based adhesive.
Adhesive layer 41 (hereinafter, also referred to as "first adhesive layer 41") provided on one surface side of polystyrene resin foam plate 1 and adhesive layer 42 (hereinafter, second adhesive layer) provided on the other surface side In the case of “42”, the kind of adhesive to be used and the layer thickness may be different, or they may be common.

Of the covering sheets 2 and 3 laminated on the polystyrene resin foam board 1 with the adhesive, the resin film layers 21 and 31 can be made of a general resin film.
A resin film layer 21 (hereinafter, also referred to as "first resin film layer 21") provided on one side of polystyrene resin foam plate 1 and a resin film layer 31 (hereinafter, second resin film) provided on the other side The layers 31 ′ ′ may be different from each other in thickness or forming material, or may be common.
However, it is important that at least one of the first resin film layer 21 and the second resin film layer 31 has a surface glossiness of 2 or more and 20 or less in a state where the laminated foam plate 10 is formed. .
The glossiness is preferably 2 or more and 15 or less, and more preferably 2 or more and 9 or less.
If the glossiness of the surface is equal to or more than the lower limit value of the above range, it becomes a laminated foam board which has an appropriate glossiness and the texture of the covering sheet is easily exhibited sufficiently.
If the glossiness of the surface is below the upper limit value of the above range, a part of the laminated foam board is difficult to be whitened by the reflected light, and it becomes a laminated foam board where the texture of the covering sheet is easily exhibited sufficiently.
The glossiness of the surfaces of the first resin film layer 21 and the second resin film layer 31 is preferably 2 or more and 20 or less.
The glossiness of both film layers is more preferably 2 or more and 15 or less, and still more preferably 2 or more and 9 or less.
If the glossiness of the surface is equal to or more than the preferable lower limit value of the above range, both sides have an appropriate glossiness, and a laminated foam board is easily obtained in which the texture of the covering sheet is sufficiently exhibited. If the glossiness of the surface is not more than the preferable upper limit value of the above range, a part of the laminated foam plate is hardly whitened by the reflected light on both sides, and the coated foam sheet is apt to fully exhibit the texture of the covering sheet.

In addition, the glossiness of the surface of a resin film layer can be calculated | required by performing the following measurement.
Specifically, the glossiness of the surface of the resin film layer side of the laminated foam plate was set to an incident angle of 60 ° and calibrated. A gloss checker (Handy gloss meter, manufactured by Horiba, Ltd., model: IG- The sensor portion 330) is brought into close contact with the surface of the resin film layer without any gap, and the center position mark of the gloss checker is lightly pressed for measurement.
For calibration, a standard plate with a 90 degree gloss at an incident angle of 60 ° is used.
The measurement is carried out at any five points, and the average value is taken as the gloss of the surface of the resin film layer.
The test environment is a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5%.

In order to exhibit the surface glossiness as described above more reliably on the surface of the laminated foam board 10, the resin film layers 21 and 31 preferably have an arithmetic average roughness (Ra) of 1 μm to 15 μm.
The arithmetic average roughness (Ra) is more preferably 1.5 μm or more and 10 μm or less, and still more preferably 1.5 μm or more and 8 μm or less.
If the arithmetic mean roughness (Ra) is equal to or more than the preferable lower limit value of the above range, a part of the laminated foam plate is difficult to be whitened by the reflected light, and the laminated foam plate is easily formed.
If the arithmetic average roughness (Ra) is not more than the preferable upper limit value of the above range, it has a suitable feeling of unevenness and tends to be a laminated foam board in which the texture of the covering sheet is easily exhibited sufficiently.

As a specific method of making the resin film layers 21 and 31 have the above-mentioned arithmetic average roughness (Ra) and surface glossiness, for example, the thickness of a paper sheet to be laminated on a resin film, the resin type of the resin film, The method of adjusting the ratio (Mw / Mn) of the degree of crystallinity, the number average molecular weight (Mn), the mass average molecular weight (Mw) to the number average molecular weight (Mn), etc. may be mentioned.
Alternatively, for example, a method of surface treatment such as embossing, drilling, blasting, hairline processing or the like may be performed on the covering sheets 2 and 3 or the resin film before being incorporated into the covering sheets 2 and 3.
In the case where convex lines and concave lines are formed on the surfaces of the resin film layers 21 and 31 and the unevenness due to these is formed in a directional form such as a corrugated sheet, for example, the glossiness depends on the measurement direction It is possible that it differs greatly.
Although the measurement of the glossiness is carried out at five points arbitrarily selected in principle as described above, it is preferable that directional irregularities are formed on the surfaces of the resin film layers 21 and 31. In the case, the measurement may be performed at five or more places so as to obtain reproducibility in the result.
As described above, when the measurement of glossiness is performed at five or more places, it is desirable that the measurement direction with respect to the direction in which the unevenness is formed be different for each measurement.

The average thickness of the first resin film layer 21 and the second resin film layer 31 is preferably 5 μm or more and 50 μm or less.
The average thickness of the first resin film layer 21 and the second resin film layer 31 is more preferably 8 μm or more and 45 μm or less, and still more preferably 10 μm or more and 40 μm or less.
If the average thickness of the resin film layer is not less than the preferable lower limit value of the above range, the paper sheet layer is likely to be protected by the resin film from abrasion and water wetting.
If the average thickness of the resin film layer is equal to or less than the preferable upper limit value of the above range, the unevenness of the surface of the polystyrene resin foam plate is easily transferred, and the laminated foam plate having a calm texture is easily formed.

The arithmetic mean roughness (Ra) of the surface of the laminated foam plate on the resin film side and the arithmetic mean roughness (Ra) of the polystyrene resin foam plate can be measured according to JIS B0601: 2001.
Specifically, arithmetic mean roughness (Ra) can be measured using a “double scan high precision laser measuring instrument LT-9500, LT-9010M” manufactured by Keyence Corporation as a measuring apparatus, and COMS CO., LTD. As data processing software. It can measure using "non-contact outline shape roughness measurement system MAP-2DS" made in Japan.
The measurement conditions are: 20000 μm measurement, 10 μm measurement pitch, 500 μm / sec measurement speed, 12.5 mm evaluation length (Ln), 2.5 mm reference length (L), light amount 40, average filter 4 and noise filter 1 The arithmetic mean roughness (Ra) of the contour curve is measured under the measurement conditions.
In addition, the size of the test piece extract | collected from a lamination | stacking foam board or a polystyrene-type resin foam board shall be width 100 mm * length 100 mm, and the number of the test pieces to extract | collect 5 samples arbitrarily.
Then, for each of the test pieces, outline curves in the MD direction (extrusion direction) and TD direction (direction orthogonal to the extrusion direction on the plate surface) of the laminated foam plate or the polystyrene resin foam plate are collected, Calculate arithmetic mean roughness (Ra).
The average value of each test piece of arithmetic mean roughness (Ra) in the MD direction (extrusion direction) and the average value of each test piece of arithmetic mean roughness (Ra) in the TD direction are determined, respectively. The arithmetic mean roughness (Ra) of the surface of the laminated foam plate on the resin film layer side and the arithmetic mean roughness (Ra) of the polystyrene resin foam plate are used.
If it is not possible to specify the MD direction (extrusion direction) or TD direction (direction orthogonal to the extrusion direction on the plate surface) of the laminated foam plate or polystyrene resin foam plate, MD in any direction on these surfaces can be MD Let the direction be a direction orthogonal to the MD direction on the surface be the TD direction.
The values of the arithmetic mean roughness (Ra) of the surface on the film layer side of the laminated foam plate and the arithmetic mean roughness (Ra) of the polystyrene resin foam plate can be determined whether the extrusion direction can be specified or not. It will be almost the same.
In the case where convex lines and concave lines are formed on the surfaces of the resin film layers 21 and 31 and unevenness due to these is formed in a directional form such as, for example, a corrugated sheet shape, arithmetic average roughness (Ra) Similarly to the glossiness, it is conceivable that the measurement results largely differ depending on the measurement direction.
Therefore, in the case where convex lines and concave lines are formed on the surfaces of the resin film layers 21 and 31 and the unevenness due to these is formed in a directional form, arithmetic is performed only in two directions of the MD direction and the TD direction. It is desirable to determine the arithmetic mean roughness (Ra) in a random direction rather than measuring the mean roughness (Ra).
That is, in the above-mentioned method, since measurement in two directions is performed on each of five test pieces, measurement is performed ten times in total, but unevenness having directivity is the surface of the resin film layers 21 and 31. In the case where the test piece is formed, measurement in three or more directions may be performed on each of five test pieces so as to obtain reproducibility in the result.

The average thickness of the resin film layers 21 and 31 is determined by observing the cross section of the laminated foam plate 10 with a scanning electron microscope or an optical microscope and measuring the thickness at a plurality of randomly selected locations (for example, 20 locations), It can be determined as an arithmetic mean value of the thicknesses of the plurality of places obtained.
The average thickness of the paper sheet layers 22 and 32 and the adhesive layers 41 and 42 can be determined by the same method.
If the thickness of the resin film layers 21 and 31 largely fluctuates in one micrograph by surface processing such as embossing or drilling as described above, measure the thickness of a specific location. Alternatively, the cross-sectional area of the resin film layer in a section of a fixed length may be determined, and the value obtained by dividing the cross-sectional area by the section length may be measured as the thickness of the resin film layer in the section.

  The first resin film layer 21 and the second resin film layer 31 preferably have excellent transparency, and the haze measured based on JIS K 7136: 2000 is preferably 10% or less, and 8% or less. It is more preferable that it be 5% or less.

  The first resin film layer 21 and the second resin film layer 31 are preferably colored and transparent or colorless and transparent, and more preferably colorless and transparent.

The resin film layers 21 and 31 are preferably formed of a polyolefin resin film.
Examples of the polyolefin resin contained in the polyolefin resin film include polyethylene resin, polypropylene resin, ethylene-α-olefin copolymer and the like.
The polyolefin resin contained in the polyolefin resin film has a crystallinity of 15% to 80%, a number average molecular weight (Mn) of 1 × 10 ^{4 to} 1 × 10 ⁵ , and a number average molecular weight (Mn) It is preferable that the ratio (Mw / Mn) of the mass mean molecular weight (Mw) with respect to is 2.0 or more and 15.0 or less.
The polyolefin resin has a crystallinity of 20% to 75%, a number average molecular weight (Mn) of 1 × 10 ^{4 to} 9 × 10 ⁴ , and a mass average molecular weight (Mw) relative to the number average molecular weight (Mn). The ratio of (Mw / Mn) is more preferably 3.0 or more and 14.0 or less.
The crystallinity of the polyolefin resin is 25% or more and 70% or less, the number average molecular weight (Mn) is 1 × 10 ⁴ or more and 8 × 10 ⁴ or less, and the mass average molecular weight (Mw) relative to the number average molecular weight (Mn) More preferably, the ratio of (Mw / Mn) is 4.0 or more and 13.0 or less.
If the degree of crystallinity is equal to or more than the preferable lower limit value of the above range, the resin film layer tends to be easily exhibited sufficiently the feeling of the covering sheet.
If the degree of crystallinity is equal to or less than the preferable upper limit value in the above range, the resin film layer is likely to be sufficiently easy to exert the texture of the covering sheet.
If the number average molecular weight (Mn) is equal to or more than the preferable lower limit value of the above-mentioned range, it tends to be a resin film layer which easily exerts the texture of the covering sheet sufficiently.
If a number average molecular weight (Mn) is below the preferable upper limit of the said range, it will be easy to become a resin film layer which is easy to fully demonstrate the feel of a covering sheet.
If the ratio (Mw / Mn) of the mass average molecular weight (Mw) to the number average molecular weight (Mn) is equal to or more than the preferable lower limit value of the above range, the resin film layer tends to easily exhibit the texture of the covering sheet.
If the ratio (Mw / Mn) of the mass average molecular weight (Mw) to the number average molecular weight (Mn) is not more than the preferable upper limit value of the above range, the resin film layer tends to easily exhibit the texture of the covering sheet.
The polyolefin resin is preferably a polyethylene resin having a melting point of 100 ° C. or more and 120 ° C. or less.
The melting point of the polyolefin-based resin is more preferably 101 ° C. or more and 119 ° C. or less, and the melting point is more preferably 102 ° C. or more and 118 ° C. or less.
If melting | fusing point is more than the preferable lower limit of the said range, it will be easy to become a resin film which is easy to fully exhibit the feel of a covering sheet.
If melting | fusing point is below the preferable upper limit of the said range, it will be easy to become a resin film which is easy to fully exhibit the feel of a covering sheet.
The polyolefin resin film may contain additives such as a modifier, a slip agent, an antioxidant, and an antibacterial agent, in addition to the above-described polyolefin resin.
The total value of the content of all the additives in the polyolefin resin film is usually 2% by mass or less.

The crystallinity of the polyolefin resin is calculated from the heat of crystallization measured by the method described in JIS K 7122: 2012 “Method of measuring heat of transition of plastic”.
However, the sampling method and temperature conditions are as follows.
Using a differential scanning calorimeter (for example, “DSC 6220 type”, SII Nano Technology Co., Ltd.), approximately 6 mg of a sample cut out from the resin film layer is filled with nitrogen gas so that the bottom of the aluminum measurement container is clear. Under a flow rate of 20 mL / min, the temperature is lowered from 30 ° C to -40 ° C and then held for 10 minutes. Cooling, after holding for 10 minutes, a DSC curve is obtained when the temperature is raised from -40 ° C to 220 ° C (2nd Heating).
In addition, all temperature rising / falling is performed at a rate of 10 ° C./min, and alumina is used as a reference substance.
Here, the degree of crystallization calculated from the amount of heat of crystallization is obtained by dividing the amount of heat of crystallization (J / g) obtained from the area of the crystallization peak observed in the cooling process by the theoretical heat of fusion of polyolefin perfect crystals It is a ratio.
For example, when the polyolefin resin is polyethylene, the degree of crystallization can be determined by dividing the amount of heat of crystallization (J / g) by the theoretical amount of heat of fusion of 285.7 J / g.
The heat of crystallization is analyzed by using the analysis software attached to the device, and a straight line connecting the point where the DSC curve leaves the baseline on the high temperature side and the point where the DSC curve returns to the baseline on the low temperature side again Calculated from the area of
That is, the degree of crystallinity can be obtained by the following equation.
PE: degree of crystallinity (%) = [heat of crystallization (J / g) /285.7 (J / g)] × 100
Further, for example, when the polyolefin resin is polypropylene, the crystallization heat (J / g) can be divided by the theoretical heat of fusion 209.5 J / g to obtain the degree of crystallinity.
The heat of crystallization is analyzed by using the analysis software attached to the device, and a straight line connecting the point where the DSC curve leaves the baseline on the high temperature side and the point where the DSC curve returns to the baseline on the low temperature side again Calculated from the area of
That is, the degree of crystallinity can be obtained by the following equation.
PP: degree of crystallinity (%) = [heat of crystallization (J / g) /209.5 (J / g)] × 100

The number average molecular weight and the mass average molecular weight of the polyolefin resin mean polystyrene (PS) converted value measured by an internal standard method using gel permeation chromatography (GPC).
Specifically, the number average molecular weight and the mass average molecular weight of the polyolefin resin can be determined as follows.
First, 4 mL of O-dichlorobenzene was added to 10 mg of the sample, and sealed tightly, heated and dissolved at 160 ° C. for 2 hours with Tosoh Co., Ltd. product DF-8020, completely dissolved, and then filtered by high temperature GPC The solution is transferred to a dedicated stainless steel container for SSC-9300) and heated again at 160 ° C. After that, air is sent to the dedicated stainless steel container with a dedicated air injection tool and filtration is performed to prepare a sample solution.
As MEMBRANE FILTER used for filtration, ADVANTEC company PTFE (0.5 micrometer) 25 mm (T050A025A) is used.
Determine the Mw and Mn of the sample from the calibration curve of standard polystyrene which is measured using a chromatograph under the following measurement conditions and measured and prepared in advance, and Mw / Mn is calculated from each of the obtained average molecular weights .

Device used: Tosoh Corporation HLC-8121GPC / HT
Guard column: Tosoh TSKguard column HHR (S) HT 1 (7.5 mm ID × 7.5 cm) × 1 column: Tosoh TSKgel GMHHR-H (S) HT (7.8 mm I. D . × 30 cm) × 2 Mobile phase: o-Dichlorobenzene reference flow rate: 1.0 mL / min
Sample flow rate: 0.5mL / min
Detector: RI detector sample concentration: 0.17 wt%
Injection volume: 300 μL
Measurement time: 40 min
Sampling pitch: 300 msec

<Device part set temperature>
Solvent stocker: 50 ° C
System oven: 40 ° C
Pre-oven: 145 ° C
Column oven (column temperature): 145 ° C
Sample table: 145 ° C
Injection valve: 145 ° C
Transformer line: 145 ° C
Waste line: 145 ° C
Detector: 145 ° C

Standard polystyrene samples for calibration curve are manufactured by Showa Denko, trade name "Shodex", mass average molecular weight is 5,620,000, 3,120,000, 1,250,000, 442,000, 131,000, 54, Those of 000, 17,000, 7, 660, 2, 900, and 1,320 are used.
The standard polystyrenes for the above calibration curve are A (5,620,000, 1,250,000, 131,000, 17,000, 2,900) and B (3, 120,000, 442,000, 54,000, After grouping into 7, 660 and 1,320, 3 to 10 mg of A is dissolved in 50 mL of o-dichlorobenzene and B is dissolved in 50 mL of o-dichlorobenzene after 3 to 10 mg each.
A standard polystyrene calibration curve is obtained by injecting 300 μL of the prepared A and B solutions and preparing a calibration curve (tertiary expression) from the retention time obtained after measurement.
Mw and Mn can be determined using the calibration curve, and Mw / Mn can be calculated from the obtained respective average molecular weights.

The melting point of the polyolefin-based resin is measured by the method described in JIS K 712: 2012 "Method for measuring transition temperature of plastic".
However, the sampling method and temperature conditions are as follows.
Using a differential scanning calorimeter (for example, “DSC 6220 type”, SII Nano Technology Co., Ltd.), approximately 6 mg of a sample cut out from the resin film layer is filled with nitrogen gas so that the bottom of the aluminum measurement container is clear. Under a flow rate of 20 mL / min, the temperature is lowered from 30 ° C to -40 ° C and then held for 10 minutes. Cooling, after holding for 10 minutes, a DSC curve is obtained when the temperature is raised from -40 ° C to 220 ° C (2nd Heating).
In addition, all temperature rising / falling was performed at a rate of 10 ° C./min, and alumina was used as a reference substance.
Here, the melting point is a value obtained by reading the temperature at the top of the melting peak observed in the 2nd heating process using analysis software attached to the apparatus.

It is preferable that the paper sheet layers 22 and 32 in contact with the resin film layers 21 and 31 from the inside have an average thickness of 20 μm or more and 170 μm or less.
The thickness of the paper sheet layers 22 and 32 is more preferably 30 μm or more and 120 μm or less, and still more preferably 40 μm or more and 100 μm or less.
If the average thickness of the paper sheet layer is equal to or more than the preferable lower limit value of the above range, it becomes easy to become a covering sheet excellent in the interleaving property that breakage and wrinkles hardly occur when laminating the covering sheet on the polystyrene resin foam board.
If the average thickness of the paper sheet layer is equal to or less than the preferable upper limit value in the above range, the unevenness of the surface of the polystyrene resin foam plate is easily transferred, and the laminated foam plate having a calm texture is easily formed.
The thickness of the paper sheet layer and the thickness of the resin film layer can be measured by a scanning electron microscope (for example, Hitachi High-Technologies Corp., “S-3400N” or In SU 1510 ′ ′), the measurement can be performed by enlarging about 100 to 1000 times.
The measurement is performed at any five points, and the thickness of each layer is the average value thereof.

  A paper sheet layer 22 (hereinafter also referred to as "first paper sheet layer 22") provided on one side of polystyrene resin foam plate 1 and a paper sheet layer 32 (hereinafter referred to as "second The paper sheet layer 32 ′ ′ may be different from or in common with each other in thickness and formation material.

The paper sheet layers 22 and 32 can be formed of a paper-like sheet obtained by sheeting pulp fibers, synthetic resin fibers, inorganic fibers, and mixed fibers thereof with a wet method or a dry method.
Further, it is also possible to adopt a sticky board or the like obtained by slicing wood to a thickness of 300 μm or less as a paper-like sheet for forming the paper sheet layers 22 and 32.

Preferably, at least one of the first paper sheet layer 22 and the paper sheet layer 32 is printed on the side in contact with the resin film layers 21 and 31.
Both the first paper sheet layer 22 and the second paper sheet layer 32 are preferably printed.

The printing on the paper sheet layers 22 and 32 may be, for example, solid printing or design.
The design can be a geometric pattern or an animal or plant.
For example, in the case where the paper sheet layer is formed of a paper-like sheet, silkworm, chrysanthemum, kanoko, arabesque, moth-shaped, moth, collapsing, collapsing, checkered, pine skin, flowering, mallet, turtle shell, yacon, hemp leaf, It is possible to adopt a paper-like sheet on which patterns such as cloisonne, running water and blue sea waves are printed.
Moreover, the paper-like sheet may be subjected to woodgrain printing, and examples of the woodgrain pattern include grain patterns and grain patterns.
In the case of applying such a design, the resin foam layer 21 or 31 can be made to be excellent in aesthetic appearance by forming unevenness corresponding to the design on the resin film layers 21 and 31 by the above-mentioned embossing or the like.
In this regard, for example, in the case of applying a woodgrain design, the resin film layers 21 and 31 are formed with the concavities and convexities corresponding to the grain by forming ridges or grooves extending in the direction along the grid pattern. Thus, the laminated foam board 10 can exhibit an excellent wood texture.

In addition, it is preferable to give printing of a woodgraining to a paper-like sheet in the point which can make the laminated foam board 10 exhibit a wood texture.
In that case, it is preferable to color the polystyrene resin foam plate 1 to the color defined below.
By coloring in this manner, it is possible to make the surface of the polystyrene resin foam board 1 and the wood surface (cut surface) have a wood texture.
The surface of the polystyrene-based resin foam board 1 has “45 ≦ L ^* ≦ 85”, “0 ≦ a ^* ≦ + 30”, “+ 5 ≦” in the color specification of L ^* , a ^* , b ^* defined below. It is preferable to have a color represented by b ^* ≦ + 35.
The values of L ^* , a ^* and b ^{* on} the surface of the polystyrene resin foam plate 1 are measured according to the method described in JIS Z 8222: 2009 "Measurement method of color-reflection and transmission object color".
That is, using a spectrometric colorimeter (for example, "SE-2000", made by Nippon Denshoku Kogyo Co., Ltd., and data processing "Color Mate 5", made by Nippon Denshoku Kogyo Co., Ltd.) A test piece with a thickness of 3 to 6 mm is pressed against the back with a light source (D 65/10 visual field), and measurement is performed by a reflection method using a dedicated white board.
The reference color is the color of the standard plate, and L ^* , a ^* and b ^* of the test strip are measured.
However, after conditioning the test piece at a temperature of 23 ± 2 ° C. and a humidity of 50 ± 5% for 24 hours or more, the test environment is measured at a temperature of 20 ± 2 ° C. and a humidity of 65 ± 5%.
As a standard plate, one having a tristimulus value (C / 2), Y = 96.09, X = 94.13, Z = 113.36 is used.
Five test pieces are prepared, and the average value of the values obtained from each test piece is taken as L ^* , a ^* , b ^{* on} the surface of the polystyrene resin foam board 1.
When the covering sheet is laminated on one side of the polystyrene resin foam board 1, the surface of the polystyrene resin foam board 1 on the side on which the covering sheet is not laminated is measured.
When the covering sheet is laminated on both sides of the polystyrene resin foam board 1, the covering sheet is peeled off and the surface of the polystyrene resin foam board 1 is measured.
In either case, the color of the surface is also reflected in the color of the wood surface (cross section), and the surface and the wood surface (cross section) have substantially the same color.

When the colored surface of polystyrene foam foam plate 1 has a density of air bubbles in the thickness direction, the same texture as when wood forms annual rings by the density of cell walls is polystyrene resin. It can be made to exhibit on the cut surface of the foam board 1.
Therefore, in order to exhibit wood texture, it is preferable that the average cell diameter of the polystyrene resin foam board 1 fluctuates in the thickness direction.
Specifically, the thickness of the polystyrene-based resin foam plate 1 is t (mm), and the polystyrene-based resin foam plate 1 has an average cell diameter _Dz1 ("Z1" in FIG. 2) in the central portion in the thickness direction. (μm), and the average bubble diameter at both sides (for example, depth t / 4 (mm) from the surface, “Z2”, “Z3” in FIG. 2) with D _z2 (μm), D _z3 (μm) When doing, it is preferable to satisfy both of the following relational expression (1) and the relational expression (2).

D _z2 〔[1.2 × D _z1 ] (1)
D _z3 〔(1.2 × D _z1 ) (2)

The average cell diameter in each part of the polystyrene resin foam board 1 can be measured by the following test method.
The polystyrene resin foam board 1 is cut perpendicularly to the surface of the polystyrene resin foam board 1 along the MD direction (extrusion direction) and the TD direction (direction orthogonal to the extrusion direction on the surface of the polystyrene resin foam board 1) The section taken out is photographed with a scanning electron microscope (for example, “S-3400N” or “SU1510” manufactured by Hitachi High-Technologies Corp.) magnified 20 to 100 times.
At this time, the magnification of the electron microscope is adjusted so that the number of air bubbles present on a 60 mm straight line drawn on the printed photograph is about 10 to 20.
The photographed image is printed on one sheet of A4 sheet oriented in the horizontal direction (an image of two fields of view from the cross section in the MD direction and an image of two fields of view from the cross section in the TD direction).
In the case of the cross section in the MD direction, three straight lines (length 60 mm) parallel to the MD direction are drawn in each of the images of the two fields of view.
In the case of the cross section in the TD direction, three straight lines (length 60 mm) parallel to the TD direction are drawn in each of the images of the two fields of view.
In addition, an image of one field of view in the MD direction and an image of one field of view in the TD direction are parallel to the VD direction (the direction perpendicular to the MD or TD direction, the thickness direction of the polystyrene resin foam board 1). Three straight lines (length 60 mm) are drawn, and a 60 mm straight line parallel to the MD, TD, and VD directions is drawn six each.
The number of bubbles counted for six straight lines (length 60 mm) in each direction of MD, TD and VD is arithmetically averaged to obtain the number of bubbles in each direction.
From the magnification of the image obtained by counting the number of bubbles and the number of bubbles, the average chord length (t) of the bubbles is calculated by the following equation.
Average chord length t (mm) = 60 / (number of bubbles × image magnification)

However, when the thickness of the test piece is small and the number of bubbles of 60 mm in length can not be counted in the VD direction (thickness direction of polystyrene resin foam board 1), 30 mm or 20 mm in length instead of 60 mm in length Calculate the number of bubbles on a straight line and convert it to the number of bubbles on a straight line of 60 mm (for example, when there are 5 bubbles on a straight line of 30 mm in length, 10 bubbles on a straight line of 60 mm in length It is considered that there were individual).
The optional straight line allows the bubbles to penetrate as much as possible rather than only contacting the bubbles at points.
If some bubbles contact at a straight point, this bubble is also included in the number of bubbles.
If the end point of the straight line is located in a bubble, this bubble is also included in the bubble number.
The magnification of the image is obtained by measuring the scale bar on the image to 1/100 mm with “Digimatic Caliper” manufactured by Mitutoyo Co., Ltd.

Image magnification = Scale bar actual value (mm) / Scale bar display value (mm)

Then, the bubble diameter in each direction is calculated by the following equation.

D (mm) = t / 0.616

Further, the cube root of the product of them is taken as the average bubble diameter.
Average bubble diameter (mm) = ( _DMD x _DTD x D _VD ) ^1/3

D _MD : Bubble diameter in the MD direction (mm)
D _TD : Bubble diameter in the TD direction (mm)
D _VD : Bubble diameter in the VD direction (mm)

In this measurement, the average cell diameter is measured at portions corresponding to “Z1”, “Z2”, and “Z3”, and D _Z1 (μm), D _Z2 (μm), and D _Z3 (μm), respectively.
If the MD direction (extrusion direction) or the TD direction (direction orthogonal to the extrusion direction on the surface of the foam plate 1) of the polystyrene resin foam plate 1 can not be specified, any one of them can be selected on the surface of the polystyrene resin foam plate 1. The direction is taken as the MD direction, and the direction orthogonal to the MD direction on the surface of the polystyrene resin foam board 1 is taken as the TD direction.
The value of the average bubble diameter is almost the same whether the direction can be identified or not.

In the laminated foam board 10 of the present embodiment, since the resin film layer is provided on the surface of the paper sheet layer, the paper sheet constituting the paper sheet layer is protected by the resin film from abrasion and water wetting.
Therefore, the aesthetic appearance developed by the paper sheet is exhibited for a long time.
In addition, since the resin film layer has a specific surface gloss, the reflection of light is suppressed, and there is a low possibility that the reflected light may be damaged by the angle at which the aesthetic appearance developed by the paper sheet is viewed.

  In the present embodiment, a laminated foam board in which the covering sheet is laminated on both sides of the polystyrene resin foam board is exemplified, but in the laminated foam board of the present invention, the covering sheet is only on one side of the polystyrene resin foam board. It may be laminated.

The laminated foam board of the present embodiment can be, for example, a forming material of a folding box as shown in FIGS. 6 and 7 or a forming material of a peripheral side frame for folding box as shown in FIGS.
Note that the folding box BX in the present embodiment includes one or more corner portions CP, and more specifically, has a rectangular parallelepiped shape.
The folded box BX shown in FIG. 7 is formed of a flat laminated foam plate 10x as shown in FIG. 6, and is formed of the laminated foam plate 10x cut into a rectangular parallelepiped development view.
The laminated foam board 10x is divided to form a total of six parts, that is, one bottom wall BW, four side walls SW, and one ceiling wall CW that constitute the folded box BX, and these are divided by the V groove VC. It is divided.
The bottom wall BW and the ceiling wall CW have a common shape, and in the present embodiment, are rectangular in plan view.
The four side walls SW are erected from the four sides of the bottom wall BW to form a rectangular frame (square cylinder) -shaped peripheral side frame.

The angle between two adjacent inclined surfaces via the deepest portion (valley bottom) of the V-groove VC is 90 degrees or more in a state where the laminated foam plate 10x is flat.
That is, the laminated foam board 10x is formed such that the portion where the V-groove VC is formed can be bent at an internal angle of 90 degrees or less.
Further, on the outer peripheral edge of the laminated foam board 10x, a chamfered portion CC which is C-chamfered so as to correspond to the inclined surface forming the V-groove VC is provided.
The folded box BX is formed by bending the laminated foam plate 10x by a V-groove VC, and the corner portion CP is provided along the V-groove VC.
Since the folded box BX of this embodiment has a rectangular parallelepiped shape as described above, four places along the four sides of the bottom wall BW, four places along the four sides of the ceiling wall CW, and four corners of the bottom wall BW and the ceiling There are a total of 12 corner parts CP at four places connecting with the four corners of the wall CW, but there are only five corner parts CP1 formed by the V groove VC, and the other corner parts CP2 are chamfered parts It is formed in the form which joins CC.

  In the folded box BX of the present embodiment, a sharp shape is given to the corner portion CP by the V groove, and an excellent appearance can be revealed by the covering sheet.

The peripheral side frame FB shown in FIG. 9 is a peripheral frame for a folding box provided with one or two or more corner portions, and more specifically, has an octagonal cylindrical shape.
The circumferential frame FB is combined with the container body CB and used as a folded box BX ′.
The circumferential frame FB is formed of a band-like laminated foam plate 10y provided with a V groove VC along a direction orthogonal to the longitudinal direction as shown in FIG. 8, and the laminated foam plate 10y is bent by the V groove VC. It is formed.
In FIG. 8, 90 ° V-grooves are formed at four places in two pairs, but the V-grooves do not have to be one pair and may be one or three or more.
Also, the angle of the V groove does not have to be 90 degrees, but may be another angle such as 45 degrees.
Furthermore, the V grooves need not be provided at all four places.
The circumferential frame FB of the present embodiment is common to the folded box BX in that the corner portion CP is provided along the V-shaped groove.

The container body CB includes a bottomed cylindrical main body portion CH having an upper opening and a flange portion FR extending outward from the upper opening edge of the main body portion CH.
The circumferential frame FB has an inside dimension slightly larger than the main body portion CH of the container body CB, and has an octagonal tubular shape slightly longer than the height of the main body portion CH.
Therefore, when the peripheral side frame FB is disposed in the state of being opened up and down, the peripheral portion frame of the container body CB can be contained by the upper end edge of the peripheral side frame FB while being capable of containing the main body portion CH of the container body CB. It is formed to be able to support from the lower side.

The peripheral side frame FB of the present embodiment has the octagonal cylindrical shape as described above, and has eight corner portions CP.
Similar to the folded box BX, the peripheral side frame FB of the present embodiment is such that a sharp shape is given to the corner portion CP by the V groove and an excellent aesthetic appearance can be revealed by the facing sheet.

  The use of the folding box BX and the folding box BX 'formed by the peripheral side frame FB is not particularly limited, but a food container for storing food etc. may be mentioned as a suitable use.

  In addition, the laminated foam board of this invention can be utilized for various uses other than such a container for foodstuffs, and this invention is not limited at all by the said illustration.

  EXAMPLES The present invention will next be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1
(Manufacturing method of polystyrene resin foam board)
100 parts by mass of polystyrene resin (manufactured by Toyo Styrene Co., Ltd., trade name "HRM-48N") in an extruder (φ 115 mm) on the upstream side of a tandem extruder in which two extruders are connected, and as a bubble regulator Talc kneaded polystyrene masterbatch (manufactured by Toyo Styrene Co., Ltd., trade name "DSM 1401A") 1.1 parts by mass, and as a colorant, pigmented polystyrene masterbatch manufactured by Sumika Color Co., Ltd. (Sumikawa Color Corp.) The mixed pellet which dry-blended with 2.5 mass parts of brand names "Brown SPSM-9A2933" and manufactured by Co., Ltd. is supplied, and the mixture is melted and kneaded, and the mixed butane (isobutane / normal butane = 65/35) as the foaming agent is polystyrene The melt is kneaded by further pressing into the extruder at a ratio of 3.60 parts by mass with respect to 100 parts by mass of the resin. The kneaded material is continuously fed to the downstream extruder (φ 150 mm), cooled by the downstream extruder so that the resin temperature becomes about 152 ° C., and extruded foam from the circular die attached to the tip of the extruder To form a tubular foam.
Thereafter, the cylindrical foam was sandwiched between pinch rolls and cooled while cooling to obtain a polystyrene resin foam board. The obtained polystyrene resin foam board has a total thickness of 5.0 mm, a density of 0.070 g / cm ³ , an average cell diameter (D _Z1 = 200 μm, D _Z2 = 320 μm, D _Z3 = 320 μm), and an arithmetic mean roughness (Ra) ) Was 23.5 μm. Respective values of L ^* , a ^* and b ^{* on} the surface of the obtained polystyrene resin foam plate were L ^* = 71.5, a ^* = + 12.6, b ^* = + 19.4.

(Production method of laminated products)
The surface of high quality paper was subjected to woodgrain printing to prepare a printing paper with a thickness of 70 μm.
Polyethylene resin (crystallinity: 45%, number average molecular weight (Mn): 35000, ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn): 7.6, melting point: 110 ° C.) The film was extruded from a T-die, and the extruded polyethylene resin film was laminated and integrated on the printing paper before cooling down, and a paper sheet layer (printing paper) and a resin film layer (polyethylene resin film) were provided. A covering sheet (laminated printing paper) was produced.
The average thickness of the resin film layer in the covering sheet was 15 μm.
An adhesive layer was formed on both sides of the polystyrene resin foam board using an ethylene-vinyl acetate copolymer aqueous emulsion adhesive as an adhesive.
The adhesive layer is formed using a coating roll was formed by applying an adhesive area 1 m ² per 25g of polystyrene resin foamed plate.
Thereafter, the covering sheet was laminated on both sides of the polystyrene resin foam plate using a pressure roll, to prepare a laminated foam plate.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 3.7 μm.
When each value of L ^* , a ^* , b ^* of the obtained laminated foam board was measured, the same value as each value of L ^* , a ^* , b ^* of the polystyrene resin foam board before laminating the covering sheet was measured. Met.

(Example 2)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 90 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 3.1 μm.

(Example 3)
It is carried out except that a talc kneading polystyrene masterbatch of a cell regulator is blended in 0.9 parts by mass with respect to 100 parts by mass of polystyrene resin, and mixed butane is added in 3.9 parts by mass with respect to 100 parts by mass of polystyrene resin. In the same manner as in Example 1, a polystyrene resin foam board was produced.
The obtained polystyrene resin foam board has a total thickness of 5.0 mm, a density of 0.070 g / cm ³ , an average cell diameter (D _Z1 = 350 μm, D _Z2 = 480 μm, D _Z3 = 480 μm), and an arithmetic average roughness (Ra) ) Was 30.0 μm.
Respective values of L ^* , a ^* and b ^{* on} the surface of the obtained polystyrene resin foam plate were L ^* = 70.0, a ^* = + 13.6, b ^* = + 19.3.
Thereafter, a laminated foam plate was produced in the same manner as in Example 1.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 4.0 μm.
When each value of L ^* , a ^* , b ^* of the obtained laminated foam board was measured, the same value as each value of L ^* , a ^* , b ^* of the polystyrene resin foam board before laminating the covering sheet was measured. Met.

(Example 4)
A laminated foam plate was produced in the same manner as in Example 3 except that a printing paper having a thickness of 50 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 4.3 μm.

(Example 5)
A laminated foam plate was produced in the same manner as in Example 3 except that a printing paper with a thickness of 30 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 4.5 μm.

(Example 6)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 100 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 2.8 μm.

(Example 7)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 110 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 2.6 μm.

(Example 8)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 120 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 2.4 μm.

(Example 9)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 140 μm was used.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 2.2 μm.

(Example 10)
The surface of wood free paper was subjected to woodgrain printing to prepare a printing paper 160 μm thick.
Polyethylene resin (crystallinity: 45%, number average molecular weight (Mn): 35000, ratio of weight average molecular weight (Mw) to number average molecular weight (Mn) (Mw / Mn): 7.6, melting point: 110 ° C.) The film was extruded from a T-die, and the extruded polyethylene resin film was laminated and integrated on the printing paper before cooling down.
Thereafter, it is passed through a roll having irregularities, and the resin film surface is embossed with a corrugated plate shape having a large number of ridges parallel to the flow direction (MD direction), and a paper sheet layer (printing paper) and a resin film layer A covering sheet (laminated printing paper) provided with (polyethylene resin film) was produced.
The average thickness of the resin film layer in the covering sheet was 20 μm.
Thereafter, a laminated foam plate was produced in the same manner as in Example 1.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 9.8 μm. The arithmetic mean roughness (Ra) in the MD direction was 18.2 μm, and the arithmetic mean roughness (Ra) in the TD direction was 1.4 μm.

(Comparative example 1)
A polystyrene-based resin foam board was produced in the same manner as in Example 1, and thereafter, a printed polystyrene film with a grain pattern of 120 μm in thickness was laminated by thermal lamination.
The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 0.35 μm.

(Comparative example 2)
In the same manner as in Example 1, a polystyrene resin foam board was produced, and then printing of wood grain patterns was performed directly on the surface of the foam board. The arithmetic mean roughness (Ra) of the surface on the printing side of the foam board was 23.5 μm.

(Comparative example 3)
A laminated foam plate was produced in the same manner as in Example 1 except that a printing paper having a thickness of 180 μm was used. The arithmetic mean roughness (Ra) of the surface on the film layer side of the obtained laminated foam board was 2.0 μm.

(Evaluation of laminated foam board)
With respect to a laminated foam plate having a glossiness of 2 or more and 9 or less, being provided with “moderate gloss and moderate unevenness”, and giving a calm wood feel, it was evaluated as “A”.
Although the surface glossiness is in the range of more than 9 and 15 or less and inferior to A, the laminated foam board having a calm texture is evaluated as "B".
Although the surface glossiness was in the range of more than 15 and 20 or less, it was inferior to B, and although it had a slight gloss, the laminated foam board within the allowable range was evaluated as “C”.
In addition, when the glossiness was out of the above range and the texture of the wood was impaired, it was evaluated as "D".
Further, in Comparative Example 2, unevenness of air bubbles was observed on the surface of the foam plate, and faint printing was also observed. Therefore, the texture of wood was not sufficiently expressed, and therefore, it was determined as D.
The above evaluation results are shown in the following table.

  Also from the above, according to the present invention, it is understood that the inhibition of the expression of the texture of the covering sheet in the laminated foam plate is inhibited.

Claims (8)

A laminated foam board comprising a polystyrene resin foam board and a covering sheet laminated on one side or both sides of the polystyrene resin foam board,
The covering sheet has a laminated structure,
The covering sheet includes a resin film layer provided on the most surface side, and a paper sheet layer in contact with the resin film layer from the inside,
The surface of the resin film layer is a laminated foam board having an arithmetic average roughness (Ra) of 2.2 μm to 9.8 μm and a gloss of 2 to 20. The resin film layer is formed of a polyolefin resin film,
The polyolefin resin contained in the polyolefin resin film has a crystallinity of 15% to 80%, a number average molecular weight (Mn) of 1 × 10 ^{4 to} 1 × 10 ⁵ , and a number average molecular weight The laminated foam board according to claim 1, wherein a ratio (Mw / Mn) of mass average molecular weight (Mw) to (Mn) is 2.0 or more and 15.0 or less.   The laminated foam board according to claim 2, wherein the polyolefin resin is a polyethylene resin having a melting point of 100 ° C to 120 ° C.   The laminated foam board according to any one of claims 1 to 3, wherein the average thickness of the paper sheet layer is 20 μm or more and 170 μm or less, and the average thickness of the resin film layer is 5 μm or more and 50 μm or less. The paper sheet layer is formed of a paper-like sheet,
The laminated foam board according to any one of claims 1 to 4, wherein the paper sheet is printed at least on the side in contact with the resin film layer.   The laminated foam board according to any one of claims 1 to 5, wherein the polystyrene resin foam board is colored by a coloring agent. It is a folding box provided with one or more corner portions,
It is formed of a laminated foam plate provided with a V groove, and the laminated foam plate is bent by the V groove,
The corner portion is provided along the V groove,
The folded box in which the said laminated foam board which has V groove | channel is a laminated foam board in any one of Claims 1-5. A circumferential frame for a box provided with one or more corner portions,
It is formed of a strip-like laminated foam plate provided with a V groove along a direction orthogonal to the longitudinal direction, and the laminated foam plate is bent by the V groove,
The corner portion is provided along the V groove,
The perimeter side frame for folding boxes which is a laminated foam board according to any one of claims 1 to 5, wherein the laminated foam board having a V groove is a laminated foam board according to any one of claims 1 to 5.