Tray-type paper container

Abstract

To provide a tray type paper container which is excellent in moldability and sealability while using only a paper base material.SOLUTION: A tray type paper container 10 is formed by molding a blank sheet (BL) prepared by punching a laminate 1 where thin paper 3 on which an adhesive 4 is coated and paperboard 2 subjected to necessary punching are laminated, wherein the blank sheet has a bottom face plate 5 having such a shape that a regular octagon is extended in the longitudinal direction and in the lateral direction, rectangular corner plates 6 are continuously provided in four non-extended sides of the bottom face plate, side face plates 7 having reverse trapezoidal shapes are continuously provided in other sides of the bottom face plate, edge pieces 8 are continuously provided in each of the side face plates, tips and edge pieces of each of the side face plates are molded so that the tips do not overlap each other in molding, the edge pieces have no step on the upper ends of the side face plates and form flat flange parts 9, when thickness of the paperboard is represented by A and thickness of the thin paper is represented by B, (A-B)≥150 μm and (A-3B)≤200 μm.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a tray-shaped paper container, and more particularly to a paper container that has a high paper content and is highly biodegradable in nature. [Background technology]

[0002] Tray- or box-shaped paper containers with waterproofing on the inside are widely used. The simplest type is a laminated body with waterproofing treatment such as laminating a synthetic resin film on the inside of cardboard, assembled into a box shape, and used as a container for storing lunch boxes with little liquid or snacks. These containers do not require significant water resistance and are assumed to be used horizontally, so there are also examples where a simple lid is used for the lid.

[0003] When using a tray-shaped paper container as a sealed container, it is necessary to consider not only the sealing property of the container body but also the sealing property of the lid. For this purpose, a method is adopted in which a horizontal flange is provided on the upper edge of the paper container and the lid is tightly sealed to this flange.

[0004] The tray container blank described in Patent Document 1 has side panels standing on the four sides of a rectangular bottom panel, with edge pieces extending from the tip of each side panel, so that the four edge pieces form a flange. The tray-shaped paper container with the flange formed thereon can be used as an airtight container by sealing it with a lid.

[0005] This invention solves the problem that tiny holes may form at the intersections of the side panels and the edge pieces, causing liquid to leak out, by providing a small protrusion on the edge of the tongue piece at the tip of the flange.

[0006] However, in a container assembled from the tray container blank described in Patent Document 1, it was unavoidable that a step would occur in the laminate at the flange due to its structure. If there was a step on the top surface of the flange, there was a risk of pinholes occurring at the step when the lid was sealed.

[0007] On the other hand, in recent years, the problem of environmental pollution, especially marine pollution, caused by plastic containers has become apparent. To address this problem, containers made of paper that are biodegradable even when discarded have been attracting attention.

[0008] Conventional paper containers use a fair amount of synthetic resin film material in addition to paper to ensure waterproofing and airtightness, and in some cases, the material is used up to the very limit of less than 50% that is required for certification as a paper container. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 3687396 Summary of the Invention [Problem to be solved by the invention]

[0010] The problem to be solved by the present invention is to propose a tray-type paper container which does not use any synthetic resin film material at all, but is made only from paper material, and which has excellent formability, sealability, designability and productivity. [Means for solving the problem]

[0011] As a means for solving the above problems, the invention described in claim 1 provides a tray-shaped paper container obtained by punching a blank sheet made by laminating a laminate of thin paper coated with a heat-sealable adhesive on its surface and a paperboard that has been punched in advance as required, and molding the blank sheet so that the adhesive layer is on the inner surface side of the container, The blank sheet has a bottom plate having a shape of a regular octagon stretched in the vertical and horizontal directions, and rectangular corner plates are connected to the four unstretched sides of the bottom plate via mountain fold lines, The other sides of the bottom panel are connected to inverted trapezoidal side panels via mountain folds, and edge pieces are connected to each side panel via valley folds. Between each corner board and the side board, and between each corner board and the edge piece, there is a portion where the paperboard is punched out so that only the tissue paper and the adhesive layer are present; When forming the panel, the tips and edges of each side panel are folded inside the corner panels so that the tips do not overlap. The edge piece is continuous with the upper end of the side panel, and forms a horizontal, stepless, flat flange portion that is parallel to the bottom surface and surrounds the periphery of the opening of the paper container; When the thickness of the paperboard is A (μm) and the thickness of the thin paper is B (μm), (AB)≧150μm and (A-3B)≦200μm This is a tray-type paper container characterized in that:

[0012] The tray-type paper container according to the present invention uses no synthetic resin films other than the paper material, and is therefore highly degradable even if it is discarded in nature.

[0013] In addition, the invention described in claim 2 satisfies the following conditions: (AB)≧200 μm and (A-3B)≦150 μm, where A (μm) is the thickness of the paperboard and B (μm) is the thickness of the thin paper. 2. The tray-type paper container according to claim 1, characterized in that:

[0014] The invention described in claim 3 is the tray-type paper container described in claim 1 or 2, characterized in that the adhesive is biodegradable or hydrolyzable in nature.

[0015] The invention described in claim 4 is the tray-type paper container described in any one of claims 1 to 3, characterized in that the adhesive is an aqueous dispersion of a modified polyolefin resin. Effect of the Invention

[0016] The tray-type paper container of the present invention does not use any synthetic resin films that are commonly used other than paper, so even if it is discarded in nature, it will decompose reliably in a relatively short period of time.

[0017] The tray-type paper container of the present invention satisfies the waterproof requirements of a container because the adhesive layer applied to the thin paper layer acts as a waterproof layer, and because the thin paper layer is present even in the areas where the paperboard has been cut out, the folded-in areas after molding also have excellent waterproofing.

[0018] The tray-type paper container according to the present invention is horizontal, has no steps, and has a flat flange portion, and therefore has excellent sealing properties when a lid is attached.

[0019] When the difference in thickness between the paperboard thickness A (μm) and the tissue paper thickness B (μm) is 150 μm or more and A-3B is 200 μm or less, as in the invention described in claim 1, the moldability is good, the step in the flange portion is reduced, and the sealing ability of the lid material is improved.

[0020] As described in claim 2, even better results can be obtained if the difference in thickness between the paperboard thickness A (μm) and the tissue paper thickness B (μm) is 200 μm or more and A-3B is 150 μm or less.

[0021] In the case where the adhesive is biodegradable or hydrolyzable in nature, as in the invention described in claim 3, the decomposition rate when discarded is further increased.

[0022] When the adhesive is an aqueous dispersion of a modified polyolefin resin as in the invention described in claim 4, the tray-type paper container has better airtightness, sealability and degradability. [Brief description of the drawings]

[0023] [Figure 1]FIG. 1 is a perspective view showing an example of a tray-type paper container according to the present invention. [Diagram 2] FIG. 2 is a schematic plan view of a blank sheet for the tray-type paper container shown in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing an example of the layer structure of a blank sheet of a tray-type paper container according to the present invention, and shows a schematic cross-section of a portion corresponding to the ZZ' cross-section in FIG. [Figure 4] FIG. 4 is a schematic cross-sectional view showing a state in which the blank sheet of FIG. 3 has been molded, and shows a schematic cross-section of a portion corresponding to the XY cross-section of FIG. [Diagram 5] FIG. 5 is a cross-sectional schematic diagram showing the layer structure of a blank sheet of a tray-type paper container described in the Examples, and shows a cross section of a portion corresponding to the ZZ' cross section in FIG. [Figure 6] FIG. 6 is a schematic cross-sectional view showing a state in which a blank sheet for a tray-type paper container described in the examples has been molded, and shows a schematic cross-section of a portion corresponding to the XY cross-section in FIG. [Figure 7] FIG. 7 is a cross-sectional explanatory diagram showing an example of a manufacturing method for a laminate used in a tray-type paper container according to the present invention, in which the hot platens of a flat press are open and a thin paper with an adhesive layer formed thereon is placed on a paperboard to which adhesive has been applied. [Figure 8] FIG. 8 is an explanatory cross-sectional view showing a state in which the heating platen is pressed from the state shown in FIG. [Figure 9] 9 to 12 show the process of producing a blank sheet for a tray-type paper container according to the present invention by a sheet-by-sheet method, and FIG. 9 is an explanatory plan view showing the state after the necessary punching has been applied to the paperboard layer. [Figure 10] FIG. 10 is an explanatory plan view showing a thin paper having an adhesive layer formed over the entire surface and cut to a predetermined size. [Figure 11] FIG. 11 is an explanatory plan view showing a laminate obtained by laminating the punched paperboard shown in FIG. 9 and the thin paper layer shown in FIG. [Figure 12]FIG. 12 is an explanatory plan view showing a state in which the laminate shown in FIG. 11 is punched out to form a blank sheet. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] Hereinafter, the tray-type paper container 10 according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a perspective view showing an example of a tray type paper container 10 according to the present invention. FIG. 2 is a schematic plan view of a blank sheet (BL) of the tray type paper container 10 shown in FIG. 1. FIG. 3 is a schematic cross-sectional view of the blank sheet (BL) of the tray type paper container according to the present invention, which shows a schematic cross-section of a portion corresponding to the ZZ' cross-section in FIG. 2. FIG. 4 is a schematic cross-sectional view showing a state in which the blank sheet in FIG. 3 has been molded, which shows a schematic cross-section of a portion corresponding to the XY cross-section in FIG. 1. The tray type paper container according to the present invention will be described below with reference to these drawings.

[0025] The tray-type paper container 10 of the present invention, as described in claim 1, is a tray-type paper container obtained by punching out a blank sheet (BL) made by laminating a laminate 1 made of thin paper 3 having a heat-sealable adhesive 4 applied to its surface and paperboard 2 having the necessary punchings 11 applied thereto in advance, and then molding the blank sheet (BL) so that the adhesive layer 4 is on the inner surface of the container.

[0026] In the example shown in Fig. 3, in order to laminate the paperboard layer 2 and the thin paper layer 3, an adhesive layer 4' is formed on the entire back surface of the thin paper layer 3 before lamination. In the example shown in Fig. 5, an adhesive layer 4' is formed on the back surface of the punched paperboard, and then laminated. In this way, the adhesive layer 4' for lamination may be formed on either the paperboard layer or the thin paper layer. Although not specifically shown, it may also be formed on both surfaces.

[0027] The adhesive layer 4' for lamination is preferably biodegradable or hydrolyzable in nature. The tray-type paper container according to the present invention does not use any synthetic resin film material that is generally used, and is made only of paper material, so even if a vinyl acetate adhesive, an ethylene vinyl acetate copolymer (EVA) adhesive, an acrylic emulsion adhesive, or the like that is generally used as an adhesive is used, it will easily decompose in nature. However, if a biodegradable or hydrolyzable adhesive is used as the adhesive 4', the decomposition will be further accelerated, and the burden on nature will be reduced.

[0028] The adhesive layer 4 applied to the surface of the thin paper 3 must have heat sealability in order to form the paper container. Examples of such adhesives include the vinyl acetate adhesives, ethylene vinyl acetate copolymer (EVA) adhesives, and acrylic emulsion adhesives described above, with aqueous dispersions of modified polyolefin resins being particularly suitable.

[0029] The adhesive 4 applied to the entire surface of the thin paper 3 and the adhesive 4' used to laminate the thin paper 3 and the paperboard 2 may be the same adhesive or different adhesives.

[0030] The blank sheet (BL) used in the tray-type paper container according to the present invention has a bottom plate 5 in the shape of a regular octagon stretched vertically and horizontally, as shown in Fig. 2. Rectangular corner plates 6, 6, 6, 6 are connected to the four unstretched sides of the bottom plate 5 via mountain fold lines e, f, g, h, respectively.

[0031] Inverted trapezoidal side panels 7, 7, 7, 7 are connected to the other sides of the bottom panel 5 via mountain fold lines a, b, c, d, respectively, and edge pieces 8, 8, 8, 8 are connected to each side panel via valley fold lines i, j, k, l.

[0032] Between each corner plate 6 and side plate 7, and between each corner plate 6 and edge piece 8, there are portions 11 where the paperboard layer 2 has been punched out so that only the thin paper layer 3 and the adhesive layer 4 are present.

[0033] The paperboard layer 2, which is usually the outer side of the container, is printed with markings and becomes the surface side of the laminate 1. Therefore, the fold lines that form a mountain on the paperboard layer 2 side are mountain fold lines, and the fold lines that form a valley on the paperboard layer 2 side are valley fold lines. In Fig. 2, the mountain fold lines are shown as dotted lines, and the valley fold lines are shown as dashed lines. Therefore, Fig. 2 shows the blank sheet (BL) as seen from the surface side.

[0034] During molding, the tip and edge piece 8 of each side panel 7 are folded inside each corner panel 6 and molded so that the tips do not overlap, and the edge piece 8 is continuous with the upper end of the side panel 7 and forms a horizontal, step-free, flat flange portion 9 that is parallel to the bottom surface 5 and surrounds the opening of the paper container.

[0035] After examining various combinations of the paperboard layer 2 and thin paper layer 3 for such tray-type paper containers, it was found that when the thickness of the paperboard layer 2 is A (μm) and the thickness of the thin paper layer 3 is B (μm), it is important for the molding suitability of the paper tray and the step of the flange portion, i.e., the sealing ability of the lid material, that (AB) ≧ 150 μm and (A-3B) ≦ 200 μm.

[0036] It has also been found that, in the relationship between A (μm) and B (μm), when (AB)≧200 μm and (A-3B)≦150 μm, even better results can be obtained.

[0037] Next, a method for manufacturing the tray type paper container 10 according to the present invention will be described. Fig. 7 is a cross-sectional explanatory view showing an example of a method for manufacturing the laminate 1 used in the tray type paper container 10 according to the present invention, and is a cross-sectional explanatory view showing a state in which the thin paper 3 on which the adhesive layer 4 has been formed is placed on the paperboard 2 on which the adhesive 4' has been applied, with the hot platen 21 of the flat press machine 20 in an open state. Fig. 8 is a cross-sectional explanatory view showing a state in which the hot platen 21 is pressed from the state shown in Fig. 7.

[0038] In Figures 7 and 8, only one set is pressed, but in some cases multiple sets are stacked with release film between them and then pressed to bond them. Also, cushions and release films are omitted from the figures.

[0039] The laminate 1 can be produced by a sheet-by-sheet method as shown in Figures 7 and 8, or it can be produced continuously by a winding method (not shown). The winding method is suitable for mass production, while the sheet-by-sheet method is suitable for small-lot production of a wide variety of products.

[0040] 9 to 12 show the process of producing a blank sheet (BL) for a tray type paper container 10 according to the present invention by a sheet-by-sheet method, and FIG. 9 is an explanatory plan view showing the state in which the necessary punching 11 has been applied to the paperboard layer 2. FIG. 10 is an explanatory plan view showing the thin paper 3 having an adhesive layer 4 formed on the entire surface and cut to a predetermined size. FIG. 11 is an explanatory plan view showing the state in which the punched paperboard 2 shown in FIG. 9 and the thin paper 3 shown in FIG. 10 are bonded together to form a laminate 1. FIG. 12 is an explanatory plan view showing the state in which the laminate 1 shown in FIG. 11 has been punched to form a blank sheet (BL). The tray type paper container 10 according to the present invention will be specifically described below based on examples. EXAMPLES

[0041] <Example 1> Paperboard cut to the specified size (Mitsubishi Paper Mills, Pearl Card, basis weight 400g / m 2 After punching out the necessary parts, the paper was pressed into thin paper (Nippon Paper Industries, bleached kraft paper, 100 g / m2 basis weight) using a flat press. 2 A laminate was made by laminating a thin paper with a board (150 μm thick). An adhesive (aqueous dispersion of modified polyethylene resin, Arrowbase, manufactured by Unitika Ltd.) was applied to the entire surface of the thin paper in advance and dried, and the same adhesive was applied to the bonding surface of the board except for the punched-out parts, and the two were laminated.

[0042] If the thickness of the paperboard is A (μm) and the thickness of the tissue paper is B (μm), then AB = 300 μm and A-3 × B = 0 μm.

[0043] The laminate was punched out to produce a blank sheet as shown in Fig. 2. Fig. 5 is a cross-sectional schematic diagram showing the layer structure of the laminate in the ZZ' cross section of Fig. 2. Next, this blank sheet was molded under heat and pressure to produce a tray-type paper container having the shape shown in Fig. 1. Fig. 6 is a cross-sectional schematic diagram showing the XY cross section of this paper container in Fig. 1.

[0044] This tray-type paper container was evaluated for its moldability (wrinkles), unevenness at the flange, and leakage after sealing with the lid.

[0045] <Example 2> Thin paper with a thickness of 100 μm (Nippon Paper Industries, bleached kraft paper, basis weight 80 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 350 μm, A-3 × B = 150 μm, and evaluation was performed in the same manner.

[0046] <Example 3> The paperboard is 350 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 300 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that a paper sheet having a thickness of 100 μm and a thickness of 100 μm and a thickness of 100 μm were used, and evaluated in the same manner.

[0047] <Example 4> The paperboard is 350 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 300 g / m 2 ) was used, and a thin paper with a thickness of 100 μm (Nippon Paper Industries, bleached kraft paper, basis weight 80 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 250 μm, A-3 × B = 50 μm, and was evaluated in the same manner.

[0048] <Example 5> The paperboard is 350 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 300 g / m 2 ) was used, and a thin paper of 80 μm thickness (Nippon Paper Industries, bleached kraft paper, 60 g / m2) was used. 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 270 μm, A-3 × B = 110 μm, and was evaluated in the same manner.

[0049] <Example 6> The paperboard is 350 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 300 g / m 2 ) was used, and a thin paper with a thickness of 60 μm (Nippon Paper Industries, bleached kraft paper, grammage 50 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A-3×B was used, and evaluated in the same manner. AB=290 μm, A-3×B=170 μm.

[0050] <Example 7> The paperboard is 310 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 270 g / m 2 ) was used, and a thin paper with a thickness of 100 μm (Nippon Paper Industries, bleached kraft paper, basis weight 80 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 210 μm, A-3 × B = 10 μm, and was evaluated in the same manner.

[0051] <Example 8> The paperboard is 310 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 270 g / m 2 ) was used, and a thin paper of 80 μm thickness (Nippon Paper Industries, bleached kraft paper, 60 g / m2) was used. 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 230 μm, A-3 × B = 70 μm, and was evaluated in the same manner.

[0052] <Example 9> The paperboard is 310 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 270 g / m 2) was used, and a thin paper with a thickness of 60 μm (Nippon Paper Industries, bleached kraft paper, grammage 50 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 250 μm, A-3 × B = 130 μm, and evaluation was performed in the same manner.

[0053] <Example 10> The paperboard is 280 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 240 g / m 2 ) was used, and a thin paper of 80 μm thickness (Nippon Paper Industries, bleached kraft paper, 60 g / m2) was used. 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 200 μm, A-3 × B = 40 μm, and was evaluated in the same manner.

[0054] <Example 11> The paperboard is 280 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 240 g / m 2 ) was used, and a thin paper with a thickness of 60 μm (Nippon Paper Industries, bleached kraft paper, grammage 50 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 220 μm, A-3 × B = 100 μm, and was evaluated in the same manner.

[0055] Example 12: Paperboard with a thickness of 260 μm (Mitsubishi Paper Mills, Pearl Card, basis weight 220 g / m 2 ) was used, and a thin paper of 80 μm thickness (Nippon Paper Industries, bleached kraft paper, 60 g / m2) was used. 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 180 μm, A-3 × B = 20 μm, and was evaluated in the same manner.

[0056] <Example 13> The paperboard is 260 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 220 g / m 2 ) was used, and a thin paper with a thickness of 60 μm (Nippon Paper Industries, bleached kraft paper, grammage 50 g / m 2A tray-type paper container was produced in the same manner as in Example 1, except that A B = 200 μm, A-3 × B = 80 μm, and was evaluated in the same manner.

[0057] <Comparative Example 1> Thin paper 60 μm thick (Nippon Paper Industries, bleached kraft paper, grammage 50 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 390 μm, A-3 × B = 270 μm, and was evaluated in the same manner.

[0058] <Comparative Example 2> The paperboard is 280 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 240 g / m 2 ) was used, and a thin paper with a thickness of 150 μm (Nippon Paper Industries, bleached kraft paper, basis weight 100 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 130 μm, A-3 × B = -170 μm, and evaluated in the same manner.

[0059] <Comparative Example 3> The paperboard is 260 μm thick (Mitsubishi Paper Mills, Pearl Card, basis weight 220 g / m 2 ) was used, and a thin paper with a thickness of 150 μm (Nippon Paper Industries, bleached kraft paper, basis weight 100 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 110 μm, A-3 × B = -190 μm, and evaluated in the same manner.

[0060] <Comparative Example 4> The paperboard is 180 μm thick (Mitsubishi Paper Mills, Pearl Card, 160 g / m 2 ) The thin paper used was 150 μm thick (Nippon Paper Industries, bleached kraft paper, 100 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that a paper sheet having a thickness of 100 mm or less was used, and was evaluated in the same manner. AB=30 μm, A-3×B=−270 μm.

[0061] <Comparative Example 5> The paperboard is 180 μm thick (Mitsubishi Paper Mills, Pearl Card, 160 g / m 2 ) was used, and a thin paper with a thickness of 100 μm (Nippon Paper Industries, bleached kraft paper, basis weight 80 g / m 2 A tray-type paper container was produced in the same manner as in Example 1, except that A B = 80 μm, A-3 × B = -120 μm, and was evaluated in the same manner.

[0062] <Comparative Example 6> The paperboard is 180 μm thick (Mitsubishi Paper Mills, Pearl Card, 160 g / m 2 ) was used, and a thin paper of 80 μm thickness (Nippon Paper Industries, bleached kraft paper, 60 g / m2) was used. 2 A tray-type paper container was produced in the same manner as in Example 1, except that AB was used, and evaluated in the same manner. AB=100 μm, A-3×B=−60 μm.

[0063] The above results are summarized in Table 1.

[0064] [Table 1]

[0065] The results in Table 1 show that the tray-type paper container according to the present invention has excellent moldability, has few steps in the flange portion, and causes no leakage after sealing with the lid. [Explanation of symbols]

[0066] 1. Laminate 2. Paperboard layer 3...Thin paper layer 4, 4´...adhesive layer BL...Blank sheet 5...Bottom plate 6 Corner plate 7...Side plate 8. Edge piece 9. Flange section 10. Tray-type paper container 11 Punching section a~l···fold line 20. Flat press machine 21...hot plate

Claims

1. A tray-shaped paper container is made by punching a blank sheet made by laminating a laminate of thin paper coated with a heat-sealable adhesive on its surface and a paperboard that has been punched in advance as required, and molding the blank sheet so that the adhesive layer is on the inner surface side of the container, The blank sheet has a bottom plate having a shape of a regular octagon stretched in the vertical and horizontal directions, and rectangular corner plates are connected to the four unstretched sides of the bottom plate via mountain fold lines, The other sides of the bottom panel are connected to inverted trapezoidal side panels via mountain folds, and edge pieces are connected to each side panel via valley folds. Between each corner board and the side board, and between each corner board and the edge piece, there is a portion where the paperboard is punched out so that only the tissue paper and the adhesive layer are present; When forming the panel, the tips and edges of each side panel are folded inside the corner panels so that the tips do not overlap. The edge piece is continuous with the upper end of the side panel, and forms a horizontal, stepless, flat flange portion that is parallel to the bottom surface and surrounds the periphery of the opening of the paper container; When the thickness of the paperboard is A (μm) and the thickness of the thin paper is B (μm), (A-B) ≧ 150 μm and (A-3B) ≦ 200 μm A tray-type paper container characterized in that:

2. When the thickness of the paperboard is A (μm) and the thickness of the thin paper is B (μm), (A-B)≧200 μm and (A-3B)≦150 μm 2. The tray-type paper container according to claim 1,

3. 3. The tray-type paper container according to claim 1, wherein the adhesive is biodegradable or hydrolyzable in nature.

4. 4. The tray-type paper container according to claim 1, wherein the adhesive is an aqueous dispersion of a modified polyolefin resin.

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