JP7507472B2 - Paper container with lid - Google Patents

Description

This invention relates to a paper container with a lid.

At convenience stores, fast food restaurants, food stalls, and other eateries, when food and drink items such as prepared dishes, rice bowls, salads, noodles, and soups are sold as take-out items, the appropriate food and drink items are provided in disposable beverage containers made of synthetic resin such as PET resin. Take-out containers are of as simple a structure as possible as they are disposable containers, and are generally molded products made of synthetic resin sheets with a lid fitting structure in which a lid is removably fitted into the upper opening of the container body to prevent the contents from spilling when the purchaser carries the product.

For example, a known food container of this type is an internally fitted container with a lid, in which the fitting portion of the lid is tightly fitted against the inner wall of the upper opening of the heat-resistant resin container body (see, for example, Patent Document 1). In an internally fitted container with a lid, the inner wall of the upper opening of the resin container body is formed in an inverted taper shape, and the fitting portion of the lid is formed in a protruding shape that corresponds to the inverted taper inner wall, so that the protruding fitting portion of the lid fits deeply into the inverted taper inner wall of the container, thereby achieving tight contact between the two.

For food products that contain a lot of liquid (soup), such as soups and noodles, paper container bodies have traditionally been used. In recent years, the problem of plastic waste, such as marine plastic litter, has attracted attention, and there is a trend to refrain from manufacturing and using synthetic resin products in order to reduce the environmental impact. Therefore, even for this type of food container, it has become popular to make the container body out of paper.

In paper containers, thick cardboard is rolled into a circular shape to form the body of the container, the upper part of which is rolled outward to form the rolled opening edge, and the lower part is folded inward to join with the bottom plate to form the bottom. With this type of paper container body, the inner peripheral wall surface of the upper opening is a smooth surface of the cardboard, and special molding for internal fitting such as an inverted tapered shape like the resin containers mentioned above is not possible. Therefore, when closing the lid, the peripheral wall part extending downward from the outer peripheral edge of the lid body is attached from the outside to the rolled opening edge of the container body, and the peripheral wall part of the lid body is engaged with the underside of the rolled edge of the container body by external fitting.

However, because paper container bodies are made by forming fan-shaped or band-shaped paperboard into a cylindrical shape, it is difficult to mold them precisely like synthetic resins. In addition, when forming the paperboard into a cylindrical shape, both ends of the paperboard are overlapped and glued together, so a slight step is formed in the glued parts of the paperboard. When the shapes of the mating parts of the container body and lid are matched, the molding precision affects the adhesion performance of the mating parts. Therefore, when a lid is fitted to a paper container body, which is difficult to mold precisely, there is a problem that containers are likely to be produced that do not have sufficient adhesion between the container body and the lid.

JP 2019-127301 A

The present invention has been made in consideration of these points, and provides a paper container with a lid that can reduce the effect of molding precision of the container body when closing the lid on the container body, thereby improving adhesion between the container body and the lid.

That is, the invention of claim 1 comprises a container body made of paper or a material mainly made of paper or plant fiber, having a cylindrical shape or an inverted truncated cone shape with an upper opening, and an inner peripheral wall portion 24a near the edge of the upper opening is formed with a groove-like fitting portion 50 that runs parallel to the upper opening; a cover surface portion that covers the upper opening of the container body; and a hanging portion that is provided on the outer periphery of the cover surface portion so as to enter the upper opening of the container body and abut or come close to the inner peripheral wall portion, and a convex fitting portion is formed on the outer periphery of the hanging portion, and a diameter D1 at the convex fitting portion of the cover body is equal to a diameter D2 at the groove-like fitting portion of the container body. (the distance between the upper inner wall portion 24c of the groove-shaped fitting portion 50, which is the boundary portion between the groove-shaped fitting portion 50 and the inner wall portion 24a), and the protruding length L1 of the convex fitting portion is configured to be greater than or equal to the depth L2 of the groove-shaped fitting portion, so that when the lid is closed, the convex fitting portion is pressed against the groove-shaped fitting portion to fit therein.

The invention of claim 2 relates to the paper container with lid described in claim 1, in which the lid is made of a synthetic resin sheet molded product.

The invention of claim 3 relates to the paper container with lid described in claim 1 or 2, in which a heat insulating portion is formed on the outside of the container body.

The invention of claim 4 relates to the paper container with lid described in claim 3, in which the heat insulating portion is formed by wrapping an insulating paper sleeve around the container.

The invention of claim 5 relates to the lidded paper container of claim 4, in which the insulating paper sleeve is embossed paper.

According to the invention of claim 1, the paper container with lid comprises a container body made of paper or a material mainly made of paper or plant fiber, having a cylindrical shape or an inverted truncated cone shape with an upper opening, and an inner peripheral wall portion 24a near the edge of the upper opening is formed with a groove-like fitting portion 50 that runs parallel to the upper opening; a lid body having a lid surface portion that covers the upper opening of the container body, and a hanging portion that is provided on the outer periphery of the lid surface portion so as to enter the upper opening of the container body and abut or come close to the inner peripheral wall portion, and a convex fitting portion is formed on the outer periphery of the hanging portion, and a diameter D1 of the convex fitting portion of the lid body is smaller than a diameter D2 of the groove-like fitting portion of the container body. Since the protruding length L1 of the convex ridge fitting portion is greater than the depth L2 of the concave groove-shaped fitting portion (the distance between the upper inner wall portion 24c of the concave groove-shaped fitting portion 50, which is the boundary portion between the concave groove-shaped fitting portion 50 and the inner wall portion 24a) and the protruding length L1 of the convex ridge fitting portion is greater than or equal to the depth L2 of the concave groove-shaped fitting portion, the convex ridge fitting portion is pressed against the concave groove-shaped fitting portion when the lid is closed, thereby suppressing the effect of the molding accuracy of the container body, improving the adhesion between the container body and the lid, allowing the lid to be properly closed by internal fit alone, and effectively suppressing leakage of the contents.

According to the invention of claim 2, the paper container with lid is the invention of claim 1, in which the lid is made of a synthetic resin sheet molded product, so not only is there a large degree of freedom in the shape of the lid and it is easy to mold it precisely, but deformation of the convex fitting part of the synthetic resin sheet lid can be prevented by the partial deformability of the groove-like fitting part of the container body and the overall rigidity of the container body, ensuring effective adhesion.

According to the paper container with lid of the invention of claim 3, in the invention of claims 1 or 2, a heat insulating part is formed on the outside of the container body, so that the effect of heat can be mitigated and the container can be easily held.

According to the paper container with lid of the invention of claim 4, in the invention of claim 3, the heat insulating part is formed by wrapping a heat insulating paper sleeve around it, so it can be manufactured cheaply and easily, and is suitable for use as a disposable container.

According to the paper container with lid of the invention of claim 5, in the invention of claim 4, the insulating paper sleeve is embossed paper, so that the strength can be improved as well as the insulating effect.

1 is a schematic cross-sectional view of a lidded paper container according to one embodiment of the present invention. 1 is a schematic cross-sectional view of the vicinity of the edge of the top opening of a lidded paper container when the lid is open. 1 is a schematic cross-sectional view of the vicinity of the edge of the top opening of a lidded paper container when the lid is closed. FIG. 1 is a plan view of a lid having steam holes consisting of multiple long holes. FIG. 1 is a plan view of a lid having a steam hole formed by a tongue-shaped opening. FIG. 1 is a schematic cross-sectional view of the vicinity of the edge of the upper opening when the lid is pressed into a paper container with a lid.

The paper container with lid 10 according to one embodiment of the present invention shown in Figure 1 is a container for mainly storing food and drink, and comprises a container body 20 and a lid body 40. Examples of food and drink that can be stored in the container include boxed lunches such as oyakodon (chicken and egg on rice), gyudon (beef on rice), katsudon (pork cutlet on rice), and Chinese rice bowls, noodles such as ramen, udon, and soba, and cooked foods and instant foods such as soups such as corn soup, Chinese soup, miso soup, and soup vermicelli.

The lidded paper container 10 containing food and drink is used, for example, at stores such as convenience stores, supermarkets, department stores, restaurants, and food stalls, as well as for serving buffets, catering, takeout, and home delivery services. The main anticipated use is as a one-way or disposable disposable container that is used only once. Disposable containers are convenient for hygienic management of food and drink.

The container body 20 is made of paper or a material mainly made of paper or plant fiber, and is a cylindrical or inverted truncated cone-shaped container with an upper opening 21. The paper material that constitutes the container body 20 is preferable from the viewpoint of reducing the environmental load, and has excellent heat resistance, so it can be suitably used as a material for food and beverage containers. In addition, in the container body 20, a resin film such as a polyethylene resin, a polystyrene resin, a polypropylene resin, or a polyester resin may be laminated on the inside or both the inside and outside of the container to impart water resistance, heat resistance, oil resistance, etc. The thickness of the laminated resin film is not particularly limited, but is, for example, about 15 to 40 μm. In the embodiment, a heat-resistant PET resin film with a thickness of 33 μm is laminated.

Container body 20 shown in FIG. 1 has an upper opening 21 with an outwardly rolled edge 22, and a container body 24 is connected in an inversely tapered manner from the upper opening 21 to the container bottom 23, forming a substantially inverted truncated cone shape. Container body 20 is manufactured by a known method for manufacturing paper containers. For example, a fan-shaped or band-shaped body paperboard 24s is formed into a cylindrical shape to form container body 24, the upper part of body paperboard 24s is wrapped outward to form upper opening 21 with outwardly rolled edge 22, and container bottom 23 is formed by bonding and joining lower folded part 29 of body paperboard 24s to folded part 28 of circular bottom paperboard 23s to form container body 23, thereby obtaining container body 20. The container body 20 may be formed into a cylindrical shape with the container body 24 being substantially vertical by making the upper opening 21 and the container bottom 23 substantially the same diameter, or, as in the embodiment, into an inverted truncated cone shape with the container body 24 tapered by making the upper opening 21 larger in diameter than the container bottom 23. The container body 20 having an inverted truncated cone shape is convenient for stacking.

As shown in Figs. 1 and 2, the container body 20 has a groove-shaped fitting portion 50 formed on the inner peripheral wall portion 24a of the container body 24 near the outer peripheral edge portion 22 of the upper opening 21, which runs parallel to the outer peripheral edge portion 22 of the upper opening 21. The groove-shaped fitting portion 50 is a portion that allows the lid body 40 described below to be fitted inside. The groove-shaped fitting portion 50 is formed by pressing a predetermined position of the container body 24 from the inside of the container body 20 using an appropriate pressing device such as a known groove forming device or jig after molding the container body 20, so that as shown in the figure, a part of the container body 24 is pushed out from the inside to the outside. Therefore, an outer peripheral convex portion 25 is formed around the entire circumference at a position corresponding to the groove-shaped fitting portion 50 on the outer peripheral wall portion 24b of the container body 24.

It is preferable to form a heat insulating section 30 on the outside of the container body 20. The heat insulating section 30 is a section for preventing the temperature of the contents inside the container body 20 from being transferred to the user's hands when the user holds the container body 20. For example, if the contents are food or drink that can reach relatively high temperatures, such as noodles or soup, the container may be difficult to hold because of the heat, but the heat insulating section 30 reduces the conduction of heat, making it easier to hold. Also, if the contents are food or drink that is relatively cold, condensation may form on the container body 24, but the heat insulating section 30 can suppress this condensation, allowing the user to hold the container without getting their hands wet with condensation.

The heat insulating section 30 can be formed by a known container heat insulating structure such as embossing the container body 24 of the container body 20, uneven processing on the outer periphery of the container body 20 with heat insulating ink, or wrapping a sleeve. For example, the heat insulating section 30 can be formed by wrapping a heat insulating paper sleeve 31, which is suitable for use in disposable containers. The heat insulating paper sleeve 31 can be manufactured cheaply and easily, and if the heat insulating paper sleeve 31 is made of embossed paper, the heat insulating effect and strength can be improved. The heat insulating paper sleeve 31 can be directly bonded to the outside of the container body 20, but as shown in Figures 1 and 2, by bonding the upper side to the outer periphery ridge portion 25 of the container body 24, an air layer 35 can be formed between the container body 20 and the heat insulating effect can be improved.

The lid 40 is a member that covers the upper opening 21 of the container body 20, and has a lid surface portion 41 and a hanging portion 43 as shown in Figures 1 to 4. The lid 40 is preferably made of synthetic resin, as this allows for a large degree of freedom in the shape of the lid and allows for easy precision molding. For example, a molded product made of a synthetic resin sheet is preferable in terms of mass production and economy. Examples of synthetic resin sheets that make up the lid 40 include sheets of thermoplastic resins such as polyethylene, polypropylene, polystyrene, and polyethylene terephthalate, as well as thermoplastic resin sheets of biodegradable resins such as polylactic acid. The synthetic resin sheets are formed into various shapes, including those shown in the figures, by vacuum molding.

The lid surface portion 41 is a portion that covers the upper opening 21 of the container body 20, and a lid flange portion 42 is formed on the outer periphery via a hanging portion 43. The lid flange portion 42 is a portion that abuts against the edge portion of the upper opening 21 of the container body 20 over the entire circumference, and prevents the lid body 40 from excessively entering or dropping into the container body 20 when the lid is closed. The shape of the lid flange portion 42 is not particularly limited as long as it can abut against the edge portion of the upper opening 21 of the container body 20. For example, since the upper opening 21 is formed with an outer rolled edge portion 22 and the upper side of the edge is curved, it is preferable to make the lid flange portion 42a curved in a shape corresponding to the outer rolled edge portion 22, as shown in Figures 2 and 3. The curved lid flange portion 42a improves the sense of moderation when the lid body 40 is closed. The lid flange portion 42 may be knurled as necessary.

If necessary, the lid surface portion 41 may be provided with a steam hole 45 for discharging steam, as shown in Figures 5 and 6. The shape of the steam hole 45 is not particularly limited as long as it can properly discharge steam, and it may be configured with an appropriate shape such as a small hole, a long hole, or a tongue-shaped opening.

For example, FIG. 5 is a plan view of the lid body 40A having a steam hole 45a consisting of a plurality of long holes. The steam hole 45a is formed in a concave surface portion 46 formed at an appropriate position of the lid surface portion 41, and constitutes a group of long holes consisting of a plurality of long holes. The steam hole 45a consisting of a plurality of long holes is preferably formed, for example, by laser processing using irradiation of a laser beam. The laser processing can form the steam hole 45a simply, quickly, and accurately. The size of the long hole is not particularly limited as long as it is possible to appropriately discharge steam inside the container body 20. For example, when the steam hole 45a is a group of long holes, the appropriate conditions for discharging steam and preventing foreign matter from entering the container body 20 are a width of 0.15 to 1.0 mm, a length of 1 to 12 mm, and a total opening area of 0.3 to ¹⁰⁰ mm2, which allows steam to be appropriately discharged and makes it possible to prevent foreign matter from entering the container body 20 without providing a member for covering the steam hole 45a to prevent foreign matter from entering the container body 20. Although not shown, fine holes (a group of fine holes) may be formed instead of the long holes (a group of long holes). Appropriate conditions for the fine holes (a group of fine holes) to discharge steam and suppress the ingress of foreign matter are a diameter of 0.15 to 1.0 mm, preferably 0.15 to 0.59 mm, a number of 8 to 1000, and a total opening area of 0.25 to ¹⁰⁰ mm2.

Figure 6 is a plan view of the lid 40B having a steam hole 45b consisting of a tongue-shaped opening. The steam hole 45b is formed by a known processing device such as a punching blade. The steam hole 45b consisting of a tongue-shaped opening is pushed up and opened by steam generated inside the container, allowing the steam to be discharged. The steam hole 45b consisting of a tongue-shaped opening can be formed inexpensively and easily. The lid 40B having this steam hole 45b is preferably used when the entire container 10 is covered with a film or the like when packaging a product.

As shown in Figures 2 and 3, the hanging portion 43 is a portion that is interposed between the lid surface portion 41 and the lid flange portion 42 and enters the upper opening 21 of the container body 20, and is provided so as to abut or be close to the inner peripheral wall portion 24a near the upper opening 21 of the container body 20 when the lid is closed. The shape of the hanging portion 43 is appropriate, such as being perpendicular to the lid surface portion 41 or inclined along the inner peripheral wall portion 24a of the container body 20. In addition, the lid flange portion 42 extends outward from the upper end of this hanging portion 43.

The hanging portion 43 has a protruding fitting portion 55 formed on the outer periphery 43a, which fits into the groove-shaped fitting portion 50 of the container body 20 when the lid is closed. The protruding fitting portion 55 is a portion that fits into the groove-shaped fitting portion 50 of the container body 20 when the lid is closed, thereby enabling the lid body 40 to maintain its internal fit.

Conventionally, it has been difficult to close a lid on a paper container body by simply fitting it inside. This is because, when the container body is made of paper, the inner wall portion near the top opening must be a substantially flat surface in normal manufacturing, and it is structurally difficult to fit the lid inside this flat inner surface. In other words, in order to close a lid on a paper container body by simply fitting it inside, it is necessary to hold the hanging part of the lid in a state in which it is pressed against the substantially flat inner wall portion of the container body. However, if the inner wall portion is a flat surface, the pressed part is slippery, and the pressed state is easily released by slight vibration or impact, causing the lid to come off. In addition, when manufacturing a paper container body, it is not possible to precisely mold it like synthetic resin, and because paper has the unique deformability, it is not possible to maintain the internal fit of the lid like synthetic resin. Therefore, if the lid is closed by fitting the hanging portion of the lid into the container body, it is necessary to add a special structure other than the fitting, such as fixing the container body and the lid using other auxiliary fixing means such as adhesive tape.

Therefore, in the paper container 10 of the present invention, a groove-shaped fitting portion 50 is formed on the inner wall portion 24a of the container body 20, and a protruding fitting portion 55 is formed on the outer periphery 43a of the hanging portion 43 of the lid body 40, making it possible to close the lid by internal fitting alone, which was not possible with conventional paper containers. Here, the preferred conditions for the groove-shaped fitting portion 50 and the protruding fitting portion 55 are described in detail below.

First, the groove-shaped fitting portion 50 may be located in any position as long as it is located near the upper opening 21, which is above the top of the food or drink contained in the container body 20. For example, the groove-shaped fitting portion 50 is located at a position where the distance from the upper opening 21 to the top of the fitting portion 50 is about 3 to 10 mm. If the fitting portion 50 is too close to the upper opening 21, the lid 40 may not be able to fit properly inside, and if it is too far from the upper opening 21, there is a problem that the lid 40 will penetrate more than necessary into the container body 20.

The ridge-shaped fitting portion 55 provided on the hanging portion 43 of the lid 40 is appropriately set according to the position of the groove-shaped fitting portion 50. If the lid 40 is made of a synthetic resin sheet molded product, the shape of the lid 40 can be freely chosen and precise molding can be easily performed. In addition, when the internal fitting structure of this invention is used, effective adhesion can be ensured even for a paper container body 20, which is difficult to mold precisely, by the partial deformability of the groove-shaped fitting portion 50 of the container body 20 and the overall rigidity of the container body 20, even when the ridge-shaped fitting portion 55 of the synthetic resin sheet lid 40 is deformed.

That is, as mentioned above, the container body 20 is capable of partial deformation due to the structure of the resin fibers, but has the characteristic that the surface as a whole is relatively rigid and the amount of deformation is small, while the synthetic resin sheet lid 40 is characterized by its flexibility, which means that it is more likely to deform overall than partial deformation. The difference between these two characteristics is that in the case of the conventional external fitting described above, the lid separates from the container body, resulting in a defect in the fitting becoming loose, but in the case of the internal fitting of the present invention, on the other hand, the partial deformability of the groove-like fitting portion 50 of the container body 20 and the overall rigidity of the container body firmly accept the deformation of the ridge fitting portion 55 of the lid, which has the advantage of ensuring effective adhesion.

In addition, when forming a paper container body into a cylindrical shape, a slight step occurs at the adhesive portion where both ends of the paperboard are overlapped, but this slight step affects the molding precision of the container body, and so it is a place where adhesion is likely to be insufficient with conventional external fitting. With the internal fitting of the present invention, the effects of molding precision of the container body can be mitigated, so sufficient adhesion can be obtained even in the adhesive portion of the container body that has a slight step.

As shown in Figs. 1 and 2, the container body 20 and the lid 40 are configured such that the diameter D1 at the convex fitting portion 55 of the lid 40 is larger than the diameter D2 at the groove-shaped fitting portion 50 of the container body 20 (D1>D2). The diameter D1 at the convex fitting portion 55 of the lid 40 corresponds to the distance between the apexes (most protruding positions) of the convex fitting portions 55. The diameter D2 at the groove-shaped fitting portion 50 of the container body 20 corresponds to the distance between the upper inner peripheral wall portion 24c of the groove-shaped fitting portion 50 (the boundary portion between the groove-shaped fitting portion 50 and the inner peripheral wall portion 24a).

Since the diameter D1 at the convex fitting portion 55 of the lid 40 is larger than the diameter D2 at the groove-shaped fitting portion 50 of the container body 20, the convex fitting portion 55 can be properly fitted to the groove-shaped fitting portion 50. In addition, when the apex of the convex fitting portion 55 abuts (presses) against the apex (the most recessed position) of the groove-shaped fitting portion 50, good adhesion is obtained between the convex fitting portion 55 and the groove-shaped fitting portion 50, and the fitted state can be more properly maintained. If the diameter D1 at the convex fitting portion 55 of the lid 40 is equal to or smaller than the diameter D2 at the groove-shaped fitting portion 50 of the container body 20, a problem occurs in which the convex fitting portion 55 cannot be fitted to the groove-shaped fitting portion 50. The upper limit of the diameter D1 of the lid 40 at the position of the convex fitting portion 55 is an appropriate distance that allows it to be press-fitted into the container body 20 and to be fitted into the concave fitting portion 50.

As shown in FIG. 4, the container body 20 and the lid 40 have a protruding length L1 of the ridge fitting portion 55 of the lid 40 that is greater than or equal to the depth L2 of the groove-like fitting portion 50 of the container body 20. The protruding length L1 of the ridge fitting portion 55 of the lid 40 corresponds to the distance from the outer periphery 35a of the hanging portion 43 to the apex of the ridge fitting portion 55. The depth L2 of the groove-like fitting portion 50 of the container body 20 corresponds to the distance from the upper inner wall portion 24c of the groove-like fitting portion 50 to the apex of the groove-like fitting portion 50.

By making the protruding length L1 of the convex fitting portion 55 of the lid 40 equal to or greater than the depth L2 of the groove-shaped fitting portion 50 of the container body 20, the convex fitting portion 55 can be more reliably pressed against the groove-shaped fitting portion 50 when the convex fitting portion 55 and the groove-shaped fitting portion 50 are fitted together, and the adhesion between the convex fitting portion 55 and the groove-shaped fitting portion 50 is further improved. If the protruding length L1 of the convex fitting portion 55 of the lid 40 is less than the depth L2 of the groove-shaped fitting portion 50 of the container body 20, there is a risk that sufficient adhesion between the convex fitting portion 55 and the groove-shaped fitting portion 50 cannot be obtained. In particular, if the diameter D1 of the convex fitting portion 55 of the lid 40 at the position of the convex fitting portion 55 is too small, there is a risk that the fitting between the convex fitting portion 55 and the groove-shaped fitting portion 50 of the container body 20 is released and the lid 40 becomes easily detached.

The width and depth of the groove-shaped fitting portion 50 and the width and protruding length of the ridge fitting portion 55 are not particularly limited as long as the width of the groove-shaped fitting portion 55 is equal to or less than the width of the groove-shaped fitting portion 50 and the protruding length of the ridge fitting portion 55 is equal to or greater than the depth of the groove-shaped fitting portion 50, so that the two can be properly fitted together. For example, the width of the groove-shaped fitting portion 50 is about 1.5 to 5 mm, the depth is about 0.2 to 1.0 mm, and the width of the ridge fitting portion 55 is about 1 to 4 mm, and the protruding length is about 0.2 to 1.0 mm. If the width and depth of the groove-shaped fitting portion 50 and the width and protruding length of the ridge fitting portion 55 are not appropriate, the fitting may be easily released or sufficient adhesion may not be obtained.

In the case of the paper container 10, when the hanging portion 43 of the lid 40 is inserted into the upper opening of the container body 20 to close the lid, as shown in FIG. 7, at least the lower side of the inner wall portion 24a between the upper opening 21 of the container body 20 and the groove-shaped fitting portion 50 is located inside the convex fitting portion 55 of the lid 40. When closing the lid, the convex fitting portion 55 of the lid 40 is pressed into the inner wall portion 24a of the container body 20, and is fitted when the convex fitting portion 55 reaches the groove-shaped fitting portion 50 as shown in FIG. 3.

In this way, in the paper container 10 of the present invention, a groove-shaped fitting portion 50 is formed on the inner wall portion 24a of the container body 20, and a protruding fitting portion 55 is formed on the outer periphery 35a of the hanging portion 43 of the lid body 40, and the protruding fitting portion 55 is fitted into the groove-shaped fitting portion 50 when the lid is closed, thereby holding the lid body 40 in an internally fitted state with respect to the container body 20. Therefore, compared to conventional external fitting, it is easier to respond to errors in the formability of the paper container body 20, it is possible to suppress the effects of the forming accuracy when the lid is closed, and the adhesion of the fitting portion between the container body 20 and the lid body 40 is improved. Therefore, it is possible to effectively suppress the unexpected leakage of food and drink contained in the container body 20. In particular, since it is possible to appropriately suppress the leakage of liquid, it is suitable for storing food and drink that contains a lot of liquid, such as soups and noodles.

As described above, the paper container with lid of the present invention suppresses the effects of molding precision of the container body and enhances adhesion between the container body and the lid, so the lid can be properly closed simply by fitting the container body together, and various types of food and drink can be properly stored, including liquid foods and drinks such as soups and noodles. Therefore, it is a promising alternative to conventional paper containers.

Reference Signs List 10 Paper container with lid 20 Container body 21 Top opening 22 Outer rolled edge 23 Container bottom 23s Bottom paperboard 24 Container body 24a Inner wall 24b Outer wall 24c Inner wall above groove-shaped fitting 24s Body paperboard 25 Outer ridge 28 Bottom paperboard fold 29 Body paperboard fold 30 Insulation 31 Insulation paper sleeve 35 Air space 40 Lid 41 Lid surface 42, 42a Lid flange 43 Hanging portion 43a Outer periphery of hanging portion 45, 45a, 45b Steam hole 46 Concave surface 50 Groove-shaped fitting 55 Ridge fitting D1 Diameter at ridge fitting position D2 Diameter at the groove-shaped fitting position L1 Protruding length of the protruding fitting portion L2 Depth of the groove-shaped fitting portion

Claims (5)

A container body made of paper or a material mainly made of paper or plant fiber, having a cylindrical shape or an inverted truncated cone shape with an upper opening, and a groove-like fitting portion 50 formed on an inner peripheral wall portion 24a near the edge of the upper opening and running parallel to the upper opening;
a cover body having a cover surface portion covering the upper opening of the container body, and a hanging portion provided around the outer periphery of the cover surface portion so as to enter the upper opening of the container body and come into contact with or be close to the inner peripheral wall portion, the cover body having a protruding fitting portion formed on the outer periphery of the hanging portion,
a diameter D1 of the lid body at the position of the convex stripe fitting portion is larger than a diameter D2 of the container body at the position of the concave groove-shaped fitting portion (the distance between the upper inner wall portion 24c of the concave groove-shaped fitting portion 50, which is the boundary portion between the concave groove-shaped fitting portion 50 and the inner wall portion 24a), and a protruding length L1 of the convex stripe fitting portion is configured to be greater than or equal to a depth L2 of the concave groove-shaped fitting portion, so that when the lid is closed, the convex stripe fitting portion is pressed against the concave groove-shaped fitting portion to fit therein. The paper container with lid according to claim 1, wherein the lid is made of a synthetic resin sheet. The paper container with lid according to claim 1 or 2, in which a heat insulating portion is formed on the outside of the container body. The paper container with lid according to claim 3, wherein the heat insulating portion is formed by wrapping an insulating paper sleeve around the container. The paper container with lid according to claim 4, wherein the insulating paper sleeve is embossed paper.

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