Lid, container with the same, and combination of lid and container

Abstract

To provide: a lid which, when used as a lid made of a paper-based material, can be prevented from rupturing or from separating from a container when the internal pressure inside a container with the lid attached increases; a container with the same; and a combination of the lid and the container.SOLUTION: When attached to the container, a top surface portion 11 has multiple paper-based base materials and has a layered structure where the multiple paper-based base materials are stacked. Each of the multiple paper-based base materials has multiple fibers. A surface of the paper-based base material directly or indirectly facing an opening of the container is defined as an opposing surface. When the surface opposite the facing surface is designated as an exposed surface, the paper-based base material has structure where the multiple fibers are made to cross to form a gas passageway extending from the facing surface to the exposed surface. The layered structure has a partially bonded section 20 where at least two of the paper-based base materials are partially bonded.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a lid, a container with a lid, and a combination of a lid and a container. [Background technology]

[0002] BACKGROUND ART It is common practice to place food, beverages, etc. (hereinafter also referred to as "contents") in a container with an opening at the top and then attach a lid to provide the container in a closed state.

[0003] From the viewpoint of reducing the environmental impact and the use of petroleum raw materials, it is desirable to use lids made of paper-based materials for lids attached to containers. A known method for attaching a lid to a container is to join the lid to the edge that forms the outer periphery of the opening at the top of the container using a method such as heat pressing (sealing method). To consume the contents from a container with a lid attached (a container with a lid), as shown in Patent Document 1, the lid is peeled off (removed) from the edge of the container, and the lid may also be partially destroyed to form an opening in the container with a lid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-84128 Summary of the Invention [Problem to be solved by the invention]

[0005] When the contents contained in the container with a lid are those that release steam or gas, such as hot beverages or cold carbonated beverages, the release of steam or gas increases the internal pressure of the container with a lid, and the liquid in the released steam or gas increases the internal pressure of the container with a lid. This leaves room for improvement in terms of preventing the lid from bursting or separating from the container at a timing unintended by the user. Preventing the lid from bursting or separating from the container at a timing unintended by the user is also important from the perspective of preventing liquid components that leak out of the container while mixed with the gas from coming into contact with the user's body.

[0006] In view of the above, the object of the present invention is to provide a lid, a container with a lid, and a combination of a lid and a container, which is made of a paper-based material and can prevent the lid from bursting or the container from separating when the internal pressure inside the container with a lid increases while the container is in the lid-equipped state. [Means for solving the problem]

[0007] The present invention is summarized as follows (1) to (11).

[0008] (1) A lid that is configured to be able to be attached to a container having an opening and an edge that forms the opening, and that has a top surface that covers the opening when attached to the container, the top surface having a plurality of paper-based substrates and a layered structure in which a plurality of the paper-based substrates are stacked, each of the plurality of paper-based substrates having a plurality of fibers, and when the surface of the paper-based substrate that directly or indirectly faces the opening of the container is defined as an opposing surface and the surface opposite the opposing surface is defined as an exposed surface, the paper-based substrate has a structure in which a plurality of the fibers are crossed to form a gas passage path that connects from the opposing surface to the exposed surface, and the layered structure has a partial adhesive portion in which at least two of the paper-based substrates are partially adhered. (2) The lid body according to (1) above, wherein the overlapping structure has a gap between the paper-based base materials facing each other. (3) The lid according to (1) or (2) above, wherein when the paper substrate arranged closest to the opening of the container is a first paper substrate and the paper substrate directly facing the first paper substrate is a second paper substrate, the basis weight of the first paper substrate is smaller than the basis weight of the second paper substrate. (4) The lid described in (1) or (2) above, in which the thickness of the first paper substrate is smaller than the thickness of the second paper substrate when the paper substrate arranged closest to the opening of the container is a first paper substrate and the paper substrate directly facing the first paper substrate is a second paper substrate. (5) A lid according to (1) or (2) above, wherein when the paper substrate arranged closest to the opening of the container is a first paper substrate and the paper substrate directly facing the first paper substrate is a second paper substrate, the air permeability of the first paper substrate is smaller than the air permeability of the second paper substrate. (6) A lid according to (1) or (2) above, wherein the paper substrate has a through hole formed therethrough in the thickness direction of the paper substrate, and a cross section of the fiber is exposed on the inner surface of the through hole. (7) The lid according to (1) or (2) above, wherein the partially bonded portion is a portion where at least two of the paper-based base materials are bonded together via an adhesive. (8) A lid according to (1) or (2) above, in which, when the paper substrate arranged closest to the opening of the container is a first paper substrate, a liquid repellent agent is adhered to the first paper substrate. (9) A container with a lid, comprising the lid described in (1) above, and a container body having an opening formed at the top end and an edge forming the outer periphery of the opening, and having a joint that joins the lid to the container. (10) A container with a lid described in (9) above, wherein a resin coating layer is provided on the inner surface of the container body, and the joint is an adhesive joint that bonds the container body and the lid body via the resin coating layer. (11) A combination of a lid and a container, comprising the lid described in (1) above and the container having the opening formed at the top end and an edge forming the outer periphery of the opening. [Effects of the Invention]

[0009] According to the present invention, it is possible to provide a lid made of a paper-based material, a container with a lid, and a combination of a lid and a container that can prevent the lid from bursting or the container from separating when the internal pressure inside the container with a lid increases while the container is in the lid-equipped state. [Brief explanation of the drawings]

[0010] [Figure 1] Fig. 1A is a plan view illustrating an example of a lid according to the first embodiment, Fig. 1B is a bottom view illustrating an example of a lid according to the first embodiment, and Fig. 1C is a cross-sectional view schematically illustrating a state of a vertical cross section taken along line AA in Fig. 1A. [Figure 2] Fig. 2A is a partially enlarged cross-sectional view schematically showing the state of an area XS1 surrounded by a dashed line in Fig. 1C. Fig. 2B is a partially enlarged cross-sectional view schematically showing the state of a portion corresponding to the area XS1 surrounded by a dashed line in Fig. 1C in a second embodiment. Fig. 2C is a partially enlarged cross-sectional view schematically showing the state of a portion corresponding to the area XS1 surrounded by a dashed line in Fig. 1C in a third embodiment. [Figure 3] 3A and 3B are diagrams showing an example of a paper-based substrate, and Fig. 3C is a diagram for explaining the breathability of the paper-based material. [Figure 4] 4A and 4B are cross-sectional views illustrating another example of the lid according to the first embodiment. [Figure 5] Fig. 5A is a plan view illustrating an example of a lid according to Modification 1 of the first embodiment. Fig. 5B is a bottom view illustrating an example of a lid according to Modification 1 of the first embodiment. Fig. 5C is a cross-sectional view schematically illustrating a vertical cross section taken along line BB in Fig. 5A. [Figure 6]Fig. 6A is a plan view illustrating an example of a lid according to Modification 2 of the first embodiment. Fig. 6B is a bottom view illustrating an example of a lid according to Modification 1 of the first embodiment. Fig. 6C is a cross-sectional view schematically illustrating a state of a vertical cross section taken along line CC in Fig. 5A. [Figure 7] Fig. 7A is a plan view illustrating an example of a lid according to Modification 2 of the first embodiment. Fig. 7B is a cross-sectional view schematically illustrating a vertical cross section taken along line DD in Fig. 7A. Fig. 7C is a cross-sectional view illustrating another example of a lid according to Modification 3 of the first embodiment. [Figure 8] Fig. 8A is a plan view for explaining an example of a lid according to Modification 2 of the first embodiment, and Fig. 8B is a cross-sectional view schematically showing the state of a vertical cross section taken along line EE in Fig. 8A. [Figure 9] 9A to 9C are diagrams showing an example of a state in which a liquid repellent agent is attached to fibers of a paper-based base material in a lid according to the fourth modification of the first embodiment. [Figure 10] Fig. 10A is a plan view for explaining an example of a lid according to the second embodiment, Fig. 10B is a bottom view for explaining an example of a lid according to the second embodiment, and Fig. 10C is a cross-sectional view schematically showing the state of a vertical cross section taken along line FF in Fig. 10A. [Figure 11] Fig. 11A is a plan view for explaining an example of a lid according to the third embodiment, Fig. 11B is a bottom view for explaining an example of a lid according to the third embodiment, and Fig. 11C is a cross-sectional view schematically showing the state of a vertical cross section taken along line GG in Fig. 11A. [Figure 12] Fig. 12A is a perspective view illustrating one embodiment of a container with a lid, Fig. 12B is a cross-sectional view schematically illustrating a vertical cross section taken along line HH in Fig. 12A and a partially enlarged cross-sectional view schematically illustrating an enlarged portion of region XRA surrounded by a dashed line. DETAILED DESCRIPTION OF THE INVENTION

[0011] An embodiment of the present invention will be described below with reference to the drawings. The description will be given in the following order: 1. First embodiment, 2. Second embodiment, 3. Third embodiment, and 4. Application example. In this specification and the drawings, components having substantially the same functional configuration will be assigned the same reference numerals, and redundant description will be omitted.

[0012] The following description is of a preferred specific example of the present invention, and the content of the present invention is not limited to the described embodiments. Furthermore, in the following description, directions such as front-back, left-right, and up-down are indicated for the sake of convenience, but the content of the present invention is not limited to these directions. In the examples of FIGS. 1 and 2, the Z-axis direction is the up-down direction (the upper side is the +Z direction, and the lower side is the -Z direction), the X-axis direction is the front-back direction (the front side is the +X direction, and the rear side is the -X direction), and the Y-axis direction is the left-right direction (the right side is the +Y direction, and the left side is the -Y direction), and the description will be based on this. The same applies to FIGS. 3 to 12.

[0013] The relative size and thickness ratios of each layer shown in each drawing, such as Figure 1, are shown for convenience and do not limit the actual size ratios. The same definitions regarding these directions and size ratios apply to each drawing, such as Figures 2 to 12.

[0014] The lid of the present invention will be described using an example of a lid used for a container (cup) for holding a fluid such as a coffee cup or other beverage. However, the lid is not limited to a lid for a beverage container and can also be used for a container for holding food products containing liquid other than beverages. Furthermore, the lid of the present invention may also be used for containers that can hold various liquid items other than food and beverages. Furthermore, while the lid of the present invention will be described below using an example of a lid that is circular in plan view, the shape of the lid is not limited to a circular shape in plan view and can be applied to various shapes other than a circle, such as an ellipse, a polygonal shape such as a rectangle or a triangle, a chamfered rectangle, or a chamfered polygon. However, from the perspective of further enhancing the effects of the present invention, it is preferable that the lid be attached to a container that contains a mixed fluid or a substance containing a mixed fluid.

[0015] In this specification, a mixed fluid refers to a fluid having a gas phase containing gas and a liquid phase containing liquid, and examples thereof include a liquid having bubbles (in this case, the gas phase is the gas within the bubbles and the liquid phase is composed of the liquid surrounding the bubbles) and a fluid having (dispersed) aerosol-like droplets in a gas (in this case, the gas phase is the gas surrounding the aerosol-like droplets and the liquid phase is composed of the liquid that forms the droplets).

[0016] As described above, the contents to be contained in the container with a lid may be a fluid (liquid fluid) such as a liquid substance that emits steam or gas, such as a hot beverage or a cold carbonated beverage, and in this specification, such liquid fluids that emit steam or gas, such as a hot beverage or a cold carbonated beverage, may be referred to as a gas-releasing fluid.

[0017] [1. First embodiment] [1-1 Configuration] The lid 10 according to the first embodiment is configured so that it can be attached (adhered) to an edge 103 of an opening 102 of a container 101, as will be described later using Figures 12A, 12B, etc. In other words, the lid 10 is formed so that a contactable area that comes into contact with the edge 103 of the container 101 having the opening 102 can be formed on the opposing surface of the lid 10. A container 101 in which the lid 10 is attached to the edge 103 of the opening 102 is called a lidded container 150. The lid 10 is configured so that it can cover the opening 102 of the container 101 that constitutes the lidded container 150.

[0018] In this specification, the opposing surface 73 of the lid 10 refers to the surface opposite to the exposed surface 72, and the exposed surface 72 of the lid 10 refers to the surface exposed to the outside when the lid-equipped container 150 is in the lid-equipped container state. Therefore, the opposing surface 73 refers to the surface of the top surface 11 of the lid 10 that faces the container 101 when the lid-equipped container 150 is in the lid-equipped container state. In describing each part of the lid 10, for example, with respect to a surface such as the top surface 11, a surface facing the same direction as the exposed surface 72 of the lid 10 may be simply referred to as the exposed surface, and a surface facing the same direction as the opposing surface 73 of the lid 10 may be simply referred to as the opposing surface. Therefore, of the surfaces of the paper-based substrate described below, the surface that directly or indirectly faces the opening of the container may be referred to as the opposing surface, and the surface opposite the opposing surface may be referred to as the exposed surface. This also applies to the second and third embodiments.

[0019] The lid body 10 has a top surface 11. In the example shown in Figures 1A to 1D, the lid body 10 has the top surface 11 and a portion (outer edge portion 12) outside the top surface 11. The outer edge portion 12 is configured as a part of an outer region corresponding portion 95C (a portion of the outer region corresponding portion 95C excluding the joint region corresponding portion 95A). In Figure 1A etc., the symbol CT indicates the center of the lid region corresponding portion 95B.

[0020] (Top part) 1A to 1D, top surface 11 is configured so as to be attachable to a container having an opening 102 and an edge 103 that forms opening 102, and when lid 10 is attached (bonded) to container 101, it covers opening 102 of container 101. The shape of top surface 11 may be determined according to the shape of container 101, and examples include a circular shape, an elliptical shape, a triangular shape, a rectangular shape, a polygonal shape, and a chamfered shape.

[0021] (Touchable area) The lid 10 has a contactable area on the opposing surface 73 side of the top surface 11. The contactable area of ​​the lid 10 is defined as a bonding area R. In the present invention, the bonding area R is an area (adhesion area) where the lid 10 and the edge 103 of the container are bonded together. The bonding area R is defined as an area corresponding to the shape of the edge 103 of the container 101, and when the edge 103 is formed in a roughly circular shape as in the example shown in FIG. 1A, the bonding area R is circular.

[0022] The lid body 10 has a joint area corresponding portion 95A. As shown in Figures 1A, 1B, 1C, etc., the lid body 10 also has a lid area corresponding portion 95B and an outer area corresponding portion 95C. The lid area corresponding portion 95B is configured as a portion that covers the opening 102. The outer area corresponding portion 95C is configured as a portion outer than the lid area corresponding portion 95B.

[0023] When viewed in a plane, the top surface portion 11 is the portion inward from the outer peripheral edge of the joint area corresponding portion 95A of the lid body 10, and in the example of Figure 1A, etc., it can be identified as the portion combining the joint area corresponding portion 95A and the lid area corresponding portion 95B.

[0024] (Part corresponding to the joining area) The bonding area corresponding portion 95A is a portion of the lid 10 corresponding to a region that is bonded to the container 101 along the edge 103 of the container 101. That is, the bonding area corresponding portion 95A is a portion of the lid 10 that corresponds to the bonding area R (a region facing the edge 103 of the container 101 and bonded to the container 101) that will be the adhesive region. In the lid-equipped container 150, the bonding area corresponding portion 95A is a portion of the lid 10 that forms the contact portion 151 between the lid 10 and the container 101. Specifically, in a plan view of the lid 10 (when the line of sight is in the Z-axis direction (vertical direction) in the examples of FIGS. 1A to 1C ), the portion that forms the bonding area R is defined as the bonding area corresponding portion 95A. The bonding area corresponding portion 95A is usually formed in a ring shape as shown in FIG. 1A . In particular, as shown in FIG. 12A , when the edge 103 of the container 101 is formed in a generally annular shape, the bonding region R is also annular, and the corresponding bonding region 95A is also generally annular in a plan view of the lid 10. The outer edge of the corresponding bonding region 95A is determined according to the position of the outer edge of the bonding region R. The outer edge of the corresponding bonding region 95A may be located on the outer periphery of the lid 10 (in which case the corresponding bonding region 95A and the corresponding outer region 95C coincide with each other), or may be located inside the outer periphery of the lid 10 as shown in the example of FIG. 1A . When the bonding region R between the lid 10 and the container 101 is not formed continuously, the portion sandwiched between adjacent bonding regions R and facing the edge 103 is also included in the corresponding bonding region 95A, which will be described later.

[0025] (Corresponding to the lid area) The lid region corresponding portion 95B is a portion that covers the opening 102 (a portion located directly above the opening 102) when the lid-equipped container 150 is in the state shown in FIG. 1A, the lid region corresponding portion 95B is a portion of the lid 10 that is inward from the joining region corresponding portion 95A. The lid region corresponding portion 95B is a portion that covers the opening 102 in the lid-equipped container 150. Note that the portion that covers the opening 102 refers to a portion that covers at least a portion of the opening 102, and includes a case where the portion has a portion that can be partially opened, such as an insertion port 16, as will be described later.

[0026] (Outer area corresponding part) 13A, the portion outside the lid region corresponding portion 95B of the lid body 10 is the outer region corresponding portion 95C, which is the same portion as the bonding region corresponding portion 95A or a portion including the bonding region R. In the example of FIG. 1, the outer region corresponding portion 95C is composed of the outer edge portion 12 and the bonding region corresponding portion 95A.

[0027] (Paper base material) The top surface 11 has a plurality of paper-based substrates 14. The paper-based substrates 14 have a plurality of fibers 15 and are defined as sheet-like members. The paper-based substrates 14 are defined as sheet-like members made of a paper-based material. That is, it is preferable that the paper-based substrates 14 are made of a paper-based material. In the example of FIG. 1A, it is preferable that the entire top surface 11 is made of the paper-based substrates 14 (that is, the entire lid 10 is formed of the paper-based substrates 14).

[0028] (paper-based materials) Examples of paper-based materials include so-called paper, which is obtained by weaving a slurry of a fiber-containing raw material onto a screen, drying or pressing and drying it, and making it into a sheet; so-called air-laid sheets, which are obtained by stacking spread fiber raw materials such as ground pulp obtained by pulverizing a raw material sheet made of pulp-based fibers or the like in a grinder, using an air flow to fix the fibers in the stack to each other with a binder; and so-called papers, which are produced by agglutinating plant fibers and other fibers.

[0029] The fibers 15 forming the paper substrate 14 (i.e., the fibers forming the paper material) are preferably so-called paper fibers (pulp fibers). Examples of pulp fibers include wood pulp fibers and non-wood pulp fibers. For both wood pulp and non-wood pulp, virgin pulp is preferred from the viewpoint of maintaining a relatively long fiber length. Furthermore, among wood pulps, unbleached kraft pulp (UKP), bleached kraft pulp (BKP), or a combination thereof is preferred for the pulp fibers, as these wood pulps produce base paper with excellent wet strength. Unbleached pulp refers to wood pulp that has not been bleached. Bleached pulp refers to wood pulp that has undergone a bleaching process. Examples of bleaching methods for bleached pulp include bleaching methods that use alkali, chlorine, sodium hypochlorite, etc., bleaching methods that use chlorine dioxide, etc. (ECF (Elementary Chlorine Free) bleaching method), bleaching methods that use oxygen, hydrogen peroxide, ozone, etc. (TCF (Total Chlorine Free) bleaching method), etc. Examples of non-wood pulp include linter pulp, kenaf pulp, bagasse pulp, pambu pulp, and hemp pulp.

[0030] Furthermore, paper-based materials may be made solely of pulp or may contain non-pulp natural fibers, synthetic fibers, recycled fibers, or other fibers, but preferably contain pulp as the main component (50% by mass or more), more preferably 70% by mass or more, and even more preferably 80% by mass or more, with 100% by mass of pulp being particularly preferred. Paper-based materials can also be used as composite materials with wood-based materials such as wood foil, or even aluminum foil, but when used as composite materials, the composite material as a whole preferably contains 50% by mass or more of pulp, and particularly preferably 80% by mass or more of pulp. The higher the pulp content, the more easily the paper-based material is biodegraded, which is preferable.

[0031] Paper-based materials are sheet materials made from fibers, and are preferably used in which the formation of a layer (coat layer) of a coating agent or the like over the entire surface of the sheet material is avoided. By avoiding the formation of a coating layer that covers the entire surface of the sheet material, a lid that is more suitable for recyclability can be formed. However, if a coating agent that can be dissolved in a solvent or the like is used, the formation of a coating layer on the paper-based material is not prohibited.

[0032] Although the paper-based material is preferably made of a fiber material such as pulp, this does not prohibit the inclusion of various resins in addition to the fiber material, as long as they are not the main component. However, when the paper-based material contains various resins, it is preferable to select biodegradable resins that cause less environmental pollution. Biodegradable resins include, for example, microbially produced biodegradable resins such as polyhydroxyalkanoates (PHAs) and PHA-based copolymers; natural product-based biodegradable resins such as cellulose derivatives such as cellulose acetate and starch-based resins made primarily from starch such as corn starch; lactic acid-based resins such as polylactic acid (PLA), polylactic acid / polycaprolactone copolymers, and polylactic acid / polyether copolymers; succinate-based resins such as polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), and polyethylene terephthalate succinate (PETS); chemically synthesized biodegradable resins such as polycaprolactone and polyvinyl alcohol (PVA); and other biodegradable resins such as polyglycolic acid (PGA), polybutylene adipate / terephthalate, and biodegradable polyolefins (product name: Biorecover, product name: Cra Drop, etc.).

[0033] In addition to fibrous materials such as pulp, additives may be added to the paper-based material as needed. Examples of additives include various compounds such as paper strength agents, fillers, and sizing agents. Specific examples of additives that may be added to the paper-based material include starch-based compounds and alkyl ketene dimers (AKDs). The starch-based compounds used are preferably those that can function as paper strength agents. The alkyl ketene dimers are preferably those that can function as sizing agents. From the perspective of reducing environmental impact, when a resin is used as an additive, it is preferably a non-synthetic resin, and for example, a biodegradable resin is preferably used.

[0034] (Intertwining structure) The paper-based substrate 14 has a structure in which a plurality of fibers 15 are crossed to form a gas passage path connecting the opposing surface 73 to the exposed surface 72 (the structure in which a plurality of fibers 15 are crossed is referred to as an intertwined structure). That is, the paper-based substrate 14 has an intertwined structure. The paper-based substrate 14 is defined as having breathability without requiring a separate process for forming perforations or slits for ventilation (a perforation forming process) on a sheet formed from a paper-based material. Such a paper-based substrate 14 can be realized by employing a sheet formed from a paper-based material with reduced fiber basis weight and bulky (increased thickness). By reducing the fiber basis weight and making the paper-based substrate 14 bulky, the fiber density is reduced, which makes it easier for gaps to form between the intertwined fibers overall. In the paper-based material, the gaps between the fibers 15 tend to be connected in the thickness direction of the paper-based substrate 14, and as shown in Figure 3C, a state in which a passage is formed through which gas can pass in the direction of the arrows FG from one side to the other side of the paper-based substrate 14 is easily formed. By using such a paper-based substrate 14, it is possible to achieve the above-mentioned "state in which a gas passage path connecting from the opposing surface to the exposed surface is formed in the paper-based substrate 14."

[0035] In the paper-based substrate 14, the gas passage paths may be formed over the entire area of ​​the paper-based substrate 14, or may be formed only in specific areas. Furthermore, in the paper-based substrate 14, the areas where the gas passage paths are formed may be formed in a predetermined layout.

[0036] (Breathability) The paper-based substrate 14 has air permeability because it has gas passageways. The air permeability of the paper-based substrate 14 can be specifically determined by, for example, air permeability. Air permeability is calculated by the average flow rate ([mL / (m) 2 ·Pa·s), i.e., [μm / (Pa·s)]. The air permeability can be measured, for example, by a method conforming to JIS P 8117. The magnitude of the air permeability of the paper-based substrate 14 can be determined based on a comparison of the magnitude of the air permeability values.

[0037] (Superimposed structure) The top surface 11 has a superimposed structure 17 in which multiple paper-based substrates 14 are stacked. In the example of Figures 1A to 1C, the entire top surface 11 forms the superimposed structure 17. However, this does not limit the superimposed structure 17 to only the lid region corresponding portion 95B. It is sufficient that at least the lid region corresponding portion 95B forms the superimposed structure 17. However, from the viewpoint of improving the uniformity of the overall thickness of the top surface 11 of the lid body 10 and thereby improving the uniformity of the strength of the lid body 10, it is preferable that the entire top surface 11 forms the superimposed structure 17.

[0038] In the example of FIG. 1C, the overlapping structure 17 is defined as a structure in which two paper-based substrates 14 are stacked. The paper-based substrate 14 located closest to the opening 102 of the container 101 is referred to as the first paper-based substrate 14A, and the paper-based substrate 14 directly facing the first paper-based substrate 14A is referred to as the second paper-based substrate 14B. When the first paper-based substrate 14A and the second paper-based substrate 14B are not particularly distinguished, they are collectively referred to as the paper-based substrate 14. Note that the example of FIG. 1C illustrates an example of the present invention, and the number of paper-based substrates 14 in the overlapping structure 17 is not limited to two, as long as the overlapping structure 17 has a structure in which multiple paper-based substrates 14 are stacked. As shown in FIG. 4A, the overlapping structure 17 may have three or more paper-based substrates 14 stacked on top of each other. However, from the perspective of reducing manufacturing costs and easily ensuring the size of the gaps between the paper-based substrates 14, it is preferable that the overlapping structure 17 has a structure in which two paper-based substrates 14 are stacked on top of each other.

[0039] (Basic weight) The basis weight of each of the paper-based substrates 14 constituting the overlapping structure 17 is not particularly limited, but the basis weight (g / m 2 ) is the basis weight (g / m 2 ) is preferably smaller than the first paper-based substrate 14A. When the basis weight of the first paper-based substrate 14A is smaller than the basis weight of the second paper-based substrate 14B, the flexibility of the first paper-based substrate 14A is likely to be greater than the flexibility of the second paper-based substrate 14B. In other words, the rigidity of the second paper-based substrate 14B is likely to be greater than the rigidity of the first paper-based substrate 14A. Therefore, when the contents of the lidded container 150 are gas-releasing fluids such as hot liquids or carbonated drinks, even if gas such as steam released from the contents accumulates in the gap 18 between the second paper-based substrate 14B and the first paper-based substrate 14A while the lidded container 150 is in a state where the lidded container 150 is in a state where the lidded container 150 is in a state where the second paper-based substrate 14B is in a gas-releasing fluid state, deformation of the second paper-based substrate 14B is more likely to be suppressed than that of the first paper-based substrate 14A, and the shape stability of the appearance of the lidded container 150 can be improved.

[0040] (Thickness) The thicknesses of the paper-based substrates 14 constituting the superposed structure 17 may be the same, or the thicknesses of at least some of the paper-based substrates 14 may be different, or the thicknesses of the paper-based substrates 14 may be different from one another. For example, when the superposed structure 17 is formed by stacking three paper-based substrates 14, the thicknesses of the three paper-based substrates 14 may be the same, or the thicknesses of two paper-based substrates 14 may be the same but different from the thickness of the other paper-based substrate 14, or the thicknesses of the three paper-based substrates 14 may be different from one another.

[0041] 4B, in the overlap structure 17, the thickness of the first paper-based substrate 14A may be smaller than the thickness of the second paper-based substrate 14B, i.e., the thickness of the second paper-based substrate 14B may be greater than the thickness of the first paper-based substrate 14A. In this case, similar to the basis weight described above, the shape stability of the appearance of the lidded container 150 can be improved.

[0042] (density) The densities of the paper-based substrates 14 constituting the superposed structure 17 may be the same, or the densities of at least some of the paper-based substrates 14 may be different, or the densities of the paper-based substrates 14 may be different from one another. For example, when the superposed structure 17 is formed by stacking three paper-based substrates 14, the densities of the three paper-based substrates 14 may be the same, or the densities of two paper-based substrates 14 may be the same and different from the density of another paper-based substrate 14, or the densities of the three paper-based substrates 14 may be different from one another.

[0043] Regarding the density of the paper-based substrate 14, when comparing the density of a paper-based substrate placed relatively close to the container 101 with the density of a paper-based substrate placed relatively far from the container 101, it is preferable that the density of the paper-based substrate placed relatively close to the container 101 is higher, from the viewpoint of balancing between temporarily trapping gas released from the gas-releasing fluid through the lid 10 and maintaining the function of the lid 10 covering the container 101.

[0044] 1, the density of the fibers constituting the first paper-based substrate 14A is preferably greater than the density of the fibers constituting the second paper-based substrate 14B. In such a case, the size of the gas passage path of the second paper-based substrate 14B (the size of the spaces 19 (gaps between the fibers 15) between the multiple fibers 15 constituting the second paper-based substrate 14B) tends to be greater than the size of the gas passage path of the first paper-based substrate 14A (the size of the spaces 19 (gaps between the fibers 15) between the multiple fibers 15 constituting the second paper-based substrate 14B), making it easier to make the breathability of the second paper-based substrate 14B greater than that of the first paper-based substrate 14A. By making the breathability of the second paper-based substrate 14B greater than that of the first paper-based substrate 14A, the gas released from the gas-releasing fluid contained in the container 101 of the lidded container 150 is more likely to be temporarily trapped in the gaps between the multiple paper-based substrates 14 that make up the overlapping structure 17 (in the example of Figures 1C and 2, in the gaps 18 between the second paper-based substrate 14B and the first paper-based substrate 14A). In other words, the time that the gas is trapped in the gaps 18 formed between the multiple paper-based substrates 14 can be controlled. The gas released from the gas-releasing fluid passes through the first paper-based substrate 14A and enters the gaps 18. At this time, the gas is less likely to pass through the paper-based material through the first paper-based substrate 14A than through the second paper-based substrate 14B. However, because the second paper-based substrate 14B covers the opening 102, the gas sent to the gaps 18 of the paper-based substrates 14 that make up the overlapping structure 17 is unlikely to immediately diffuse to the outside of the lid 10, and the free diffusion of the gas is prevented by the second paper-based substrate 14B. In other words, the gas is temporarily trapped in the gaps 18 of the paper-based substrates 14 that make up the overlapping structure 17. Then, depending on the breathability of the second paper-based substrate 14B, the gas gradually flows out of the gaps 18. Therefore, as described above, the time for which the gas is trapped in the gaps 18 can be controlled.

[0045] In this way, because the density of the fibers 15 constituting the first paper-based substrate 14A is greater than the density of the fibers 15 constituting the second paper-based substrate 14B, gas is temporarily trapped in the gaps 18 of the paper-based substrates 14 constituting the overlapping structure 17, and the gas is released to the outside of the lidded container 150. This prevents damage to the lidded container 150 (damage due to an excessive increase in internal pressure), and allows gas released from the gas-releasing fluid contained in the container 101 of the lidded container 150 to be appropriately retained inside the lidded container 150. Furthermore, because gas is trapped in the gaps 18 of the paper-based substrates 14 constituting the overlapping structure 17, the gas filling the gaps 18 can respond to the temperature of the contents of the lidded container 150 while improving the thermal insulation of the lid 10 itself. For example, if the contents are a carbonated drink that is colder than room temperature, the temperature of the gas released from the cold carbonated drink is also low, and the temperature of the gas trapped in the gaps 18 of the paper-based substrate 14 that constitutes the overlapping structure 17 is also low, making it possible to improve the heat insulation property while keeping the temperature of the lid 10 itself lower than room temperature. Also, if the contents are hot coffee or the like, the temperature of the steam generated from the coffee or the like is high, and the temperature of the steam trapped in the gaps 18 of the paper-based substrate 14 that constitutes the overlapping structure 17 is high, making it possible to improve the heat insulation property while keeping the temperature of the lid 10 higher. Note that in the examples of Figures 1C and 2, the overlapping structure 17 4A, even when there are three or more paper-based substrates 14 that constitute the superposed structure 17, it is preferable that the density of the fibers 15 that constitute the paper-based substrate 14 that is closer to the container 101 (the paper-based substrate 14 that is relatively closer to the opposing surface 73) is greater than the density of the fibers 15 that constitute the paper-based substrate 14 that is farther from the container 101 (the paper-based substrate 14 that is relatively closer to the exposed surface 72).

[0046] (Partially bonded part) The overlapping structure 17 has a partial adhesive portion 20 formed by partially bonding at least two paper-based substrates 14. The partial adhesive portion 20 is not particularly limited as long as it is configured to partially bond two directly opposing paper-based substrates 14. However, it is preferably formed so as to prevent leakage of gas or mixed fluid from the gap 18 between the two directly opposing paper-based substrates 14 along the surface direction of the lid 10 to the outside of the overlapping structure 17. In the example of FIGS. 1A, 1B, and 1C, the partial adhesive portion is formed in a ring shape at a portion that combines the outer region corresponding portion 95C, including the portion corresponding to the bonding region corresponding portion 95A, and a predetermined portion near the outer periphery of the lid region corresponding portion 95B. That is, the partial adhesive portion 20 is formed from the outer edge portion 12 of the lid 10 toward the inside, extending to the inside of the lid region corresponding portion 95B. Furthermore, in this example, leakage of gas or mixed fluid that has entered gap 18 surrounded by partial adhesive portion 20 along the surface direction of lid 10 to the outside of overlapping structure 17 is restricted. In FIG. 1B, the region where partial adhesive portion 20 is formed is shown as a hatched region. This also applies to FIGS. 5B, 6B, 10B, and 11B.

[0047] The partially bonded portion 20 is not particularly limited as long as it is configured to partially bond the paper substrates 14, but is preferably a portion where at least two paper substrates 14 are bonded via an adhesive 21. Examples of the adhesive 21 include an acrylic adhesive. The partially bonded portion 20 may also be formed by previously disposing a thermoplastic resin such as a polyethylene resin on the paper substrates 14, stacking the paper substrates 14 so that the thermoplastic resin is sandwiched between them, and then heating and pressurizing the paper substrates 14 to bond them via the thermoplastic resin. In this case, the thermoplastic resin functions as the adhesive 21. Examples of methods for previously disposing a thermoplastic resin such as a polyethylene resin on the paper substrate 14 include a method of applying a thermoplastic resin to the paper substrate 14.

[0048] [1-2 Actions and Effects] When the lid and container 101 are bonded by a method such as heat pressing to join the lid to edge 103 that forms the outer periphery of opening 102 at the top of container 101 (i.e., a sealing method (sometimes called a heat sealing method)), and when the content in container 101 is a gas-releasing fluid, the internal pressure in container 101 is likely to increase, and it is therefore necessary to prevent the lid from bursting or the lid from separating from container 101 at a timing not intended by the user. Preventing the lid from bursting or the lid from separating from the container at a timing not intended by the user is also important from the perspective of preventing the possibility of liquid components that leak out of container 101 mixed with the gas coming into contact with the user's body.

[0049] In the lid 10 according to the first embodiment, the top surface 11 of the lid 10 has a stacked structure 17 formed of multiple paper-based substrates 14, each of which has a gas ventilation path. As shown in FIG. 3C , gas contained in the mixed fluid flowing toward the opposing surface 73 passes through the gas passage path formed by the spaces 19 between the multiple fibers 15 in the direction of arrow FL from the opposing surface 73 to the exposed surface 72, while at least a portion of the liquid is impeded by the entangled structure of the fibers 15 and drops off in the direction of arrow FG. Thus, with the lid 10, even if the internal pressure of the container 101 increases, the gas can be appropriately released from the container 101 to the outside. Therefore, a lid 10 made of a paper-based material can be obtained that can prevent the lid 10 from bursting or the container 101 from separating from the lid 10 when the internal pressure of the lid-equipped container 150 increases while the lid-equipped container 150 is in the lid-equipped container state.

[0050] Because the paper-based substrates 14 constituting the lid 10 form gaps 18 where multiple paper-based substrates 14 are stacked, gas released from the gas-releasing fluid contained in the container 101 of the lid-equipped container 150 can be more easily retained inside the lid-equipped container 150 (it can be more easily trapped in the gaps 18), making it difficult for gas to be released more than necessary from the lid-equipped container 150. This can also improve the thermal insulation of the lid 10 itself. Furthermore, because the density of the fibers 15 constituting the paper-based substrate 14 farther from the container 101 is greater than the density of the fibers 15 constituting the paper-based substrate 14 closer to the container 101, trapping of gas in the gaps 18 of the paper-based substrates 14 constituting the stacked structure 17 can be temporary.

[0051] [1-3 Variations] (Variation 1) As shown in FIGS. 5A, 5B, and 5C, the cover 10 according to the first embodiment may have a structure formed in the paper-based substrate 14 that can serve as an insertion port 16. This configuration is referred to as Modification 1 of the first embodiment. In Modification 1 of the first embodiment, the structure that can serve as the insertion port 16 may be a half-cut structure in which the paper-based substrate 14 is cut to a predetermined depth, or a through-hole 22. In Modification 1 of the first embodiment shown in the example of FIG. 5, the through-hole 22 is formed in a portion of the paper-based substrate 14 that constitutes the overlapping structure 17. Furthermore, the through-hole 22 is formed in the second paper-based substrate 14B, and the formation of the through-hole 22 is omitted in the first paper-based substrate 14A. However, this does not limit the formation of the through-hole 22 in all of the paper-based substrates 14 that constitute the overlapping structure 17. However, from the viewpoint of enhancing the effect of trapping gas in the gaps 18 between the multiple paper-based substrates 14 in the overlapping structure 17, it is preferable that the through-hole 22 be formed only in a portion of the paper-based substrate 14 that constitutes the overlapping structure 17. 5A, 5B, and 5C, it is preferable to omit the formation of the through-holes 22 in part of the paper-based substrate 14. When the through-holes 22 are formed in the second paper-based substrate 14B and the formation of the through-holes 22 is omitted in the first paper-based substrate 14A, the position where a straw or the like is to be inserted can be identified from the outside.

[0052] Penetration portion 22 forms a structural portion that functions as insertion port 16 by inserting a straw or the like from the outside into lidded container 150 in the state where lid 10 is adhered to container 101. Therefore, the size of penetration portion 22 is formed to be large enough to allow a straw or the like to be inserted.

[0053] The through-holes 22 are portions that penetrate the paper-based substrate 14 in the thickness direction of the paper-based substrate 14, i.e., have a structure (a structure that penetrates) that is cut in the vertical direction (thickness direction of the top surface 11) from one side to the other side of the lid 10 (from the exposed surface 72 to the opposing surface 73), and are so-called cut structure forming portions. The cut structure forming portion is a portion that is formed in a slit shape. The shape of the through-holes 22 is not particularly limited, and in the example of FIG. 1, they are formed in a cross shape, but this is just an example and does not limit the shape of the through-holes 22. The shape of the through-holes 22 may be a C-shape, a U-shape, or any other shape.

[0054] The shape of the through-hole 22 is not limited to the slit-like shape described above. The through-hole 22 may be formed in a ring shape. In this case, the through-hole 22 may be a hole portion formed by expanding the paper-based substrate 14 (a member forming the top surface 11) or a portion formed by punching the paper-based substrate 14.

[0055] As described above, the through-holes 22 are cut structure forming portions, and therefore, on the inner circumferential surface of the through-holes 22, a cut surface where the fibers 15 constituting the paper-based base material 14 are cut is exposed.

[0056] (Variation 2) As shown in FIGS. 6A, 6B, and 6C, the lid 10 according to the first embodiment may have a grip portion 23 formed as an outward extension of a portion of the outer peripheral edge of the outer edge portion 12. This configuration is referred to as Modification 2 of the first embodiment. When a user attempts to remove or consume contents contained inside the container 101, it may be necessary to forcibly separate the lid and the container. According to Modification 2 of the first embodiment, the user can separate the container and the lid by lifting the lid by holding the grip portion 23 as needed. When the overlapping structure 17 is also formed on the grip portion 23, the partial adhesive portion 20 may also be formed on the grip portion 23. However, this does not prohibit the partial adhesive portion 20 from being formed on the grip portion 23. In the example of FIG. 6, the overlapping structure 17 is also formed on the grip portion 23, but this is merely an example. That is, a part of the paper-based substrate 14 may form a portion corresponding to the gripping portion 23, and the formation of the portion corresponding to the gripping portion 23 may be omitted for the other part of the paper-based substrate 14.

[0057] (Variation 3) In the lid 10 according to the first embodiment, the sizes and shapes of the multiple paper-based substrates 14 forming the overlapping structure 17 are not limited to being the same, and may be different. This form is referred to as Modification 3 of the first embodiment. For example, as shown in the example of FIGS. 7A and 7B, when the paper-based substrates 14 forming the overlapping structure 17 are a first paper-based substrate 14A and a second paper-based substrate 14B, the second paper-based substrate 14B may be larger in size than the first paper-based substrate 14A. Furthermore, as shown in FIG. 7C, the second paper-based substrate 14B may be smaller in size than the first paper-based substrate 14A.

[0058] In the example shown in Figures 8A to 8B, when the paper-based substrates 14 constituting the overlapping structure 17 are a first paper-based substrate 14A and a second paper-based substrate 14B, the shapes of the first paper-based substrate 14A and the second paper-based substrate 14B may be different from each other, with the first paper-based substrate 14A being rectangular and the second paper-based substrate 14B being non-rectangular (approximately circular in the example of Figure 8).

[0059] (Variation 4) In the lid 10 according to the first embodiment, a liquid repellent agent may be applied to the paper-based substrate 14 that forms the overlapping structure 17. This form is referred to as Modification 4 of the first embodiment. In Modification 4 of the first embodiment, when the paper-based substrates 14 that form the overlapping structure 17 are a first paper-based substrate 14A and a second paper-based substrate 14B, a liquid repellent agent 44 is disposed at least on the surface of the first paper-based substrate 14A that faces the opposing surface 73.

[0060] (liquid repellent) The structure in which the liquid repellent agent 44 is disposed on the paper-based substrate 14 refers to a structure in which the liquid repellent agent 44 is in contact with the fibers 15 that form the paper-based substrate 14, as shown in Figure 9A. At least a portion of the liquid repellent agent 44 is adhered to at least a portion of the fibers 15.

[0061] The liquid repellent agent 44 is not limited to being disposed on the surface of the paper substrate 14 or on the fibers 15 located near the surface. It may also be disposed inside the paper substrate 14 (at a position inside the surface along the thickness direction of the paper substrate 14). In this case, even if some of the liquid contained in the mixed fluid penetrates slightly inside the paper substrate, the passage of the liquid can be restricted. As shown in FIG. 3C, gas contained in the mixed fluid heading toward the facing surface 73 passes through the gas passage path formed by the spaces 19 formed between the multiple fibers 15 in the direction of arrow FL from the facing surface 73 to the exposed surface 72. However, at least some of the liquid is blocked by the fibers 15 to which the liquid repellent agent 44 is attached, and is likely to fall off in the direction of arrow FG.

[0062] The liquid repellent agent 44 may be attached to the fibers 15 to such an extent that it can maintain close contact with the fibers 15. In the example of Fig. 9A, the liquid repellent agent 44 is attached in granular form to the surface of the fibers 15, but as shown in Figs. 9B and 9C, the liquid repellent agent 44 may be attached so as to spread in the planar direction of the surface of the fibers 15, or so as to form a layer of the liquid repellent agent 44 that covers the surface of the fibers 15. Furthermore, the liquid repellent agent 44 may penetrate not only the surface of the fibers 15 but also the interior of the fibers 15 (not shown).

[0063] (Type of liquid repellent) The liquid repellent agent 44 is preferably determined according to the type of liquid contained in the container 101 in the state of the lidded container 150. When the liquid contained contains water, a water repellent agent is preferably used as the liquid repellent agent 44. The water repellent agent is not particularly limited, but may be a fluorine-based water repellent agent, a silicone-based water repellent agent, wax, or the like.

[0064] (Method of applying water repellent as a liquid repellent) The method of applying the liquid repellent agent 44 can be, for example, a method of applying a water-repellent treatment to the paper substrate 14. The method of water-repellent treatment is not particularly limited, and can be, for example, a method of immersing the paper substrate 14 in a treatment liquid, pulling out the immersed paper substrate, and then drying it. Another method of water-repellent treatment can be a method of applying a treatment liquid to the surface of the paper substrate. Specific examples of application methods include printing methods. Examples of printing methods include coating methods such as roll coating and spray coating, gravure printing, and screen printing. When using a method of applying water-repellent treatment, the liquid repellent agent 44 is a water repellent agent.

[0065] (Variation 4) In the lid 10 according to the first embodiment, a resin may be attached to at least one surface of the paper substrates 14 forming the overlapping structure 17, except for the paper substrate 14 closest to the opposing surface 73 (Variation 4). In the lid 10 according to Variation 4 of the first embodiment, the resin attached to the surface of the paper substrate 14 may form a layer, or the resin may be arranged so that the resin-attached areas are dispersed on the surface of the paper substrate 14. When the resin attached to the surface of the paper substrate 14 forms a layer, the layer may be formed by coating the resin, or a film material made of resin may be attached to a sheet material made of fibers that constitutes the paper substrate 14. For example, when the overlapping structure 17 is a structure in which a first paper substrate 14A and a second paper substrate 14B are laminated as shown in FIG. 1, the second paper substrate 14B may have a resin attached thereto. In this case, the resin may be attached to either the surface of the second paper-based substrate 14B on the exposed surface 72 side or the surface on the opposing surface 73 side, but it is preferable that the resin be attached to the opposing surface 73 side, as this also serves as an adhesive for bonding the first paper-based substrate 14A and the second paper-based substrate 14B. Examples of resins include polyethylene-based resins.

[0066] [2. Second Embodiment] [2-1 Configuration] As shown in Figures 10A, 10B, and 10C, the lid 10 according to the second embodiment has an overlapping structure 17, and a plurality of small penetration holes 30 are formed in the paper-based substrate 14 that is arranged closest to the exposed surface 72 among the paper-based substrates 14 that form the overlapping structure 17. The lid 10 according to the second embodiment has the same configuration as the first embodiment except for the configuration in which the small penetration holes 30 are formed. Furthermore, variations 1 to 4 of the first embodiment may also be applied to the second embodiment.

[0067] 10A, 10B, and 10C, the overlapping structure 17 has a structure in which a first paper-based substrate 14A and a second paper-based substrate 14B are overlapped. A small through hole 30 is formed in the second paper-based substrate 14B, which is disposed relatively closer to the exposed surface 72 in the top surface 11 of the lid 10. As shown in FIG. 2B, the overlapping structure 17 has a gap 18 formed between the first paper-based substrate 14A and the second paper-based substrate 14B.

[0068] (Small penetration) The small penetration portions 30 are smaller than the penetration portions described in Modification 1 of the first embodiment. The small penetration portions 30 are formed in a portion of the top surface 11 corresponding to the lid region corresponding portion 95B. From the viewpoint of preventing leakage of the contents of the container 101 from the lid-equipped container 150, it is preferable that the small penetration portions 30 be avoided from being formed in a position outside the overlapping structure 17. The shape of the small penetration portions 30 may be hole-like or slit-like, and if hole-like, may be round or elongated. In the example of FIG. 10A , the small penetration portions 30 are formed in slit shapes, and many small penetration portions 30 are formed in the lid region corresponding portion 95B, so that the area where the group of small penetration portions 30 is formed is donut-shaped. However, this is just an example, and the shape of the area where the group of small penetration portions 30 is formed is not particularly limited.

[0069] In the example of the cover 10 according to the second embodiment shown in Fig. 10A, a penetration portion 22 is further formed in the small penetration portion 30. The penetration portion 22 is formed to a size that allows the formation of the insertion port 16, as described in Modification 1 of the first embodiment. However, the example in Fig. 10A is just one example, and the formation of the insertion port 16 may be omitted.

[0070] Examples of methods for forming the small through-holes 30 include a method of forming by cutting the paper-based substrate 14, a method of forming by punching the paper-based substrate 14, and a method of forming by subjecting the paper-based substrate 14 to corona discharge treatment.

[0071] [2-2 Actions and Effects] According to the lid body 10 of the second embodiment, the same effects as those of the first embodiment can be obtained.

[0072] [2-3 Variations] (Variation 1) According to the lid 10 of the second embodiment, the edge portion of the small through hole 30 may have a portion that extends toward the opposing surface 73 (Variation 1). The lid 10 of Variation 1 of the second embodiment can be realized by making an incision by inserting a breaking blade from the exposed surface 72 side to the opposing surface 73 side of a blank material for forming the lid 10, and the incision is formed as the small through hole 30. In other words, when an incision is made by inserting a breaking blade from the exposed surface 72 side to the opposing surface 73 side, a burr is generated toward the opposing surface 73 side, and this burr (burr portion) forms the edge portion of the small through hole 30 that extends toward the opposing surface 73 side.

[0073] According to the cover body 10 of the first modified example of the second embodiment, the portion of the edge of the small penetration portion 30 extending toward the opposing surface 73 can function as a spacer to maintain the gap 18 between the second paper-based substrate 14B and the first paper-based substrate 14A.

[0074] (Variation 2) According to the lid 10 of the second embodiment, the edge portion of the small through hole 30 may have a portion that extends toward the exposed surface 72 (Variation 2). The lid 10 of Variation 2 of the second embodiment can be realized by making an incision by inserting a breaking blade from the opposing surface 73 side to the exposed surface 72 side of a blank material for forming the lid 10, and the incision is formed as the small through hole 30. In other words, when an incision is made by inserting a breaking blade from the opposing surface 73 side to the exposed surface 72 side, a burr is generated toward the opposing surface 73 side, and this burr (burr portion) forms an edge portion of the small through hole 30 that extends toward the opposing surface 73 side.

[0075] According to the cover body 10 of the second embodiment, the portion of the edge of the small penetration portion 30 extending toward the opposing surface 73 can function as a guide path for guiding gas that has reached the gap 18 between the second paper-based substrate 14B and the first paper-based substrate 14A to the outside.

[0076] 3. Third Embodiment [3-1 Configuration] 11A, 11B, and 11C, the lid 10 according to the third embodiment has an overlapping structure 17, and a plurality of small penetration holes 30 are formed in the paper-based substrates 14 other than the paper-based substrate 14 that forms the overlapping structure 17 and that is arranged closest to the exposed surface 72. The lid 10 according to the third embodiment has the same configuration as the first and second embodiments except for the configuration in which the small penetration holes 30 are formed. Furthermore, variations 1 to 4 of the first embodiment may also be applied to the third embodiment, as in the second embodiment.

[0077] In the example of Fig. 11, the overlapping structure 17 has a structure in which a first paper-based substrate 14A and a second paper-based substrate 14B are overlapped. A small through hole 30 is formed in the first paper-based substrate 14A on the top surface 11 of the lid 10. As shown in Fig. 2C, the overlapping structure 17 has a gap 18 formed between the first paper-based substrate 14A and the second paper-based substrate 14B.

[0078] (Small penetration) The small through-hole 30 is similar to the small through-hole described in the second embodiment, and therefore a detailed description thereof will be omitted.

[0079] In the lid 10 according to the third embodiment, as described in the second embodiment, a penetration portion 22 may be further formed in the small penetration portion 30, or the penetration portion 22 may be omitted, as shown in FIG. 11A . However, in the lid 10 according to the third embodiment, when the penetration portion 22 is formed, unlike the second embodiment, it is preferable that the paper-based substrate 14 forming the penetration portion 22 is different from the paper-based substrate 14 forming the small penetration portion 30. As described in Modification 1 of the first embodiment, the penetration portion 22 is preferably formed in the second paper-based substrate 14B. The penetration portion 22 is formed to a size that allows the insertion opening 16 to be formed. By differentiating the paper-based substrate 14 forming the penetration portion 22 from the paper-based substrate 14 forming the small penetration portion 30, it is easy to maintain the strength of the paper-based substrate 14 forming the overlapping structure 17. Furthermore, by providing the penetration portion 22 in the paper-based substrate 14 closest to the exposed surface 72, the visibility of the insertion opening 16 can be improved. Furthermore, when the through holes 22 are formed, it is preferable that a partial adhesive section 20 is further formed between the area where the small through holes 30 are formed and the area where the through holes 22 are formed in a plan view of the lid 10, and that the area where the small through holes 30 are formed and the area where the through holes 22 are formed are separated by the further formed partial adhesive section 20. In this case, even when the small through holes 30 are formed with a size that allows liquid to easily enter the gap 18, it is possible to prevent liquid from leaking out through the small through holes 30 in the first paper-based base material 14B and passing through the through holes 22.

[0080] [3-2 Actions and Effects] According to the lid body 10 of the second embodiment, the same effects as those of the first embodiment can be obtained.

[0081] [4. Application Examples] When the lids according to the first to third embodiments are used, the lids can be used in a lidded container 150 as shown in FIGS. 12A and 12B. Here, an example will be described in which the lid 10 according to the first embodiment is used in a lidded container 150. FIG. 12A is a diagram showing an example in which the lid 10 according to the first embodiment is attached to an edge 103 that forms the outer periphery of an opening 102 of a container 101 having an opening 102 formed at its upper end. This example shows an example in which the lid 10 is bonded to the edge 103. FIG. 12B is a cross-sectional view schematically showing the state of the vertical cross section taken along line HH in FIG. 12A. The explanation of the lidded container 150 will continue with reference to FIGS. 12A and 12B.

[0082] (Container with lid) The lidded container 150 has a contact area 151 where the container 101 and the lid 10 come into contact, and the area of ​​the lid 10 that forms the contact area 151 is the bonding area R. In the lidded container 150, the lid 10 can be attached to the container 101 by adhering it to the container 101 in the bonding area R that forms the contact area 151. Adhesion methods that can be used include ultrasonic welding and heat sealing. The edge 103 of the container 101 is often formed with a resin coating layer 120, which is generally a resin layer. In such cases, the lid 10 and the container 101 can be joined using ultrasonic welding, heat sealing, or other methods without the need for an adhesive agent between the lid 10 and the container 101. However, this does not prohibit the contact area 151 where the lid 10 and the container 101 come into contact from being formed by adhering the lid 10 and the container 101 with an adhesive agent (e.g., starch glue) between them. In addition, the resin coating layer 120 is often formed on the inner peripheral surface 106 of the container body 110 as well as on the upper surface of the rim portion 103 .

[0083] The container 101 has a container body 110 having a cylindrical side wall 104 whose diameter increases upward (tapering downward), a bottom 107, and an internal space 105. The container 101 has an opening 102 that opens at the upper end of the container body 110 (the upper end of the side wall 104). Although not shown, the opening 102 of the container 101 is formed in a circular shape. However, the container 101 shown here is an example and is not intended to limit the configuration of the container 101. For example, the opening 102 of the container 101 may be formed in a rectangular shape. The container 101 may be any container as long as the opening 102 can be covered with the lid 10. In such a case, however, it is preferable that the shape of the lid 10 be a shape that matches the shape of the container 101 (e.g., a rectangular shape).

[0084] 15A, 15B, etc., the edge 103 of the opening 102 has a flange portion. The flange portion may be a curled portion 108 formed by outwardly winding a member forming the container body 110, or may be formed as a portion (a flange portion) extending outward on a plane.

[0085] The contents stored inside container 101 (space 105) are not particularly limited, and examples include liquids, solids containing a liquid, liquids mixed with or dissolved in gas (such as carbonated water), and combinations thereof, but the lid of the present invention is particularly effective when the contents contain (or include in the contents) a mixed fluid containing a gas and a liquid. That is, when a fluid such as a liquid is contained, the mixed fluid may be blown outward from the opening of the container, causing the problem of the liquid constituting the mixed fluid leaking from inside the container.

[0086] In the lidded container 150, the lid has a stacked structure formed from multiple paper-based materials, and each paper-based material has a gas ventilation path, so even if the internal pressure inside the container increases, gas can be appropriately released from inside the container to the outside.

[0087] In the above explanation, a container with a lid was described as an example in which the container and lid are bonded together using the resin coating layer of the container, but the container and lid may also be bonded together by placing a resin different from the resin coating layer between the container and the lid.

[0088] (Application example 2) The lid 10 according to the present invention may be combined with a container 101 having an opening 102 .

[0089] As explained above, the present invention can be applied to many such aspects. It can also be applied to stores and methods of providing packaging components other than those described above. The lid body according to the present invention has been described in detail above, but the above examples are merely examples of the lid body according to the present invention and are not limited to these. Therefore, modifications may be made as appropriate within the scope of the spirit of the present invention. Furthermore, the configurations of the inventions described above may be used independently of each other, or may be applied in appropriate combination.

[0090] Based on the above description of this specification, the present invention may employ the configurations shown in the following [E1] to [E11]. [E1] The device is configured to be attachable to a container having an opening and an edge portion that forms the opening, and has a top surface portion that covers the opening when attached to the container, The top surface portion has a plurality of paper-based base materials and has a stacked structure in which a plurality of the paper-based base materials are stacked, Each of the plurality of paper-based substrates has a plurality of fibers, When the surface of the paper-based substrate that directly or indirectly faces the opening of the container is defined as an opposing surface, and the surface opposite to the opposing surface is defined as an exposed surface, the paper-based substrate has a structure in which a plurality of the fibers are crossed to form an air passage path connecting the opposing surface to the exposed surface, The overlapping structure has a partial adhesive portion in which at least two of the paper-based substrates are partially adhesively bonded together. Lid body. [E2] The overlapping structure has a gap between the paper-based substrates facing each other. The lid described in [E1] above. [E3] When the paper substrate arranged closest to the opening of the container is defined as a first paper substrate, and the paper substrate directly facing the first paper substrate is defined as a second paper substrate, The basis weight of the first paper-based substrate is smaller than the basis weight of the second paper-based substrate. The lid according to [E1] or [E2] above. [E4] When the paper substrate arranged closest to the opening of the container is defined as a first paper substrate, and the paper substrate directly facing the first paper substrate is defined as a second paper substrate, The thickness of the first paper-based substrate is smaller than the thickness of the second paper-based substrate. A lid according to any one of [E1] to [E3] above. [E5] When the paper substrate arranged closest to the opening of the container is defined as a first paper substrate, and the paper substrate directly facing the first paper substrate is defined as a second paper substrate, The breathability of the first paper-based substrate is smaller than the breathability of the second paper-based substrate. A lid according to any one of [E1] to [E4] above. [E6] The paper base material has a through hole formed therein that penetrates the paper base material in a thickness direction of the paper base material, and a cross section of the fiber is exposed on an inner peripheral surface of the through hole. A lid according to any one of [E1] to [E5] above. [E7] The partially bonded portion is a portion where at least two of the paper-based substrates are bonded together via an adhesive. A lid according to any one of [E1] to [E6] above. [E8] When the paper-based substrate arranged closest to the opening of the container is a first paper-based substrate, A liquid repellent agent is attached to the first paper substrate. A lid according to any one of [E1] to [E7] above. [E9] The lid described in [E1] above, the container includes a container body having the opening formed at an upper end and a rim portion that forms an outer periphery of the opening, a joint portion at which the lid body is joined to the container; Container with lid. [E10] a resin coating layer is provided on the inner circumferential surface of the container body, The joint portion is an adhesive portion that bonds the container body and the lid body via the resin coating layer. The container with a lid according to [E9]. [E11] The lid described in [E1] above, the container having the opening formed at the top end and a rim forming an outer periphery of the opening; A combination of a lid and a container. [Explanation of symbols]

[0091] 10: Lid 11:Top section 12: Outer edge 14:Paper base material 14A: First paper substrate 14B: Second paper substrate 15: Fiber 16: Entrance 17: Superimposed structure 18: Gap 19: Space 20:Partially bonded part 21: Adhesive 22: Penetration 23: Grip part 30: Small penetration 44: Liquid repellent 72: Exposed surface 73: Opposite surface 95A: Joint area 95B: Lid area corresponding part 95C: Outer area corresponding part 101: Container 102: Opening 103: Edge 104: Side wall 105: Spatial part 106: Inner peripheral surface 107: Bottom 108: Curl section 110: Container body 120: Resin coating layer 150: Container with lid 151: Contact part FG: Arrow FL: Arrow R: Junction area XS1:Area

Claims

1. The device is configured to be attachable to a container having an opening and an edge portion that forms the opening, and has a top surface portion that covers the opening when attached to the container, The top surface portion has a plurality of paper-based base materials and has a stacked structure in which a plurality of the paper-based base materials are stacked, Each of the plurality of paper-based substrates has a plurality of fibers, When the surface of the paper-based substrate that directly or indirectly faces the opening of the container is defined as an opposing surface, and the surface opposite to the opposing surface is defined as an exposed surface, the paper-based substrate has a structure in which a plurality of the fibers are crossed to form an air passage path connecting the opposing surface to the exposed surface, The overlapping structure has a partial adhesive portion in which at least two of the paper-based substrates are partially adhesively bonded. Lid body.

2. The overlapping structure has a gap between the paper-based substrates facing each other. The lid according to claim 1 .

3. When the paper-based substrate arranged at a position closest to the opening of the container is defined as a first paper-based substrate, and the paper-based substrate directly facing the first paper-based substrate is defined as a second paper-based substrate, The basis weight of the first paper-based substrate is smaller than the basis weight of the second paper-based substrate. The lid according to claim 1 or 2.

4. When the paper-based substrate arranged at a position closest to the opening of the container is defined as a first paper-based substrate, and the paper-based substrate directly facing the first paper-based substrate is defined as a second paper-based substrate, The thickness of the first paper-based substrate is smaller than the thickness of the second paper-based substrate. The lid according to claim 1 or 2.

5. When the paper-based substrate arranged at a position closest to the opening of the container is defined as a first paper-based substrate, and the paper-based substrate directly facing the first paper-based substrate is defined as a second paper-based substrate, The air permeability of the first paper-based substrate is smaller than the air permeability of the second paper-based substrate. The lid according to claim 1 or 2.

6. The paper base material has a through hole formed therein that penetrates the paper base material in a thickness direction of the paper base material, and a cross section of the fiber is exposed on an inner peripheral surface of the through hole. The lid according to claim 1 or 2.

7. The partially bonded portion is a portion where at least two of the paper-based substrates are bonded together via an adhesive. The lid according to claim 1 or 2.

8. When the paper-based substrate arranged closest to the opening of the container is defined as a first paper-based substrate, A liquid repellent agent is attached to the first paper substrate. The lid according to claim 1 or 2.

9. The lid according to claim 1; the container includes a container body having the opening formed at an upper end and a rim portion that forms an outer periphery of the opening, a joint portion at which the lid body is joined to the container; Container with lid.

10. a resin coating layer is provided on the inner circumferential surface of the container body, The joint portion is an adhesive portion that bonds the container body and the lid body via the resin coating layer. The container with lid according to claim 9.

11. The lid according to claim 1; the container having the opening formed at the top end and a rim forming an outer periphery of the opening; A combination of a lid and a container.

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