Pulp molded lid

Abstract

To provide a pulp-molded lid body that deformation is to less take place and a content of a container is to less leak even if mating with and unmating from the container are repeated.SOLUTION: A pulp-molded lid body 100 comprises a top portion 10 and an outer peripheral edge portion 30 and is allowed to mate with and unmate from an opening end 3 of a container 1. A density of the lid body 100 is 0.40 g / cm3 or higher, an average thickness of the lid body 100 is 0.25 mm or greater and 1.50 mm or smaller, and a pulp material of the pulp-molded lid body contains virgin pulp of 80 mass% or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to a pulp molded lid. [Background technology]

[0002] Conventionally, container lids have often been made of plastic from the viewpoint of cost, etc. For example, Patent Document 1 describes a plastic molded lid with an inner seal that is fitted over a cup-shaped or tray-shaped plastic molded container and sealed by heat-sealing an inner seal material to a flange on the upper periphery, characterized in that the inner seal material is laminated on the inner side of the plastic molded lid via a peelable layer, and then vacuum or pressure molded. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2007-84075 A Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, marine pollution caused by plastics has become a problem, and there is a demand for the development of pulp molded products using pulp raw materials that do not use plastics. Pulp molded products are formed using a cutting mold and a press drying mold, and are suitable for use as environmentally friendly industrial packaging materials and food containers that are easy to recycle. However, when pulp molded products are used as container lids, they are prone to deformation due to the increased number of times they are engaged and disengaged with the container, which can cause the contents of the container to leak.

[0005] An object of the present invention is to provide a pulp molded lid which is resistant to deformation even when repeatedly engaged and disengaged with a container, and which is resistant to leakage of the contents of the container. [Means for solving the problem]

[0006] As a result of intensive research into solving the above-mentioned problems, the inventors have discovered that by having the following configuration, it is possible to provide a pulp-molded lid that is less likely to deform even when repeatedly engaged and disengaged with a container, and that is less likely to leak the contents of the container. That is, the present invention provides the following: <1> ~ <11> Regarding. <1> A pulp molded closure having a top and a peripheral edge depending from the peripheral edge of the top, which can be fitted to and unfitted from an open end of a container, the closure having a density of 0.40 g / cm 3 The above, the average thickness of the lid is 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp. <2> The pulp raw material of the pulp molded lid contains 100% by mass of virgin pulp. <1> The pulp molded lid body according to claim 1. <3> The pulp raw material of the pulp molded lid body contains one or more selected from the group consisting of softwood kraft pulp, hardwood kraft pulp, bagasse, and bamboo. <1> or <2> The pulp molded lid body according to claim 1. <4> The pulp raw material of the pulp molded lid body is a mixed pulp of one or more kinds of wood pulp selected from softwood kraft pulp and hardwood kraft pulp, and one or more kinds of non-wood pulp selected from bagasse and bamboo. <1> ~ <3> 13. A pulp molded lid body according to any one of claims 1 to 12. <5> The blending amount of softwood kraft pulp and bagasse in the pulp raw material of the pulp molded lid body is 50% by mass or more. <1> ~ <4> 10. The pulp molded lid body according to claim 9, <6> The Canadian standard freeness of the pulp constituting the pulp molded lid is 100 mL or more and 700 mL or less. <1> ~ <5> 13. A pulp molded lid body according to any one of claims 1 to 12. <7> The pulp molded lid is made of one layer. <1> ~ <6> 10. The pulp molded lid body according to claim 9, <8> The container is a beverage container. <1> ~ <7> 10. The pulp molded lid body according to claim 9, <9> The top portion includes at least one of a mouth and a notch. <1> ~ <8> 10. The pulp molded lid body according to claim 9, <10> The container is a hot beverage container and is intended for hot beverages, <1> ~ <9> 10. The pulp molded lid body according to claim 9, <11> The container is a paper cup. <1> ~ <10> 10. The pulp molded lid body according to claim 9, Effect of the Invention

[0007] According to the present invention, it is possible to provide a pulp molded lid which is less likely to deform even when repeatedly engaged and disengaged with a container, and which is less likely to leak the contents of the container. [Brief description of the drawings]

[0008] [Figure 1] 1 is a schematic vertical cross-sectional view illustrating a pulp molded lid according to a first embodiment. FIG. [Diagram 2] FIG. 1 is a schematic diagram for explaining the state in which the pulp-molded lid body of the first embodiment is fitted to a container, and FIG. 1 is a schematic vertical cross-sectional view illustrating the state in which the pulp-molded lid body of the first embodiment is positioned above a container, and FIG. 1 is a schematic vertical cross-sectional view illustrating the state in which the pulp-molded lid body of the first embodiment is fitted to a container. [Diagram 3] FIG. 1 is a schematic diagram for explaining the state in which the engagement between the pulp-molded lid body and the container in the first embodiment is released, with part (a) in the diagram being a schematic vertical cross-sectional view illustrating a state in which an L-shaped jig is hooked onto the lower end of the outer peripheral edge of the pulp-molded lid body in the first embodiment, and part (b) in the diagram being a schematic vertical cross-sectional view illustrating a state in which the engagement between the pulp-molded lid body and the container in the first embodiment has been released. [Figure 4]FIG. 11 is an external oblique view illustrating a pulp-molded lid body according to a second embodiment, where sub-view (a) is a top external oblique view illustrating a pulp-molded lid body according to the second embodiment, and sub-view (b) is a bottom external oblique view illustrating a pulp-molded lid body according to the second embodiment. [Diagram 5] A side view illustrating a pulp-molded lid body relating to a second embodiment, where part (a) in the figure is a side view illustrating a pulp-molded lid body relating to the second embodiment, and part (b) in the figure is a longitudinal cross-sectional view illustrating a pulp-molded lid body relating to the second embodiment. [Figure 6] FIG. 11 is a top external perspective view illustrating a pulp molded lid according to a third embodiment. [Figure 7] FIG. 13 is a top external perspective view illustrating a pulp molded lid according to a fourth embodiment. [Figure 8] 13 is a plan view of the exterior of a pulp molded lid body according to a fourth embodiment, illustrating the state in which the small lid is fitted into the small lid fitting portion. FIG. [Figure 9] 13 is a plan view illustrating a state in which the small lid and the small lid fitting portion of a pulp molded lid body according to a fourth embodiment are disengaged from each other. [Figure 10] FIG. 8 is an external rear view of the pulp molded lid of FIG. 7. [Figure 11] FIG. 9 is an external rear view of the pulp molded lid of FIG. 8. [Figure 12] 13 is a vertical cross-sectional view illustrating a pulp molded lid body according to a modified example. FIG. [Figure 13] 13 is a vertical cross-sectional view illustrating a pulp molded lid body according to a modified example. FIG. [Figure 14] 13 is a vertical cross-sectional view illustrating a pulp molded lid body according to a modified example. FIG. [Figure 15] 13 is a vertical cross-sectional view illustrating a pulp molded lid body according to a modified example. FIG. [Figure 16] 13 is a vertical cross-sectional view illustrating a pulp molded lid body according to a modified example. FIG. [Figure 17] FIG. 2 is a top perspective view showing an example of a pulp molded lid according to the present embodiment. [Figure 18] FIG. 2 is a top perspective view showing an example of a pulp molded lid according to the present embodiment. [Figure 19] FIG. 2 is a perspective view of a pulp molded lid produced in the examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [Pulp molded lid] The pulp molded lid of the present invention has a top and an outer peripheral edge portion that hangs down from the outer peripheral edge of the top, and is capable of being fitted to and released from the open end of a container, and the density of the lid is 0.40 g / cm 3 The average thickness of the lid is 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp (see, for example, FIG. 2).

[0010] Because the pulp-molded lid of the present invention has a density and average thickness within the above-mentioned ranges, it can be repeatedly engaged and disengaged with a container, and is less likely to deform even when engaged and disengaged repeatedly, thereby preventing the contents of the container from leaking.

[0011] (density) The density of the pulp molded lid of the present invention is set to 0.40 g / cm from the viewpoint of making the pulp molded lid less likely to leak even when repeatedly engaged and disengaged with a container, and from the viewpoint of further improving the surface smoothness and oil resistance. 3 or more, preferably 0.45 g / cm 3 More preferably, 0.50 g / cm 3 More preferably, 0.55 g / cm 3 and preferably 1.0 g / cm 3 Less than or equal to 0.95 g / cm 3 More preferably, 0.90 g / cm 3 More preferably, 0.85 g / cm 3 The following is the result. The density of the pulp molded lid can be measured in accordance with JIS P 8118:2014. Note that JIS P 8118:2014 is a method used for paper and paperboard, and in the present invention, the sample size may not be obtained as specified. In such a case, the sample size is appropriately adjusted and used for measurement. The flat part of the lid is used for measurement.

[0012] (Average thickness) The average thickness of the pulp molded lid is 0.25 mm or more, preferably 0.30 mm or more, more preferably 0.35 mm or more, and even more preferably 0.40 mm or less, and 1.50 mm or less, preferably 1.20 mm or less, from the viewpoint of making the pulp molded lid less likely to leak even if it is repeatedly engaged and disengaged with the container. The average thickness of the pulp molded lid is the arithmetic average value of the thicknesses measured at 10 arbitrary points according to JIS P 8118:2014. As in the above, if the sample size cannot be obtained as specified, the sample size is appropriately adjusted and used for measurement. The flat part of the lid is used for measurement.

[0013] (Basic weight) The basis weight of the pulp molded lid is preferably 200 g / m from the viewpoint of water resistance and strength. 2 More preferably, 250 g / m 2 More preferably, 300 g / m 2 More preferably, 350 g / m 2 and from an economical point of view, preferably 1500 g / m 2 Less than 1000g / m 2 Less than 700 g / m 2 The following is the result. The basis weight of the pulp molded lid is measured in accordance with JIS P 8124:2011. As in the above, if the sample size cannot be obtained as specified, the sample size is appropriately adjusted and used for measurement. The flat part of the lid is used for measurement.

[0014] (Mating and Opening Forces) In order for the pulp-molded lid of the present invention to be both easy to close and easy to open, and to maintain a fitted state under normal use conditions, it is preferable for it to satisfy at least one of the following requirements 1 and 2, and it is more preferable for it to satisfy both requirements 1 and 2. Requirement 1: The pulp molded lid is placed above the open end of the container, horizontally relative to the upper end of the open end, and a load is applied in the vertical direction at a speed of 100 mm / min. The maximum load value when the lid is fitted into the open end of the container, the fitting force (hereinafter simply referred to as the "fitting force" or "fitting shock peak value"), is 0.2 N / cm or more and 6.0 N / cm or less. Requirement 2: An L-shaped jig is hooked onto the lower end of the outer edge of the pulp molded lid that is fitted onto the open end of the container, and pulled up at a speed of 300 mm / min. The opening force, which is the load value when the fitting is released (hereinafter referred to simply as the "opening force" or "opening shock peak value"), is 0.05 N / cm or more and 1.5 N / cm or less.

[0015] <Mating force (requirement 1)> Specifically, the fitting force of the pulp molded lid is measured as follows. First, the pulp molded lid and the container are left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. Then, the pulp molded lid is placed above the open end of the container horizontally to the upper end of the open end, and a load is applied vertically to the upper surface of the pulp molded lid at a speed of 100 mm / min (see the sub-diagram (a) in FIG. 2). The maximum load value (fitting shock peak value) when the pulp molded lid is fitted to the open end of the container is taken as the fitting force (see the sub-diagram (b) in FIG. 2). Here, when applying a load vertically to the upper surface of the pulp molded lid, a plate (for example, a disk-shaped compression tool "PC-5100" manufactured by Imada Co., Ltd.) or the like can be used. Here, "horizontal" refers to a generally horizontal state, and allows for a deviation of about ±5°, for example.

[0016] The fitting force of the pulp molded lid, from the viewpoint of achieving both ease of closing and opening and maintaining the fitted state with the container 1 under normal use conditions, is preferably 0.2 N / cm or more, more preferably 0.4 N / cm or more, even more preferably 0.6 N / cm or more, even more preferably 0.8 N / cm or more, even more preferably 1.0 N / cm or more, and is preferably 6.0 N / cm or less, more preferably 5.5 N / cm or less, even more preferably 5.0 N / cm or less, even more preferably 4.5 N / cm or less, and even more preferably 4.0 N / cm or less.

[0017] When a user presses a pulp-molded lid vertically (towards the container), unlike a plastic lid, it easily fits around the entire opening end of the container, not just part of it, so it closes tightly and prevents the contents of the container from spilling out.

[0018] <Opening ability (requirement 2)> Specifically, the opening force of the pulp molded lid is measured as follows. First, the container fitted with the pulp molded lid is left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. Then, an L-shaped jig is hooked on the lower end of the outer periphery of the pulp molded lid fitted to the open end of the container, and pulled up at a speed of 300 mm / min (see sub-diagram (a) in FIG. 3). Then, the load value (opening shock peak value) when the fitting between the pulp molded lid and the container is released is taken as the opening force (see sub-diagram (b) in FIG. 3). Here, the L-shaped jig used is a chip peeling jig (GT-20) manufactured by Imada Co., Ltd.

[0019] The opening force of the pulp molded lid, from the viewpoint of maintaining a fitting state with the container under normal use conditions and achieving both ease of closing and ease of opening, is preferably 0.05 N / cm or more, more preferably 0.15 N / cm or more, even more preferably 0.25 N / cm or more, and is preferably 1.5 N / cm or less, more preferably 1.4 N / cm or less, even more preferably 1.3 N / cm or less, and even more preferably 1.2 N / cm or less.

[0020] <Pulp raw material> Examples of the pulp raw material for the pulp molded lid of the present invention include wood pulp, non-wood pulp, and waste paper, and wood pulp and non-wood pulp are preferred, and a mixed pulp of wood pulp and non-wood pulp is more preferred. Here, the pulp raw material is the pulp that constitutes the pulp molded lid. Examples of wood pulp include wood pulp that is generally used for papermaking purposes, and depending on the preparation method, it is classified into chemical pulps such as kraft pulp (KP), sulfite pulp (SP), and soda pulp (AP); semi-chemical pulps such as semi-chemical pulp (SCP) and chemi-ground wood pulp (CGP); and mechanical pulps such as groundwood pulp (GP), thermomechanical pulp (TMP, BCTMP), and refiner ground wood pulp (RGP); and the like. Examples of wood pulp include coniferous pulp and hardwood pulp, depending on the raw material. Examples of coniferous pulp include pulp obtained from the fir and pine genus. Examples of hardwood pulp include pulp obtained from the acacia, eucalyptus, and poplar genus. Among these, coniferous kraft pulp (NKP) and hardwood kraft pulp (LKP) are more preferable as wood pulp. When coniferous kraft pulp is blended, it becomes easier to obtain a lid that is less likely to deform due to external forces and is less likely to leak the contents of the container. Also, when hardwood pulp is blended, it becomes easier to obtain a lid that is excellent in smoothness and has a good feel in the mouth.

[0021] In the present invention, the hardwood pulp is preferably a wood pulp of the Acacia genus or the Eucalyptus genus from the viewpoint of the smoothness of the resulting pulp molded lid. One type of hardwood pulp may be used alone, or two or more types may be used in combination. In the present invention, the coniferous pulp is preferably a coniferous pulp of the genus Pinus, more preferably radiata pine. By including coniferous pulp as the pulp raw material, a pulp molded lid having superior strength can be obtained. The coniferous pulp may be used alone or in combination of two or more kinds.

[0022] From the viewpoint of further improving water resistance and oil resistance, the pulp raw material preferably contains one or more selected from the group consisting of softwood kraft pulp, hardwood kraft pulp, non-wood pulp bagasse, and bamboo. In particular, from the viewpoint of obtaining a lid body that is not easily deformed by external forces and does not easily leak the contents of the container, the pulp raw material preferably contains at least one of softwood kraft pulp and bagasse. In this case, the blending amount of softwood kraft pulp and bagasse in the pulp raw material (the total blending amount when both are blended) is preferably 50% by mass or more, more preferably 75% by mass or more, even more preferably 85% by mass or more, and preferably 100% by mass or less, from the viewpoint of making it difficult for deformation to occur even when repeatedly fitting and disengaging with the container.

[0023] When the pulp raw material is a mixed pulp of wood pulp and non-wood pulp, the content of wood pulp in the pulp raw material is preferably 5 mass% or more, more preferably 10 mass% or more, from the viewpoint of further improving the surface smoothness and oil resistance of the pulp molded lid, and is preferably 95 mass% or less, more preferably 90 mass% or less, even more preferably 80 mass% or less, and even more preferably 55 mass% or less.

[0024] Non-wood pulp is fiber obtained from the bark, stems, leaves, and leaf sheaths of plants.Specific examples include pulp obtained from cotton linters, cotton, linen, hemp, ramie, straw, esparto, Manila hemp, sisal, jute, flax, kenaf, bamboo, bagasse, ganpi, mitsumata, kozo, and mulberry. From the viewpoint of improving the oil resistance of the pulp molded lid, the non-wood pulp preferably contains at least one selected from bagasse and bamboo, more preferably at least one selected from bagasse and bamboo, and even more preferably bagasse. By blending bagasse, it becomes easier to obtain a lid that is less likely to deform due to external forces and is less likely to leak the contents of the container. When the pulp raw material is a mixed pulp of wood pulp and non-wood pulp, the content of non-wood pulp in the pulp raw material is, from the viewpoint of further improving the surface smoothness and oil resistance of the pulp molded lid, preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 20% by mass or more, even more preferably 45% by mass or more, and preferably 95% by mass or less, more preferably 90% by mass or less, even more preferably 85% by mass or less, even more preferably 80% by mass or less, and even more preferably 55% by mass or less. When the pulp raw material is a mixed pulp of wood pulp and non-wood pulp, the non-wood pulp preferably contains at least one selected from bagasse and bamboo, more preferably at least one selected from bagasse and bamboo, and even more preferably bagasse. When the pulp raw material is a mixed pulp of wood pulp and non-wood pulp, the wood pulp is preferably one or more selected from the group consisting of hardwood pulp and softwood pulp, and more preferably hardwood kraft pulp.

[0025] In the present invention, the pulp raw material contains 80% by mass or more of virgin pulp. By making the virgin pulp content 80% by mass or more, a pulp molded lid having more excellent surface smoothness can be obtained. The virgin pulp content in the pulp raw material is more preferably 85% by mass or more, even more preferably 90% by mass or more, still more preferably 95% by mass or more, and is 100% by mass or less, and even more preferably 100% by mass. As the virgin pulp, bleached pulp, semi-bleached pulp, and unbleached pulp are preferred. Furthermore, when mercerized pulp or crosslinked pulp is contained as the pulp raw material, the strength or density of the pulp molded lid tends to decrease. Therefore, the content of mercerized pulp or crosslinked pulp in the pulp raw material is preferably 20% by mass or less, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably none (0% by mass). When recycled paper pulp is contained in a pulp molded lid, the elastic modulus of the lid decreases, and deformation occurs easily when the lid is repeatedly engaged and disengaged with a container, which may cause the contents of the container to leak. In addition, recycled paper pulp tends to have a large amount of residual ink and poor dispersibility. In addition, recycled paper pulp tends to fluff easily, has low whiteness, and has undeinked fibers that look black and long with ink remaining on the pulp fibers, which tends to cause black whiskers. In addition, dust can be seen due to the presence of vinyl that looks gray and black spots remaining. As a result, the content of recycled paper pulp in the pulp raw material for the obtained pulp molded lid is preferably less than 20% by mass, more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably no recycled paper pulp is contained (0% by mass).

[0026] (Canadian Standard Freeness (CSF)) In the present invention, the Canadian standard freeness of the pulp raw material is preferably 100 mL or more, more preferably 150 mL or more, even more preferably 200 mL or more, still more preferably 250 mL or more, and still more preferably 300 mL or more, from the viewpoint of productivity of the pulp raw material and papermaking properties during production of the pulp molded lid, and is preferably 700 mL or less, more preferably 650 mL or less, even more preferably 600 mL or less, still more preferably 550 mL or less, and still more preferably 520 mL or less, from the viewpoint of surface smoothness. The degree of beating may be adjusted so that the Canadian standard freeness falls within the above range. Canadian Standard Freeness is measured in accordance with JIS P 8121-2:2012.

[0027] (tensile modulus) In the present invention, a pulp sheet (e.g., having a basis weight of 60 g / m) made from a pulp raw material is 2 , density 0.50g / cm 3 From the viewpoint of obtaining a lid body that is difficult to deform due to an external force and is difficult for the contents of the container to leak, the tensile modulus of elasticity of the lid is preferably 3.00 GPa or more, more preferably 4.00 GPa or more, and even more preferably 4.10 GPa or more. The upper limit of the tensile modulus is not particularly limited, but is, for example, 7.00 GPa or less, preferably 6.10 GPa or less, and more preferably 6.00 GPa or less. The tensile modulus of the pulp sheet is measured in accordance with JIS P 8113:2006.

[0028] (Klemm water absorption) Pulp sheet made from pulp raw material (e.g., 60g / m 2 , density 0.50g / cm 3 From the viewpoint of obtaining a lid having excellent water resistance, the Klemm water absorbency of the pulp sheet of is preferably 75 mm or less, more preferably 65 mm or less, and even more preferably 60 mm or less. The lower limit of the Klemm water absorbency is not particularly limited, but is, for example, 0 mm or more, preferably 10 mm or more, more preferably 20 mm or more, and even more preferably 25 mm or more. The Klemm water absorbency of the pulp sheet is measured in accordance with JIS P 8141:2004.

[0029] (Oil penetration degree) Pulp sheet made from pulp raw material (e.g., 60g / m 2 , density 0.50g / cm 3 From the viewpoint of obtaining a lid having excellent oil resistance, the oil permeability of the lid is preferably 2 sec or more, more preferably 3 sec or more, and even more preferably 4 sec or more. The upper limit of the oil permeability is not particularly limited, but is preferably 50 sec or less, and more preferably 40 sec or less. The oil permeability of the pulp sheet is measured in accordance with the old JIS P 8130:1994.

[0030] <Other ingredients> The pulp molded lid is formed using the above-mentioned pulp as the main raw material. The pulp molded lid may be formed from 100% pulp, but other materials such as various internal additives can be added in addition to the pulp. Examples of other components include inorganic substances such as talc and kaolin, inorganic fibers such as glass fiber and carbon fiber, synthetic resin powder or fiber such as polyolefin, polysaccharides such as carboxymethylcellulose, sizing agents, wet strength agents, dry strength agents, oil-resistant agents, retention agents, drainage improvers, bulking agents, aluminum sulfate, pH adjusters, pitch control agents, slime control agents, colorants such as pigments, etc. It is preferable to contain a sizing agent as another component.

[0031] Examples of sizing agents include rosin-based sizing agents (for example, acidic rosin-based sizing agents and neutral rosin-based sizing agents), alkyl ketene dimers, alkenyl succinic anhydrides, and styrene-containing polymers such as styrene-(meth)acrylate copolymers, with alkyl ketene dimers being preferred.

[0032] Examples of wet strength agents for internal addition include polyamidoamine-epichlorohydrin resin, epoxidized polyamidopolyamine, dialdehyde starch, urea formaldehyde resin, melamine-formaldehyde, polyacrylamide, methylolated polyacrylamide, polyethyleneimine, and the like. Examples of water repellents include wax emulsions, metal soaps (alkali salts of sodium, potassium, zinc, lithium, magnesium, etc.), fatty acid chromium complex salts (myristic complex salts, stearic acid chromic chloride complex salts, etc.), zirconium water repellents, silicone emulsions, etc. In the case where the pulp molded lid of the present invention contains non-wood pulp, it is possible to improve the oil resistance using only the pulp raw material, and therefore sufficient oil resistance can be obtained even if the amount of wet strength agent and water repellent agent added is reduced or not added at all. However, this does not exclude the addition of a wet strength agent or water repellent agent in order to obtain higher oil resistance and water resistance.

[0033] The pulp-molded lid of the present invention may be made of multiple layers by repeating the papermaking process described below multiple times or by hot pressing multiple molded intermediate bodies in a hot pressing process; however, from the viewpoint of superior surface smoothness and oil resistance, a single-layer structure is preferred.

[0034] The container is not particularly limited as long as it can accommodate the contents, but is preferably a food container or a beverage container, more preferably a beverage container, and even more preferably a hot beverage container. Examples of beverage containers include cups made of plastic (e.g., thermoplastic resins such as PET (e.g., C-PET), PP, PE, and PS; biodegradable plastics; natural material mixed plastics), polystyrene foam, and paper (e.g., fine paper and pulp mold), and more preferably a paper cup. The container preferably has an open end that is curled outward.

[0035] When the container is a beverage container, the pulp molded lid of the present invention preferably has at least one of a drinking spout and a notch at the top. The drinking spout may also be provided with a small lid that can be disengaged via a hinge (see Figs. 7 to 11). From the viewpoint of handling, the small lid preferably has a handle for hooking fingers at least on the side opposite the hinge (see Figs. 7 to 11).

[0036] <Secondary processed pulp molded lid> The pulp molded lid of the present invention may be surface-treated to form a secondary processed pulp molded lid. In the present invention, the secondary processed pulp molded lid is a pulp molded lid that has been surface-treated. The pulp molded lid of the present invention has an advantage that it can be easily surface-treated because of its excellent surface smoothness. The method of secondary processing is not particularly limited as long as it is a method that can process the surface of the pulp mold, but it is preferable that the secondary processed pulp mold lid is surface-treated by at least one of the surface treatment methods of direct printing, lamination, transfer, and vapor deposition, more preferably by at least one of the surface treatment methods of direct printing, lamination, and transfer, even more preferably by at least one of the surface treatment methods of lamination and transfer, and even more preferably by at least one of the surface treatment methods of vacuum lamination and hot stamp transfer, which will be described later. However, the method is not limited to these, and a pre-printed sticker or the like may be affixed.

[0037] (Direct printing method) The direct printing method involves applying ink or resin directly to the surface of a pulp-molded lid for the purpose of imparting color, design, pattern, etc., or for the purpose of imparting waterproofness, moisture resistance, etc. Examples of the direct printing method include methods of surface-treating a pulp-molded lid by impregnation, printing, etc. The printing may be performed by any printing means such as letterpress printing using a rubber or resin plate, silk screen printing, pad printing, electrostatic printing, thermal transfer printing, etc. By printing, patterns, letters, etc. can be provided on the surface of the obtained pulp molded lid body. Alternatively, the resin may be directly applied to the pulp molded lid by brushing, spraying, etc. Among these, spray application is preferred from the viewpoint of uniformly applying the resin, etc. The spray application may be performed by any of air spray, airless spray, electrostatic spray, etc. When making the surface of the pulp molded lid waterproof or moisture-proof, it is sufficient to coat it with a water-based emulsion paint containing a resin such as an acrylic resin, a styrene resin, a urethane resin, a melamine resin, an olefin resin, an epoxy resin, a polyvinyl alcohol resin, or a vinylidene chloride resin as a solid content, or an aqueous solution paint or an organic solvent-based paint of these resins.

[0038] (Lamination method) The lamination is preferably performed by covering with a resin film, and examples of the resin film used include polyolefin resins such as polyethylene, polypropylene, and polymethylpentene, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, polyamide resins such as nylon, polyvinyl resins such as polyvinyl chloride, styrene resins such as polystyrene, thermoplastic resin films such as ethylene-vinyl alcohol copolymers and polyacrylonitrile, and biodegradable resin films such as modified polyethylene terephthalate and aliphatic polyester. Considering the manufacturing cost and moldability, polyolefin resins are preferred, and from the viewpoint of environmentally friendly disposal, biodegradable resin films are preferred. The lamination may be formed by laminating two or more of these resin films. The thickness of the resin film is not particularly limited, but is preferably 10 μm or more and 300 μm or less.

[0039] By laminating the above-mentioned resin film, functions such as water resistance, oil resistance, and gas barrier properties can be improved or imparted. Furthermore, a pattern may be printed on the resin film to be laminated in advance, or colored pigments, fine particles (pearl pigments, holograms, etc.), luminous dyes, luminous pigments, etc. may be added. By using such a resin film, it is possible to impart gloss and design to the surface of the pulp molded lid.

[0040] The lamination process may be performed on the pulp molded lid by a known method such as extrusion lamination, heat lamination, dry lamination, or wet lamination. Among these, heat lamination is preferred, vacuum lamination and vacuum pressing are preferred, and vacuum lamination is more preferred. Vacuum lamination may be performed by deforming a sheet placed on top of the substrate by suction from the substrate side (pulp mold side), or by dividing upper and lower chambers, which have already been evacuated, into two by a resin film, and laminating onto the substrate (pulp mold lid) placed in the lower chamber by applying compressed air to the upper chamber, which is equipped with a resin film heating device. In addition, vacuum pressing involves sucking silicone rubber or the like into the substrate (pulp mold lid) side by vacuum, and in some cases applying compressed air from above to deform the material into the shape of the substrate, and the resin film sandwiched between the silicone rubber or the like and the substrate is laminated to the substrate by the pressure of the silicone rubber. Alternatively, the resin film may be preformed in a mold to match the shape of the pulp molded lid, and then laminated to the pulp molded lid.

[0041] The lamination process may be carried out by a conventionally known method, and an example of a vacuum lamination device is a TOM molding machine (manufactured by Fuse Vacuum Co., Ltd.). The conditions for lamination, such as temperature and pressure, may be appropriately selected depending on the material and thickness of the resin film to be laminated, the shape of the substrate, the presence or absence of an adhesive, etc. For example, lamination is performed with a heater heating temperature of 80°C or higher and 200°C or lower.

[0042] During lamination, an adhesive may or may not be applied between the resin film and the pulp molded lid. The adhesive may be a polyurethane adhesive, a polyacrylic adhesive, a polyester adhesive, an epoxy adhesive, a polyvinyl acetate adhesive, a cellulose adhesive, or any other adhesive for lamination. When an adhesive is applied, a pigment having coloring properties, a pearl pigment, fine particles (such as holograms), a luminous pigment, a luminous dye, or the like may be added to the adhesive.

[0043] (Transfer method) Examples of the transfer method include hot stamp transfer, in-mold transfer, hydraulic transfer, and the like, and may be either a dry transfer method or a wet transfer method. In the in-mold transfer method, a preforming step may be added. Among the transfer methods, the hot stamp transfer method (hereinafter, simply referred to as the "hot stamp method") is preferred. The hot stamp method is a method in which a film on which metal is vapor-deposited or a pigment is applied, called "foil," is used, and thermal transfer is performed on a substrate via a thermal adhesive layer provided on the surface of the foil. The foil used in the hot stamp method is laminated in the order of a base film having releasability (for example, a biaxially oriented polyester film), a peeling layer (protective layer), a pattern layer or a vapor-deposition layer, and a thermal adhesive layer, and a release layer is provided between the base film and the protective layer as necessary. Examples of the hot stamp method include (i) the up-down method and (ii) the roll transfer method, and the principle is the same that the pattern layer or vapor-deposition layer in the part where heat pressure is present is transferred to the substrate (pulp molded lid body). In the up-down method, a template with a built-in heater is pressed against the substrate from the base film side, and the pattern layer or vapor-deposition layer is transferred to the substrate via the thermal adhesive layer. Similarly, in the roll transfer method, a heated roller is pressed against the substrate from the base film side to transfer the pattern layer or vapor-deposition layer to the substrate. It is also possible to apply a grinding process, gloss treatment, unevenness processing, etc. to the base film side to impart a shape (to impart unevenness) to the design layer and vapor deposition layer at the time of transfer.

[0044] (Vapor deposition) The vapor deposition may be any vapor deposition method known in the art, and may be either physical vapor deposition or chemical vapor deposition, but is not particularly limited. Vacuum vapor deposition, which is a type of physical vapor deposition, is preferred for the purpose of imparting a metallic luster to the pulp molded lid. The deposition material is preferably metals such as aluminum, chromium, zinc, gold, silver, platinum, and nickel, or oxides and fluorides such as SiO2, TiO2, ZrO2, and MgF2. The thickness of the vapor-deposited layer is not particularly limited, but is preferably 0.1 μm or more.

[0045] [Manufacturing method of pulp molded lid] The method for producing the pulp molded lid is not particularly limited, but it is preferable to produce it by a manufacturing method having the following steps 1 to 3 in this order. Step 1: Preparing a pulp suspension Process 2: The papermaking process in which the pulp suspension is passed through a papermaking mold to produce pulp. Step 3: A hot pressing step in which the intermediate mold obtained after the papermaking step is hot-pressed with a first press die and a second press die positioned in the opposite direction to the first press die while heating the intermediate mold. In step 1, a pulp suspension (pulp slurry) is prepared by adding a pulp raw material and other additives such as a sizing agent. The concentration of the suspension (slurry concentration) is preferably 0.1 to 1.5% by mass, more preferably 0.2 to 1.0% by mass, from the viewpoints of surface smoothness, dimensional stability, and productivity.

[0046] Step 2 is a papermaking step in which pulp is papered from a pulp suspension through a papermaking mold. A forming die, such as a wire mesh die with a vacuum-drawn water-permeable structure, is immersed in the pulp suspension, and the pulp suspension is sucked into the forming die to expel water, while at the same time the pulp fibers are laminated and adsorbed onto the die to form a three-dimensional wet paper that is symmetrical to the die. The forming die is then lifted out of the pulp suspension, and the water-absorbed three-dimensional wet paper is subjected to suction dehydration or pressure dehydration. At this time, while continuing to apply vacuum suction to the molding die with the pulp laminated and adsorbed to its surface, a release device with vacuum suction is brought close to the pulp adsorption surface, and the pulp mold intermediate is dehydrated by compressed vacuum suction. After that, the vacuum pressure of the molding die is returned to normal pressure, and the release device is pulled back with the pulp mold intermediate still adsorbed to the release die, thereby releasing it.

[0047] Step 3 is a hot pressing step in which the mold intermediate obtained after the paper-making step is hot-pressed with a first press die and a second press die positioned in the opposite direction to the first press die while being heated. In step 3, the dehydrated pulp molded intermediate obtained in step 2 is transferred to, for example, a first press die for hot pressing, which is made of a porous die. The pulp molded intermediate transferred to the first press die is heated and pressurized by the first press die and a second press die for hot pressing, which is positioned in the opposite direction to the first press die and engages with the first press die, to obtain a predetermined pulp molded lid. It is preferable that at least one of the first press die and the second press die for hot pressing has an electric heater built therein, thereby heating at least one of the first press die and the second press die. Also, the entire die including the first press die and the second press die may be housed in a furnace into which hot air is introduced, so that hot air passes through the inside of the die.

[0048] In step 3 (hot pressing step), the pressure applied during pressing with the first press die and the second press die is preferably 0.1 MPa or more, more preferably 0.3 MPa or more, even more preferably 0.4 MPa or more, and even more preferably 0.6 MPa or more, from the viewpoint of obtaining a pulp molded lid body with excellent surface smoothness, and is preferably 3.0 MPa or less, more preferably 2.0 MPa or less, and even more preferably 1.5 MPa or less, from the viewpoint of power consumption and equipment load.

[0049] In step 3 (hot pressing step), the temperature during hot pressing is preferably 130°C or higher, more preferably 150°C or higher, and even more preferably 170°C or higher, from the viewpoint of obtaining a pulp molded lid body with excellent surface smoothness, and is preferably 280°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower, from the viewpoints of power consumption, equipment load, and suppression of discoloration.

[0050] The pulp molded lid obtained as described above may be further processed by cutting off unnecessary portions and, if necessary, drilling holes, etc., to form, for example, at least one of a drinking spout and a cut.

[0051] Preferred embodiments for carrying out the present invention will be described below with reference to the drawings. Note that the following embodiments do not limit the inventions according to the claims, and all of the combinations of features described in the embodiments are not necessarily essential to the solution of the invention.

[0052] First, a pulp molded lid 100 according to a first embodiment will be described with reference to Figs. 1 to 3.

[0053] [Pulp molded lid according to the first embodiment] As shown in Figs. 1 to 3, the pulp molded lid 100 according to the first embodiment has a top 10 and an outer peripheral edge 30 that hangs down from the outer peripheral edge of the top 10, and is a pulp molded lid 100 that can be fitted to and released from the open end 3 of a container 1, and the density of the lid is 0.40 g / cm 3 The lid has an average thickness of 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp.

[0054] Top 10 is the part that is farthest from bottom end 31 of outer peripheral edge 30 of pulp molded lid 100, i.e., the highest part of pulp molded lid 100, and is the part that covers the opening of container 1. Top 10 may have a step or the like depending on the use of container 1, etc. A concave-convex pattern can be formed on top 10 by a mold, laser, etc. used for molding. Furthermore, when container 1 that fits with pulp molded lid 100 is a beverage container, top 10 preferably has at least one of a drinking spout and a slit, not shown. A straw or the like can be inserted into the slit.

[0055] The outer peripheral edge portion 30 is a portion that hangs down from the outer peripheral edge of the top portion 10, and constitutes the outer peripheral side surface of the pulp molded lid 100. In this embodiment, the inner peripheral side of the outer peripheral edge portion 30 is configured to have a protrusion 33 that fits with the opening end 3 of the container 1. The outer peripheral edge portion 30 may be provided with a step, a flange, or the like, depending on the application of the container 1. The outer peripheral edge portion 30 can also be formed with an uneven pattern using a mold, laser, or the like used for molding. In addition, the outer peripheral edge portion 30 may have a protrusion or a recess on the outer peripheral side, or may have a protrusion and a recess.

[0056] The protrusion 33 may protrude from the outer peripheral edge 30 toward the inside of the pulp molded lid 100 so as to be able to fit with the opening end 3 of the container 1. The protrusion 33 may be solid, may be hollow in a vertical cross-sectional view, or may be formed by protruding the inner peripheral side of a groove formed by recessing the outer peripheral edge 30 from the outer peripheral side. The protrusion 33 may be formed in one continuous line around the inner circumference of the outer peripheral edge 30, or may be formed in two or more lines. In addition, the protrusions 33 may be formed in multiple lines on the inner peripheral side of the outer peripheral edge 30, and may be discontinuous and arranged in a broken line, or may be formed only on a part of the inner circumference of the outer peripheral edge 30, for example, may be arranged at half the inner circumference of the outer peripheral edge 30. The fitting force and opening force of the pulp molded lid 100 described later can be adjusted by adjusting the height H and width W of the protrusion 33 according to the shape of the opening end 3, etc. (see FIG. 1). Furthermore, even if the pulp molded lid 100 made using the above-mentioned pulp raw material or manufactured by the above-mentioned manufacturing method does not have a convex portion 33, i.e., the height H and width W of the convex portion 33 are zero, it can fit tightly with the container without leaving any gaps due to its ability to moderately absorb liquids, etc.

[0057] The pulp-molded lid 100, placed above the container 1, is pressed vertically (in the direction of the arrow in the exploded view (a) of Figure 2), so that the opening end 3 of the container 1 climbs over the protrusion 33 of the pulp-molded lid 100, allowing the opening end 3 of the container 1 and the protrusion 33 of the pulp-molded lid 100 to fit together (see the exploded view (b) of Figure 2).

[0058] In addition, when the user hooks a finger or the like on the lower end 31 of the outer peripheral edge 30 of the pulp molded lid 100 engaged with the container 1 and pulls it up (see partial view (a) in Figure 3), the protrusion 33 climbs over the opening end 3 of the container 1, and the engagement with the container 1 is released (see partial view (b) in Figure 3).

[0059] The pulp molded lid 100 according to the first embodiment has been described above. Next, the pulp molded lid 110 according to the second embodiment will be described with reference to Figures 4 and 5. Configurations that are the same as or similar to those in the above-mentioned embodiment will be given the same reference numerals and descriptions thereof may be omitted.

[0060] [Pulp molded lid according to the second embodiment] As shown in Figs. 4 and 5, a pulp molded lid 110 according to the second embodiment has a top portion 10 and an outer peripheral edge portion 30 that hangs down from the outer peripheral edge of the top portion 10, and can be fitted to and disengaged from the open end of a container (not shown). The density of the lid is 0.40 g / cm 3 The lid has an average thickness of 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp.

[0061] The top 10 of the pulp molded lid 110 according to the second embodiment is configured to include inclined portions 11 and 12 and a recessed step portion 15 that is recessed and has a step.

[0062] The inclined portions 11 and 12 are arranged to form a recessed step portion 15. The inclined portions 11 and 12 according to the second embodiment are configured to include a first inclined portion 11 and a second inclined portion 12. The first inclined portion 11 and the second inclined portion 12 have different inclinations, but the inclinations may be the same or may change midway. In addition, the inclined portions 11 and 12 may have only the first inclined portion 11 and may not have the second inclined portion 12, and the number of the inclined portions 11 and 12 may be appropriately changed. The first inclined portion 11 or the second inclined portion 12 may be perpendicular to the recessed step portion 15. In addition, the first inclined portion 11 and the second inclined portion 12 may have a curved portion having a curved shape.

[0063] The recessed step portion 15 according to the second embodiment is preferably recessed to a depth at which a convex portion 33 on the inner circumferential side of the outer peripheral edge portion 30, which will be described later, faces the inclined portions 11 and 12. With this configuration, the open end of the container (not shown) of the pulp molded lid 110 is guided and supported by the inclined portions 11 and 12, and overcomes the convex portion 33 to be fitted thereto. Even after the fitting is completed, the inclined portions 11 and 12 support the open end of the container (not shown), so that the fitting state with the container becomes stronger. In this embodiment, the recessed step portion 15 is provided, but multiple recessed step portions may be provided. When multiple recessed step portions are provided, multiple inclined portions are formed to form the recessed step portion.

[0064] The outer peripheral edge portion 30 of the pulp molded lid 110 in the second embodiment is configured to include a convex portion 33 that fits into the open end of a container not shown, a groove portion 34 that is recessed from the outer periphery, a brim-shaped flange portion 35 that extends outward from the lower end 31 of the outer peripheral edge portion 30, and a chamfered portion 37.

[0065] In this embodiment, the inner peripheral surface side of the groove 34 is a convex portion 33. That is, the inner peripheral side of the groove 34, which is formed by recessing the outer peripheral side of the outer peripheral edge portion 30, protrudes to form the convex portion 33. This convex portion 33 fits into the open end of a container (not shown). In this embodiment, the outer peripheral edge portion 30 has a plurality of grooves 34 (convex portions 33), and the grooves 34 (convex portions 33) are arranged at equal intervals and discontinuously so that the distance from the upper end or lower end of the outer peripheral edge portion 30 is constant. Also, in this embodiment, the grooves 34 (convex portions 33) are configured to have a rectangular shape. However, the shapes and arrangement positions of the grooves 34 and the convex portions 33 are not limited to this. As in the above-described embodiment, the pulp molded lid 100 manufactured using the above-described pulp raw material or by the above-described manufacturing method can fit tightly to the container without leaving any gaps, even if it does not have a convex portion 33, i.e., even if the height H and width W of the convex portion 33 are zero, due to its ability to absorb liquid appropriately.

[0066] By providing flange portion 35, when a user of pulp molded lid body 110 releases the engagement between pulp molded lid body 110 and a container (not shown), the user's fingers can easily catch on flange portion 35, making it easier to open pulp molded lid body 110.

[0067] When the chamfered portion 37 is formed on the pulp molded lid 110, the edges are eliminated, so that the pulp molded lid 110 has an overall rounded impression, which has the effect of providing excellent design.

[0068] The pulp-molded lid 110 of the second embodiment can also be pressed vertically from above the pulp-molded lid 110 (see the arrow in the partial view (a) of Figure 2), so that the opening end of a container (not shown) overcomes the protrusion 33 of the pulp-molded lid 110 and engages with the protrusion 33 of the pulp-molded lid 110, thereby being able to fit into a container (not shown).

[0069] In addition, when the pulp molded lid 110 is engaged with a container (not shown), when the user hooks a finger or the like around the lower end 31 of the outer peripheral edge 30 and pulls it up (see partial view (a) in Figure 3), the protrusion 33 climbs over the opening end of the container, and the engagement with the container is released (see partial view (b) in Figure 3).

[0070] The pulp molded lid 110 according to the second embodiment has been described above. Next, the pulp molded lid 120 according to the third embodiment will be described with reference to Fig. 6. Configurations that are the same as or similar to those in the above-mentioned embodiments will be given the same reference numerals and descriptions thereof may be omitted.

[0071] [Pulp molded lid according to the third embodiment] As shown in FIG. 6, a pulp molded lid 120 according to the third embodiment has a top 10 and an outer peripheral edge portion 30 that hangs down from the outer peripheral edge of the top 10, and can be fitted to and disengaged from the open end of a container (not shown). The density of the lid is 0.40 g / cm 3The lid has an average thickness of 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp.

[0072] The top 10 of the third embodiment is configured to include a first inclined portion 11, a first recessed step portion 15A, a second inclined portion 12, a second recessed step portion 15B, a drinking spout 17, two through holes 19, 19, a third inclined portion 13, a third recessed step portion 15C, and a fourth inclined portion 14.

[0073] The first inclined portion 11 is arranged to form a first recessed step portion 15A. The second inclined portion 12 is arranged to connect the first recessed step portion 15A and the second recessed step portion 15B. The third inclined portion 13 and the fourth inclined portion 14 are arranged to form a third recessed step portion 15C. The first inclined portion 11, the second inclined portion 12, the third inclined portion 13, and the fourth inclined portion 14 may be perpendicular to the first recessed step portion 15A, the second recessed step portion 15B, the third recessed step portion 15C, and the third recessed step portion 15C, respectively. In addition, the first inclined portion 11, the second inclined portion 12, the third inclined portion 13, and the fourth inclined portion 14 may not have a constant inclination and may have a curved portion having a curved shape.

[0074] In this embodiment, the drinking spout 17 is configured in a substantially rectangular shape and is located at the top 10 (the highest part of the pulp molded lid body 120), but this can be modified as appropriate. The two through holes 19, 19 are passages for steam and air, and are provided so that the user can smoothly drink a beverage from the drinking spout 17. The through hole 19 is not particularly limited, but is preferably located away from the drinking spout 17. There may be one or more through holes 19, and the number and installation positions can be modified as appropriate. In this embodiment, the two through holes 19, 19 are respectively located at the top 10 (the highest part of the pulp molded lid body 120) and the second recessed step portion 15B.

[0075] In this embodiment, first recessed step portion 15A and second recessed step portion 15B are substantially semicircular when viewed from the direction of use when a user drinks a beverage from drinking spout 17, and first recessed step portion 15A has a cut-out portion disposed on the lower chord, while second recessed step portion 15B has a cut-out portion disposed on the upper chord, but this can be modified as appropriate. Also, in this embodiment, third recessed step portion 15C is configured to extend outward from the lower end of third inclined portion 13 in a brim-like shape, but this can be modified as appropriate.

[0076] The top portion 10 according to the third embodiment is configured to include a third recessed step portion 15C having a brim shape in the columnar portion including the third inclined portion 13, and a fourth inclined portion 14.

[0077] The outer peripheral edge portion 30 of the third embodiment is configured to include a groove portion 34 recessed from the outer peripheral side, a convex portion (not shown) protruding from the inner peripheral side of the groove portion 34, a brim-shaped flange portion 35 extending outward from the lower end 31 of the outer peripheral edge portion 30, and a chamfered portion 37.

[0078] In the pulp molded lid 120 according to the third embodiment, when a load is applied vertically (see the arrow in the divided view (a) in FIG. 2) to the upper surface of the pulp molded lid 120, the opening end of the container (not shown) overcomes the convex portion 33 of the pulp molded lid 120, and the opening end of the container (not shown) can fit into the convex portion 33 of the pulp molded lid 120. As in the above-described embodiment, the pulp molded lid 100 made using the above-described pulp raw material or manufactured by the above-described manufacturing method can fit tightly with the container without leaving a gap, due to its ability to moderately absorb liquid, etc.

[0079] The pulp molded lid 120 according to the third embodiment has been described above. Next, the pulp molded lid 130 according to the fourth embodiment will be described with reference to Fig. 1. Components that are the same as or similar to those in the above-described embodiments will be given the same reference numerals and descriptions thereof may be omitted.

[0080] [Pulp molded lid according to the fourth embodiment] As shown in Figs. 7 to 11, a pulp molded lid 130 according to a fourth embodiment has a top portion 10 and an outer peripheral edge portion 30 that hangs down from the outer peripheral edge of the top portion 10, and can be fitted to and disengaged from the open end of a container (not shown). The density of the lid is 0.40 g / cm 3 The lid has an average thickness of 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp.

[0081] The top portion 10 of the fourth embodiment is configured to include a first inclined portion 11, a first recessed step portion 15A, a second inclined portion 12, a second recessed step portion 15B, a chamfered portion 37, a third inclined portion 13, a flange portion 35, and one through hole 19.

[0082] In this embodiment, the first recessed step portion 15A is configured to include a drinking spout notch 17A cut to form the drinking spout 17, a small lid 41 that can be opened and closed via a hinge portion 43 on the drinking spout 17, and a small lid fitting portion 61 that fits with the small lid 41.

[0083] As shown in Figs. 8 and 10, in this embodiment, the drinking spout 17 is configured to have a substantially square shape.

[0084] The small lid 41 according to this embodiment is formed at a position that becomes the drinking spout 17 when opened via the hinge portion 43. That is, the small lid 41 has the same shape as the drinking spout 17, and in this embodiment, is square. The small lid 41 includes a handle portion 45 for hooking a finger provided on the opposite side of at least the hinge portion 43, a hinge portion recess 47 that is positioned overlapping the hinge portion 43 and is lower than the height of the first recessed step portion 15A, and a square columnar portion 50 (51, 53, 55, 57, 57) that fits into the small lid fitting portion 61 described later.

[0085] The handle portion 45 is formed on the outer periphery of the rectangular columnar portion 50, and the user can hook his / her fingers at any point other than the hinge portion 43.

[0086] The hinge recess 47 can be formed, for example, by crease processing. The provision of the hinge recess 47 makes it easier to open and close the small lid 41. In this embodiment, the width of the hinge recess 47 is the same as the width of the rectangular columnar portion 50. Also, in this embodiment, the drinking spout notch 17A extends to both ends of the hinge recess 47, and the width of the hinge portion 43 is smaller than the width of the hinge recess 47.

[0087] The quadrangular prism 50 according to this embodiment is composed of an inclined portion 51, a vertical portion 53, a rectangular portion 55, and two trapezoidal portions 57, 57, and fits into a small lid fitting portion 61 which will be described later.

[0088] The inclined portion 51 is disposed on the hinge portion 43 side and is configured to be inclined with respect to the first recessed step portion 15A. The vertical portion 53 is disposed on the opposite side of the hinge portion 43 and is configured to extend vertically upward from the handle portion 45. The rectangular portion 55 is disposed between the inclined portion 51 and the vertical portion 53 and is configured to have a rectangular shape. The two trapezoidal portions 57, 57 are disposed adjacent to both ends of the inclined portion 51, the rectangular portion 55, and the vertical portion 53 and are configured to have a second shape.

[0089] It is preferable that the small lid fitting portion 61 has the same shape as the rectangular columnar portion 50, and in this embodiment it is configured with a small lid fitting portion inclined portion 63 corresponding to the inclined portion 51 of the small lid 41, a small lid fitting portion vertical portion 65 corresponding to the vertical portion 53 of the small lid 41, a small lid fitting portion rectangular portion 67 corresponding to the rectangular portion 55 of the small lid 41, and small lid fitting portion trapezoidal portions 69, 69 corresponding to the two trapezoidal portions 57, 57 of the small lid 41.

[0090] The size of the small lid fitting portion 61 is preferably smaller than the size of the rectangular prism portion 50. Specifically, the width of the small lid fitting portion 61 is preferably 0.01 to 1.5 mm smaller than the width of the rectangular prism portion 50, more preferably 0.05 to 1 mm smaller, and even more preferably 0.1 to 0.5 mm smaller. With this configuration, the small lid 41 and the small lid fitting portion 61 can be easily fitted and disengaged from each other.

[0091] When opening the small lid 41 from the state shown in Fig. 7 to expose the drinking spout 17, the user of the pulp molded lid body 130 can, for example, push the vertical portion 53 with a finger to move the square columnar portion 50 near the small lid fitting portion 61, and then hook a finger on the handle portion 45 and press it, thereby fitting the small lid 41 and the small lid fitting portion 61 together as shown in Fig. 8. When closing the small lid 41 from the state shown in Fig. 8 to close the drinking spout 17, the user can hook a finger on the handle portion 45 and pull the small lid 41 up toward the user, i.e., toward the opposite side of the hinge portion 43, thereby releasing the engagement between the small lid 41 and the small lid fitting portion 61, and by further pushing the handle portion 45 or the square columnar portion 50 toward the user (the opposite side of the hinge portion 43) from the state shown in Fig. 9, the drinking spout 17 can be closed as shown in Fig. 7.

[0092] In the pulp molded lid body 130 according to this embodiment, even if the small lid 41 is repeatedly opened and closed, the small lid 41 fits securely into the small lid fitting portion 61, and gaps are unlikely to form when the small lid 41 is moved to a position that closes the drinking spout 17. Therefore, when the user wants to close the drinking spout 17 when moving around, the drinking spout 17 can be closed with few gaps, which has the advantage that the contents of the container are unlikely to spill.

[0093] Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the scope described in the above embodiments. Various modifications and improvements can be made to the above embodiments.

[0094] For example, in the above embodiment, the pulp molded lids 110, 120, 130 are described as being capable of engaging with and disengaging from a container that is circular in plan view, but they may be capable of engaging with and disengaging from a container that is rectangular in plan view, etc. In other words, the tops of the pulp molded lids may be rectangular in plan view, etc.

[0095] Also, for example, in the above-mentioned embodiment, the case where the convex portion 33 is formed in one line around the inner circumference of the outer peripheral edge portion 30, and the case where the convex portion 33 has a rectangular shape and is arranged discontinuously at equal intervals so that the distance from the upper end or the lower end of the outer peripheral edge portion 30 is constant have been exemplified. However, the shape and arrangement position of the convex portion 33 are not limited to this. For example, the convex portion 33 may be a curved line whose distance from the upper end or the lower end of the outer peripheral edge portion 30 is not constant, or may be a discontinuous curved line. Also, the convex portion 33 may have a special shape such as a dogleg shape, an inverted dogleg shape, a U-shape, an inverted U-shape, a C-shape, an inverted C-shape, a U-shape, or an inverted U-shape, or may be a combination of these shapes. That is, when the outer peripheral edge portion 30 has multiple convex portions 33, the convex portions 33 may be the same shape or a combination of different shapes. Also, when the outer peripheral edge portion 30 has multiple convex portions 33, the arrangement intervals between the convex portions 33 do not have to be equal.

[0096] Furthermore, for example, in the above-mentioned embodiment, the convex portion 33 has a generally semicircular shape in vertical cross section, but the shape of the convex portion 33 is not limited thereto. As illustrated in the sub-diagram (a) of FIG. 12, the convex portion may have a triangular shape or a polygonal shape such as a square shape in vertical cross section. Also, as illustrated in the sub-diagram (b) of FIG. 12, the convex portion may have a hook shape in vertical cross section. Furthermore, as illustrated in the sub-diagram (c) of FIG. 12, the convex portion may have undulations, i.e., unevenness.

[0097] Also, for example, in the above-mentioned embodiment, the case where one convex portion 33 is arranged is illustrated, but the arrangement of the convex portion 33 is not limited thereto. As illustrated in FIG. 13, the convex portion may be arranged in two lines, or may be arranged in three or more lines, and the number and arrangement positions can be appropriately changed. FIG. 13 illustrates the case where the convex portion is arranged in two lines so as to have a certain distance from the upper end or the lower end of the outer peripheral edge portion in the vertical cross-sectional view of the pulp molded lid body, but the convex portion may be arranged so as to have a different distance from the upper end or the lower end of the outer peripheral edge portion. Furthermore, the convex portion arranged in two or more lines on the outer peripheral edge portion may be discontinuous, and the shape is not particularly limited, and can be appropriately changed to the above-mentioned shape, etc. Furthermore, the convex portion arranged in two or more lines on the outer peripheral edge portion may be curved or may be a discontinuous curve. Furthermore, as illustrated in FIG. 13, the pulp molded lid body of the present invention may or may not have the above-mentioned groove portion 34. When there are two or more mating shock peak values, the maximum load value (mating shock peak value) is regarded as the mating force.

[0098] Furthermore, for example, in the above-described embodiment, an example was given of the outer peripheral edge portion 30 having a convex portion 33, but as illustrated in Figure 14, the outer peripheral edge portion 30 does not have to have a convex portion 33.

[0099] Also, for example, the pulp molded lid 100 according to the first embodiment has been described with the top 10 being flat, but as shown in the partial view (b) of Fig. 14, the top does not have to be flat, and may be configured in a dome shape that is higher toward the center of the pulp molded lid. Also, the top may be configured to be lower toward the center of the pulp molded lid. In other words, the top may have a height difference.

[0100] Furthermore, as illustrated in FIG. 15, the top may have an inclined portion and a recessed step portion like the pulp molded lid 110 according to the second embodiment. As illustrated in the divided view (a) of FIG. 15, the top may have one inclined portion and one recessed step portion, or as illustrated in the divided views (b) and (c) of FIG. 15, the top may have a plurality of inclined portions and recessed step portions, and the number and arrangement positions thereof can be appropriately changed. In addition, the recessed step portion facing the recessed step portion of the top may be configured to have a linear shape as illustrated in the divided view (b) of FIG. 15, or may have a shape corresponding to the shape of the facing recessed step portion as illustrated in the divided view (c) of FIG. 15, and the shape can be appropriately changed.

[0101] 7 to 11, the pulp molded lid 130 according to the fourth embodiment has a drinking spout and small lid 41 that are substantially square, but the shapes can be changed as appropriate. The shapes of the small lid fitting portion 61 and the square columnar portion 50 are also not particularly limited, as long as the small lid fitting portion 61 and the square columnar portion 50 have corresponding shapes.

[0102] Also, for example, in the above-mentioned embodiment, the thickness of the outer peripheral edge portion 30 is constant, but as illustrated in Fig. 16, the thickness of the outer peripheral edge portion 30 may not be constant. As illustrated in the partial view (a) of Fig. 16, the thickness may be wider toward the lower end of the outer peripheral edge portion 30, or as illustrated in the partial view (b) of Fig. 16, the thickness may be smaller from the upper part to the lower part of the outer peripheral edge portion 30. In other words, the thickness of the outer peripheral edge portion 30 does not have to be constant, and may have a difference. The thickness of the outer peripheral edge portion 30 refers to the thickness of the portion excluding the flange portion 35 if the flange portion 35 is included.

[0103] The pulp molded lid body according to the above-mentioned modified example may have the configuration of the pulp molded lid bodies 100, 110, 120, 130 according to the above-mentioned embodiments, or the pulp molded lid bodies according to other modified examples.

[0104] Specifically, the pulp molded lid body according to the above-mentioned modified example may have, for example, a flange portion 35, a drinking spout 17, a through hole 19, or a notch. Furthermore, for example, the outer peripheral edge portion of the pulp molded lid body illustrated in Figures 12 to 14 may be flared toward the lower end of the outer peripheral edge portion, as in the pulp molded lid body illustrated in partial view (a) of Figure 16, or the thickness may be tapered from the top to the bottom of the outer peripheral edge portion, as illustrated in partial view (b) of Figure 16. Furthermore, for example, the pulp molded lids exemplified in Figures 12 to 14 and Figure 16 may have inclined portions and recessed step portions, and the number and arrangement positions thereof can be changed as appropriate. 14 to 16 show an example in which the outer peripheral edge of the pulp molded lid does not have a protrusion, but this is not limited thereto and the pulp molded lid may have a protrusion. In this case, the shape of the pulp molded lid 100 according to the first embodiment and the shape of the pulp molded lid according to the modified example may be the same, but the shape, number and arrangement of the protrusions are not particularly limited, and the protrusions may have the above-mentioned shapes, may be discontinuous, and may be arranged at different distances from the upper or lower end of the outer peripheral edge. Furthermore, for example, the pulp molded lid shown in FIG. 12 may have two or more protruding rows, or may have two or more discontinuous rows.

[0105] It will be apparent from the description of the claims that such modified or improved forms may also be included within the technical scope of the present invention. EXAMPLES

[0106] The features of the present invention will be described in more detail below with reference to examples and comparative examples. The materials, amounts used, ratios, processing contents, processing procedures, etc. shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention should not be interpreted as being limited by the specific examples shown below.

[0107] [Pulp raw materials] The following pulp raw materials were used to prepare a pulp slurry with a Canadian Standard Freeness (CSF) of 450 mL and a concentration of 0.3% by mass. The basis weight was 60 g / m 2 , density is 0.50g / cm 3 The tensile modulus, Klemm water absorbency, and oil permeability of each pulp sheet were measured. The results are shown in Table 1. The tensile modulus of the pulp sheet was measured in accordance with JIS P 8113:2006. The Klemm water absorbency of the pulp sheet was measured in accordance with JIS P 8141:2004. The smaller the Klemm water absorbency value, the better the water resistance. The oil permeability of the pulp sheet was measured in accordance with the former JIS P 8130:1994. The larger the oil permeability value, the better the oil resistance.

[0108] [Table 1]

[0109] From Table 1, it can be seen that NBKP and bagasse pulp have superior tensile modulus, water resistance, and oil resistance compared to other pulps.

[0110] [Making a pulp molded lid] Example 1 Commercially available LBKP was made into a pulp slurry of 500 mL Canadian Standard Freeness (CSF), and 0.8% by mass of AKD (alkyl ketene dimer, manufactured by Seiko PMC Co., Ltd.) was added as a sizing agent in terms of solid content to 100% by mass of the pulp slurry, and the slurry concentration was adjusted to 0.7% by mass after stirring. In order to remove agglomerates, the slurry was filtered, and a papermaking mold with a metal mesh attached to its surface was immersed in the filtered slurry, and vacuum was applied from inside the mold to suck the pulp slurry onto the mesh, forming a three-dimensional wet paper. The wet paper was transferred to a dewatering mold, dewatered under pressure at a pressure of 0.7 MPa, and then transferred to a mold heated to 180°C, dried under pressure at a pressure of 1.2 MPa, and the excess was cut off, and then punched to obtain a pulp molded lid 200 shown in FIG. 19. The basis weight of the pulp molded lid body 200 is 455 g / m 2 The inner diameter of the pulp molded lid 200 was 80 mm, which was almost the same as the outer diameter of the container (paper cup) used to measure the fitting force and opening force. The depth and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) when the pulp molded lid 200 was fitted to the container (paper cup) was 1.5 N / cm. The opening force (opening shock peak value) of the pulp molded lid 200 when the fitting was released was 0.40 N / cm. The size (outer diameter) of the pulp molded lid was approximately 82 mm, the average thickness was 0.7 mm, and the density was 0.65 g / cm. 3 The same was true for Examples 2 to 6.

[0111] Example 2 A pulp molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 1, except that the Canadian Standard Freeness (CSF) was changed to 350 mL.

[0112] Example 3 A pulp molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 1, except that the commercially available LBKP was changed to commercially available NBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL).

[0113] Example 4 A pulp molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 1, except that the commercially available LBKP was changed to bleached bagasse virgin pulp (Canadian standard freeness (CSF): 450 mL).

[0114] Example 5 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 1, except that a pulp slurry was prepared by mixing 30 parts by mass of commercially available LBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL) and 70 parts by mass of commercially available NBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL).

[0115] Example 6 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 1, except that a pulp slurry was prepared by mixing 10 parts by mass of commercially available LBKP (Canadian standard freeness (CSF) adjusted to 500 mL) and 90 parts by mass of commercially available NBKP (Canadian standard freeness (CSF) adjusted to 500 mL).

[0116] Example 7 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and density were changed to the values ​​shown in Table 2.

[0117] Example 8 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and density were changed to the values ​​shown in Table 2.

[0118] Example 9 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and density were changed to the values ​​shown in Table 2.

[0119] Example 10 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and average thickness were changed to the values ​​shown in Table 2.

[0120] Example 11 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and average thickness were changed to the values ​​shown in Table 2.

[0121] Example 12 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 6, except that the basis weight and average thickness were changed to the values ​​shown in Table 2.

[0122] Example 13 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 1, except that a pulp slurry was prepared by mixing 15 parts by mass of commercially available LBKP (Canadian standard freeness (CSF) adjusted to 500 mL), 70 parts by mass of commercially available NBKP (Canadian standard freeness (CSF) adjusted to 500 mL), and 15 parts by mass of homemade recycled paper pulp (Canadian standard freeness (CSF) adjusted to 500 mL).

[0123] Example 14 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 1, except that a pulp slurry was prepared by mixing 25 parts by mass of commercially available LBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL), 70 parts by mass of commercially available NBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL), and 5 parts by mass of homemade recycled paper pulp (Canadian Standard Freeness (CSF) adjusted to 500 mL).

[0124] Example 15 A pulp slurry was obtained by mixing 30 parts by mass of commercially available LBKP (Canadian Standard Freeness (CSF): adjusted to 500 mL) and 70 parts by mass of commercially available bleached virgin bagasse pulp (Canadian Standard Freeness (CSF): adjusted to 400 mL). AKD (alkyl ketene dimer, manufactured by Seiko PMC Corporation) was added as a sizing agent in an amount of 0.8% by mass (solid content equivalent) to 100% by mass of this pulp slurry, and the slurry concentration was adjusted to 0.7% by mass after stirring. Using this slurry, a pulp molded lid body having the shape shown in FIG. 19 was obtained in the same manner as in Example 1.

[0125] Example 16 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 15, except that 10 parts by mass of commercially available LBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL) and 90 parts by mass of bleached bagasse virgin pulp (Canadian Standard Freeness (CSF) adjusted to 400 mL) were mixed to prepare a pulp slurry.

[0126] Comparative Example 1 A pulp-molded lid having the shape shown in Figure 19 was obtained in the same manner as in Example 1, except that a pulp slurry was prepared by mixing 5 parts by mass of commercially available LBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL), 70 parts by mass of commercially available NBKP (Canadian Standard Freeness (CSF) adjusted to 500 mL), and 25 parts by mass of homemade recycled paper pulp (Canadian Standard Freeness (CSF) adjusted to 500 mL).

[0127] Comparative Example 2 A pulp-molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 5, except that the basis weight and average thickness were changed to the values ​​shown in Table 2.

[0128] Comparative Example 3 A pulp molded lid having the shape shown in FIG. 19 was obtained in the same manner as in Example 5, except that the basis weight and density were changed to the values ​​shown in Table 2.

[0129] [Evaluation and Analysis] The pulp raw materials and the pulp molded lids of the above-mentioned Examples and Comparative Examples were evaluated and analyzed as follows. The results are shown in Table 2.

[0130] <Pulp raw material> (Canadian Standard Freeness (CSF)) The Canadian standard freeness of the pulp raw material constituting the pulp molded lid was measured in accordance with JIS P 8121-2:2012.

[0131] <Pulp molded lid> (Basic weight) The basis weight of the pulp molded lid was measured in accordance with JIS P 8124:2011.

[0132] (Thickness and Density) The thickness and density of the pulp molded lid were measured in accordance with JIS P 8118:2014.

[0133] (Mating Force) The fitting force of the pulp molded lid or plastic lid was measured as follows. First, the pulp molded lid or plastic lid and a container (a commercially available paper cup, outer diameter approximately 80 mm) were left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. Then, the pulp molded lid or plastic lid was placed above the open end of the container horizontally to the upper end of the open end, and a load was applied in the vertical direction at a speed of 100 mm / min (see Figure 2). The maximum load value (fitting shock peak value) when the pulp molded lid or plastic lid was fitted to the open end of the container was taken as the fitting force.

[0134] (Opening force) The opening force of the pulp molded lid or plastic lid was measured as follows. First, a container (commercially available paper cup, outer diameter: about 80 mm) fitted with a pulp molded lid or plastic lid was left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. After that, an L-shaped jig was hooked on the lower end of the outer periphery of the pulp molded lid or plastic lid fitted to the open end of the container, and pulled up at a speed of 300 mm / min (see FIG. 3). Then, the load value (opening shock peak value) when the fitting between the pulp molded lid or plastic lid and the container was released was taken as the opening force.

[0135] (Liquid leakage) The molded pulp lid and container (commercially available paper cup, outer diameter approx. 80 mm, height: 90 mm) produced in each Example and Comparative Example were left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. The molded pulp lid was then placed horizontally above the open end of the container and closed by hand. After standing for 2 minutes, the lid was opened by hand. The same place was always opened by hand, and this action was repeated 50 times to evaluate the following liquid leakage. The container was filled with 80°C hot coffee up to about 15 mm from the top, and the pulp molded lid was fitted. The container was then tilted toward the part that had been opened by hand so that the coffee would flow out, and held in that position for 10 seconds. The container was then checked for any leakage of coffee, and evaluated using the method described below. 5: No coffee spillage or seepage. 4: Coffee is slightly bleeding. 3: No coffee spillage, but some leaching. 2: There is no leakage of coffee, but it has seeped out to an extent that does not cause any practical problems. 1: Coffee leakage is observed.

[0136] (Smoothness) Ten pulp molded lids were prepared for each of the examples and comparative examples, and were left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. In the above environment, the front and back of the pulp molded lid were touched with hands and evaluated as follows. 5: Very smooth and silky. 4: The surface is slightly fibrous, but smooth. 3: The surface feels smooth, but there is a lot of fiber present. 2: The surface feels smooth, but there is a large amount of fiber present. 1: It is not smooth and feels rough. Below 0:1 level. The numbers in the table are the average of 10 values ​​(rounded to the nearest whole number).

[0137] (Oil resistance) A test solution of 200 mL (equivalent to the mixture of kit number 6 of JAPAN TAPPI No. 41:2000) with a ratio of castor oil / toluene / heptane = 50 / 25 / 25 was prepared and used in the experiment. Five pulp molded lids were prepared for each Example and Comparative Example, and were left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to adjust the temperature and humidity. In the above environment, a drop of the test liquid was dropped from a height of 25 mm on the horizontal part of the back (inner surface) of the pulp molded lid using a dropper of a reagent bottle (a reagent bottle similar to JAPAN TAPPI No. 41:2000), and after 15 seconds, the surface (outer surface) of the pulp molded lid was observed. 4: No liquid penetration was observed on the surface of the lid. 3: A small amount of liquid was seen on the front of the lid, but the area was less than 15% of the area on the back. 2: Liquid penetration was observed on the front of the lid, and the area was more than 15% and less than 50% of the liquid spread on the back. 1: Liquid penetration was observed on the front of the lid, and the area was more than 50% of the liquid spread on the back. The numbers in the table are the average of five (rounded to the nearest whole number).

[0138] (Mouth feel) Five pulp molded lids were prepared from each of the Examples and Comparative Examples, and were provided with openings as shown in the following photographs. They were then left to stand for 24 hours in an environment conforming to ISO 187:1990 (temperature 23±1°C, relative humidity 50±2%) to control the temperature and humidity. The lids were placed over paper cups, and in the above environment, the cups were placed over the mouth through the opening as if drinking water, and the feel of the cup against the mouth was evaluated. 5: There is no feeling of fibers touching your mouth, so it feels completely comfortable. 4: There is a slight feeling of fibers touching your mouth, but it doesn't feel strange. 3: The fibers touch your mouth, but not enough to feel uncomfortable. 2: The fibers touch my mouth and feel a bit strange. 1: The fibers touch my mouth and feel uncomfortable. The numbers in the table are the average of five (rounded to the nearest whole number).

[0139] [Table 2]

[0140] As can be seen from Table 2, the pulp molded lid of the present invention is less likely to deform even when repeatedly engaged and disengaged with a container, and the contents of the container are less likely to leak. [Industrial Applicability]

[0141] The pulp molded lid of the present invention is resistant to deformation even when repeatedly engaged and disengaged with a container, and the contents of the container are less likely to leak, making it ideal as a lid for containers such as paper cups and other beverage containers. [Explanation of symbols]

[0142] 100, 110, 120, 130, 200, 210: pulp molded lid, 10: top, 11: first inclined portion, 12: second inclined portion, 13: third inclined portion, 14: fourth inclined portion, 15: recessed step portion, 15A: first inclined portion, 15B: second inclined portion, 15C: third inclined portion, 17: drinking spout, 17A: drinking spout notch, 19: through hole, 30: outer periphery, 31: lower end (of outer periphery), 33: convex portion, 34: groove portion, 35: flange portion, 37: chamfer part, 41: small lid, 43: hinge part, 45: handle part, 47: hinge part recess, 50 (51, 53, 55, 57, 57): square column part, 51: inclined part, 53: vertical part, 55: rectangular part, 57: trapezoidal part, 61: small lid fitting part, 63: small lid fitting part inclined part, 65: small lid fitting part vertical part, 67: small lid fitting part rectangular part, 69: small lid fitting part trapezoidal part, 1: container, 3: opening end, 5: upper end (of opening end), N: L-shaped jig, H: height of convex part, W: width of convex part

Claims

1. A pulp molded closure having a top and a peripheral edge depending from the peripheral edge of the top, which can be fitted to and unfitted from an open end of a container, the closure having a density of 0.55 g / cm ３ 0.65g / cm or more ３ and the average thickness of the lid is 0.25 mm or more and 1.50 mm or less, and the pulp raw material of the pulp molded lid contains 80 mass % or more of virgin pulp.

2. 2. The pulp molded lid according to claim 1, wherein the pulp raw material of the pulp molded lid contains 100% by mass of virgin pulp.

3. 3. The pulp molded lid according to claim 1, wherein the pulp raw material of the pulp molded lid comprises at least one material selected from the group consisting of softwood kraft pulp, hardwood kraft pulp, bagasse, and bamboo.

4. The pulp-molded lid according to any one of claims 1 to 3, wherein the pulp raw material of the pulp-molded lid is a mixed pulp of one or more kinds of wood pulp selected from softwood kraft pulp and hardwood kraft pulp, and one or more kinds of non-wood pulp selected from bagasse and bamboo.

5. The pulp molded lid according to any one of claims 1 to 4, wherein the blending amount of softwood kraft pulp and bagasse in the pulp raw material of the pulp molded lid is 50 mass % or more.

6. The pulp molded lid according to any one of claims 1 to 5, wherein the Canadian standard freeness of the pulp constituting the pulp molded lid is 100 mL or more and 700 mL or less.

7. The pulp molded lid according to any one of claims 1 to 6, wherein the pulp molded lid has a single layer structure.

8. The pulp molded lid according to any one of claims 1 to 7, wherein the container is a beverage container.

9. The pulp molded lid according to any one of claims 1 to 8, wherein the top portion is provided with at least one of a drinking spout and a notch.

10. The pulp molded lid according to any one of claims 1 to 9, wherein the container is a container for hot beverages and is intended for hot beverages.

11. The pulp molded lid according to any one of claims 1 to 10, wherein the container is a paper cup.

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