JP7435372B2 - Pulp mold lid and its manufacturing method - Google Patents

Description

The present invention relates to a pulp mold lid and a method for manufacturing the same.

Conventionally, container lids are often made of plastic from the viewpoint of cost and the like. For example, Patent Document 1 discloses a plastic molded lid that is attached over a cup-shaped or tray-shaped plastic molded container and sealed by heat-sealing an inner sealing material to a flange on the upper circumference. A plastic molded lid with an inner seal is described, which is characterized in that an inner seal material is laminated on the inner surface of the lid via a peelable layer, and then vacuum and pressure molded.

Japanese Patent Application Publication No. 2007-84075

However, in recent years, ocean pollution caused by plastics has become a problem, and there is a desire to develop products that do not use plastics. Another problem with plastic molded lids is that it is difficult to achieve both ease of closing and ease of opening, and to maintain a fitted state during normal use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a pulp mold lid that is both easy to close and easy to open, and can maintain a fitted state during normal use.

As a result of intensive studies to solve the above problems, the present inventors have provided a pulp mold lid that has the following configuration and is both easy to close and open, and can maintain a fitted state under normal usage conditions. I found out that it can be done. Furthermore, the present inventors have discovered that by setting the surface unevenness within a specific range, it is possible to provide a pulp mold lid with excellent oil resistance and surface smoothness.
That is, the present invention relates to the following <1> to <18>.
<1> A pulp mold lid that includes a top and an outer peripheral edge that hangs down from the outer peripheral edge of the top, and that can be fitted and unfitted to the open end of the container, and that meets the following requirements 1 and 2. Fill at least one with a pulp mold lid.
Requirement 1: Place the pulp mold lid above the open end of the container horizontally to the upper end of the open end, apply a load in the vertical direction at a speed of 100 mm/min, and place the pulp mold lid above the open end of the container. The fitting force, which is the maximum load value when fitted, is 0.2 N/cm or more and 6.0 N/cm or less.
Requirement 2: An L-shaped jig is hooked to the lower end of the outer peripheral edge of the pulp mold lid fitted to the open end of the container and pulled up at a speed of 300 mm/min, and the load is when the fitting is released. The opening force is 0.05 N/cm or more and 1.5 N/cm or less.
<2> The pulp mold lid according to <1>, which satisfies Requirements 1 and 2 above.
<3> The pulp mold lid according to <1> or <2>, wherein the outer peripheral edge portion includes a convex portion that fits into the open end portion.
<4> The pulp mold lid according to any one of <1> to <3>, wherein the top portion includes a recessed step portion.
<5> The pulp mold lid according to any one of <1> to <4>, wherein the outer peripheral edge portion includes a flange portion.
<6> The pulp mold lid according to any one of <1> to <5>, which satisfies at least one of Requirement 3 and Requirement 4 below.
Requirement 3: The height Sp (ISO 25178) of the surface convexity on at least one of the outer surface and inner surface of the pulp mold lid is 80 μm or less.
Requirement 4: The absolute value of the surface unevenness difference Sp+Sv (ISO 25178) on at least one of the outer surface and inner surface of the pulp mold lid is 100 μm or less.
<7> The pulp mold lid according to <6>, which satisfies both the above requirements 3 and 4.
<8> The pulp mold lid according to any one of <1> to <7>, wherein the pulp raw material of the pulp mold lid contains 80% by mass or more of virgin pulp.
<9> The pulp mold lid according to any one of <1> to <8>, wherein the pulp raw material of the pulp mold lid is a mixed pulp of wood pulp and non-wood pulp.
<10> The pulp mold lid according to any one of <1> to <9>, wherein the pulp constituting the pulp mold lid has a Canadian standard freeness of 100 mL or more and 700 mL or less.
<11> The pulp mold lid according to any one of <1> to <10>, wherein the pulp mold lid has a density of 0.45 g/cm ³ or more and 1.0 g/cm ³ or less.
<12> The pulp mold lid according to any one of <1> to <11>, wherein the pulp mold lid has a one-layer structure.
<13> The pulp mold lid according to any one of <1> to <12>, wherein the container is a beverage container.
<14> The pulp mold lid according to any one of <1> to <13>, wherein the top portion includes at least one of a drinking spout and a notch.
<15> The pulp mold lid according to any one of <1> to <14>, wherein the container is a paper cup.
<16> A method for producing a pulp mold lid according to any one of <1> to <15>, which includes a pulp suspension preparation step of preparing a pulp suspension, and a step of preparing a pulp suspension from the pulp suspension through a paper mold. A pulping step of scooping up the pulp, and a second press mold located in the opposite direction to the first press mold while heating the mold intermediate obtained after the pulping step. A method for producing a pulp mold lid, comprising: a press mold; and a hot press step of hot pressing using a press mold.
<17> The method for producing a pulp mold lid according to <16>, wherein the pressure in the hot pressing step is 0.1 MPa or more and 3.0 MPa or less.
<18> The method for producing a pulp mold lid according to <16> or <17>, wherein the temperature in the hot pressing step is 130°C or more and 280°C or less.

According to the present invention, there is provided a pulp mold lid that is both easy to close and easy to open, and can maintain a fitted state under normal use.

FIG. 2 is a schematic vertical cross-sectional view illustrating a pulp mold lid according to the first embodiment. It is a schematic diagram for explaining a state in which a pulp mold lid and a container according to a first embodiment fit together, and a partial view (a) in the figure shows a state in which a pulp mold lid according to a first embodiment is fitted into a container. FIG. 3 is a schematic vertical cross-sectional view illustrating a state in which the pulp mold lid according to the first embodiment is disposed above the container; FIG. It is. It is a schematic diagram for explaining a state in which the fitting between the pulp mold lid and the container according to the first embodiment is released, and the partial view (a) in the figure is the pulp mold lid according to the first embodiment. It is a vertical cross-sectional schematic diagram illustrating a state in which an L-shaped jig is hooked on the lower end of the outer peripheral edge of the container, and a partial view (b) in the figure shows the pulp mold lid and the container according to the first embodiment. FIG. 3 is a schematic vertical cross-sectional view illustrating a state in which the fitting is released. It is an external perspective view illustrating the pulp mold lid according to the second embodiment, and a partial view (a) in the figure is a plan side external perspective view illustrating the pulp mold lid according to the second embodiment, Part (b) in the figure is a bottom side external perspective view illustrating the pulp mold lid according to the second embodiment. It is a side view illustrating a pulp mold lid according to a second embodiment, and a partial view (a) in the figure is a side view illustrating a pulp mold lid according to a second embodiment. Figure (b) is a longitudinal cross-sectional view illustrating the pulp mold lid according to the second embodiment. FIG. 7 is a plan side external perspective view illustrating a pulp mold lid according to a third embodiment. It is a longitudinal cross-sectional view which illustrates the pulp mold lid concerning a modification. It is a longitudinal cross-sectional view which illustrates the pulp mold lid concerning a modification. It is a longitudinal cross-sectional view which illustrates the pulp mold lid concerning a modification. It is a longitudinal cross-sectional view which illustrates the pulp mold lid concerning a modification. It is a longitudinal cross-sectional view which illustrates the pulp mold lid concerning a modification. FIG. 2 is a plan side external perspective view showing an example of the pulp mold lid according to the present example. FIG. 2 is a plan side external perspective view showing an example of the pulp mold lid according to the present example. It is a perspective view of the pulp mold lid produced in the example.

[Pulp mold lid]
The pulp mold lid of the present invention is a pulp mold lid that includes a top and an outer peripheral edge that hangs down from the outer peripheral edge of the top, and that can be fitted and unfitted to the open end of a container, and has the following requirements. 1 and Requirement 2, preferably Requirement 1 and Requirement 2 below.
Requirement 1: Place the pulp mold lid above the open end of the container horizontally to the upper end of the open end, apply a load in the vertical direction at a speed of 100 mm/min, and place the pulp mold lid above the open end of the container. The fitting force (hereinafter also simply referred to as "fitting force" or "fitting shock peak value"), which is the maximum load value when fitted, is 0.2 N/cm or more and 6.0 N/cm or less.
Requirement 2: An L-shaped jig is hooked to the lower end of the outer peripheral edge of the pulp mold lid fitted to the open end of the container and pulled up at a speed of 300 mm/min, and the load is when the fitting is released. The opening force (hereinafter also simply referred to as "opening force" or "opening shock peak value") is 0.05 N/cm or more and 1.5 N/cm or less.

(Mating force)
Specifically, the fitting force of the pulp mold lid is measured as follows. First, the pulp mold lid and the container are left standing for 24 hours in an environment compliant with ISO 187:1990 (temperature 23±1° C., relative humidity 50±2%) to control temperature and humidity. Then, place the pulp mold lid above the open end of the container, horizontally to the top of the open end, and apply a load vertically to the top surface of the pulp mold lid at a speed of 100 mm/min (as shown in Figure 2). (See diagram (a)). Then, the maximum load value (fitting shock peak value) when the pulp mold lid is fitted to the open end of the container is defined as the fitting force (see diagram (b) in FIG. 2). Here, when applying a load in the vertical direction to the upper surface of the pulp mold lid, a plate (for example, a disk-shaped compression jig "PC-5100" manufactured by Imada Co., Ltd.) or the like can be used. Moreover, here, horizontal refers to a generally horizontal state, and for example, a state of about ±5° is allowed.

The fitting force of the pulp mold lid is preferably 0.4 N/cm or more, more preferably 0.0 N/cm or more, from the viewpoint of achieving both ease of closing and opening, and maintaining the fitted state with the container 1 under normal usage conditions. .6 N/cm or more, more preferably 0.8 N/cm or more, even more preferably 1.0 N/cm or more, and preferably 5.5 N/cm or less, more preferably 5.0 N/cm or less, More preferably, it is 4.5 N/cm or less, even more preferably 4.0 N/cm or less.

Unlike plastic lids, when a pulp mold lid is pressed vertically (in the direction of the container) by the user, it fits around the entire circumference of the open end of the container, rather than just a part of the open end of the container. Because they fit together easily, they close tightly and prevent the contents of the container from spilling out.

(Opening force)
Specifically, the opening force of the pulp mold lid is measured as follows. First, a container fitted with a pulp mold lid is left standing for 24 hours in an environment compliant with ISO 187:1990 (temperature 23±1° C., relative humidity 50±2%) to control temperature and humidity. Thereafter, an L-shaped jig is hooked to the lower end of the outer peripheral edge of the pulp mold lid fitted to the open end of the container, and the lid is pulled up at a speed of 300 mm/min (see diagram (a) in FIG. 3). Then, the load value (unsealing shock peak value) when the pulp mold lid and the container are disengaged is defined as the unsealing force (see diagram (b) in FIG. 3). Here, as the L-shaped jig, a chip peeling jig (GT-20) manufactured by Imada Co., Ltd. is used.

The opening force of the pulp mold lid is preferably 0.15 N/cm or more, more preferably 0.15 N/cm or more, from the viewpoint of maintaining the fitting state with the container under normal usage conditions and achieving both ease of closing and ease of opening. It is 25 N/cm or more, and preferably 1.4 N/cm or less, more preferably 1.3 N/cm or less, and still more preferably 1.2 N/cm or less.

(Surface unevenness)
The pulp mold lid of the present invention preferably satisfies at least one of Requirement 3 and Requirement 4 below, and more preferably satisfies both Requirement 3 and Requirement 4 below.
Requirement 3: The height Sp (ISO 25178) of the surface convexity on at least one of the outer surface and inner surface of the pulp mold lid is 80 μm or less.
Requirement 4: The absolute value of the surface unevenness difference Sp+Sv (ISO 25178) on at least one of the outer surface and inner surface of the pulp mold lid is 100 μm or less.
In the present invention, when the pulp mold lid satisfies either of the above requirements 3 and 4, a pulp mold lid with excellent oil resistance and surface smoothness can be obtained.
Although the detailed reason for the above-mentioned effect is unknown, some of the reasons are thought to be as follows. By satisfying at least one of Requirement 3 and Requirement 4, the height of the convexity or the difference in convexity from the average surface of the pulp mold lid surface is reduced, thereby suppressing surface fuzz, etc., and improving surface smoothness. An excellent pulp mold lid is obtained. Further, the pulp mold lid having the above-mentioned surface characteristics also had excellent oil resistance. This means that in order to obtain Sp or Sp+Sv (absolute value) as described above, it is necessary to set the press pressure high when manufacturing the pulp mold lid, and also to apply a specific pulp raw material as the pulp raw material. Since this is preferable, it is considered that a pulp mold lid having excellent oil resistance was obtained as a result.

In the following description, the height Sp of the surface convexity is also simply referred to as Sp, and the depth Sv of the surface concavity is also simply referred to as Sv. Further, the surface unevenness difference Sp+Sv (absolute value) is also simply referred to as Sp+|Sv|.
Here, the height Sp of the surface convexity and the depth Sv of the surface concavity are measured in accordance with ISO 25178.
Sp means the maximum height from the average surface of the surface, and in the present invention, measurement points (10 points, measurement area per point = 10 mm x 10 mm) are randomly selected, and each measurement point is When the Sp obtained in the above is denoted by Sp1, Sp2, Sp3, . . . Sp10, it is determined by the following equation (1).
Height of surface convexity Sp=(Sp1+Sp2+Sp3+...+Sp10)/10 (1)
Similarly, measurement locations (10 locations, measurement area per location = 10 mm x 10 mm) were randomly selected, and the Sv obtained at each measurement location was Sv1, Sv2, Sv3,...Sv10. When, Sv is obtained by the following equation (2).
Depth of surface depression Sv=(Sv1+Sv2+Sv3+...+Sv10)/10 (2)
Here, since Sv is the maximum value of the depth from the average surface, it is generally expressed as a negative value.
Therefore, the surface unevenness difference Sp+Sv (absolute value) is expressed as Sp+|Sv|.
Note that when the area of the measurement target is 1000 mm ² or less, the number of measurement points is reduced and the measurement area at each measurement point is 100 mm ² . Furthermore, if the width is less than 10 mm, the measurement may be performed using a rectangle so that the measurement area is 100 mm ² .

≪Requirement 3≫
Requirement 3 is that the height Sp of the surface convexity on at least one of the outer and inner surfaces of the pulp mold lid is 80 μm or less, as measured in accordance with ISO 25178.
From the viewpoint of surface smoothness, Sp is preferably 75 μm or less, more preferably 65 μm or less, even more preferably 50 μm or less, even more preferably 30 μm or less, even more preferably 20 μm or less, even more preferably 10 μm or less, and even more preferably Preferably it is 5 μm or less. The lower limit is not particularly limited, but from the viewpoint of ease of manufacture, it is preferably 1 μm or more, more preferably 2 μm or more.
Sp is measured according to ISO 25178 by the method described in the Examples.

≪Requirement 4≫
Requirement 4 is a requirement that the surface unevenness difference Sp+Sv (absolute value) of at least one of the outer surface and inner surface of the pulp mold lid is 100 μm or less, as measured in accordance with ISO 25178.
From the viewpoint of surface smoothness, Sp+Sv (absolute value) is 100 μm or less, preferably 95 μm or less, more preferably 90 μm or less, even more preferably 80 μm or less, even more preferably 60 μm or less, even more preferably 40 μm or less, and even more Preferably it is 30 μm or less, even more preferably 20 μm or less, even more preferably 10 μm or less. The lower limit is not particularly limited, but from the viewpoint of ease of manufacture, it is preferably 1 μm or more, more preferably 3 μm or more, and still more preferably 5 μm or more.

In the present invention, the pulp mold lid preferably satisfies at least one of Requirement 3 and Requirement 4, more preferably satisfies at least Requirement 4, and even more preferably satisfies both Requirements 3 and 4. By satisfying both Requirements 3 and 4, a pulp mold lid with better surface smoothness can be obtained.
The outer surface of the pulp mold lid is the surface that comes into contact with a first press mold (female mold), which will be described later, and the inner surface is the surface that comes into contact with a second press mold (male mold), which will be described later. .
In the present invention, it is preferable that Sp is 80 μm or less and Sp+Sv (absolute value) is 100 μm or less on either the outer surface or the inner surface of the pulp mold lid. Among these, since the pulp mold lid of the present invention has excellent tactile sensations such as touch and mouth feel, it is more preferable that the surface that is touched by hands and mouth satisfies the above requirements. Further, it is more preferable that the outer surface and the inner surface satisfy Requirement 3 and Requirement 4.

<Pulp raw material>
Examples of the pulp raw material for the pulp mold lid of the present invention include wood pulp, non-wood pulp, and waste paper, preferably wood pulp and non-wood pulp, and more preferably a mixed pulp of wood pulp and non-wood pulp. Here, the pulp raw material is pulp that constitutes the pulp mold lid.
Examples of wood pulp include wood pulp that is generally used for paper manufacturing, and depending on its preparation method, chemical pulp such as kraft pulp (KP), sulfite pulp (SP), soda pulp (AP); Semi-chemical pulp such as chemical pulp (SCP) and chemical ground wood pulp (CGP); mechanical pulp such as ground wood pulp (GP), thermomechanical pulp (TMP, BCTMP), and refiner ground wood pulp (RGP); etc. Ru.
Examples of wood pulp include softwood pulp and hardwood pulp depending on the raw material. Examples of softwood pulp include pulps obtained from Abies, Pinus, and the like. Further, examples of the hardwood pulp include pulps obtained from the genus Acacia, genus Eucalyptus, genus Asus (for example, poplar), and the like.
Among these, as the wood pulp, softwood kraft pulp (NKP) and hardwood kraft pulp (LKP) are more preferable.

In the present invention, as the hardwood pulp, wood pulps of the genus Acacia and the genus Eucalyptus are preferred from the viewpoint of smoothness of the resulting pulp mold lid. One type of hardwood pulp may be used alone, or two or more types may be used in combination.
In the present invention, as the coniferous pulp, coniferous pulp of the genus Pinus is preferable, and radiata pine is more preferable. By containing coniferous pulp as a pulp raw material, a pulp mold lid with superior strength can be obtained. One type of softwood pulp may be used alone, or two or more types may be used in combination.

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% by mass from the viewpoint of further improving the surface smoothness and oil resistance of the pulp mold lid. The above is more preferably 10% by mass or more, still more preferably 15% 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 It is 90% by mass or less, more preferably 80% by mass or less, even more preferably 55% by mass or less.

Non-wood pulp is fiber obtained from the skin, stems, leaves, and leaf sheaths of plants. Specifically, cotton linters, rags (cotton, linen, hemp, ramie, etc.), straw, esparto, manila hemp such as abaca, xyzal hemp, jute, flax, kenaf, ramie, bamboo, bagasse, ganpi, mitsumata, An example of this is pulp obtained from mulberries.
From the viewpoint of improving the oil resistance of the pulp mold lid, the non-wood pulp preferably contains at least one selected from bagasse and bamboo pulp, and more preferably contains at least one selected from bagasse and bamboo pulp. Preferably, bagasse is more preferable.
When the pulp raw material is a mixed pulp of wood pulp and non-wood pulp, the content of the non-wood pulp in the pulp raw material is preferably 5 mass from the viewpoint of further improving the surface smoothness and oil resistance of the pulp mold lid. % or more, more preferably 10% by mass or more, still 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 It is 85% by mass or less, even more preferably 80% by mass or less, even more preferably 55% by mass or less.

In the present invention, the pulp raw material preferably contains 80% by mass or more of virgin pulp. By setting the content of virgin pulp to 80% by mass or more, a pulp mold lid with better surface smoothness can be obtained. The content of virgin pulp in the pulp raw material is more preferably 85% by mass or more, still more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, even more preferably is 100% by mass.
As the virgin pulp, bleached pulp and semi-bleached pulp are preferred.
Note that unbleached pulp tends to have a large amount of residual lignin, low whiteness, and poor decorative properties. Therefore, the content of unbleached 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 not contained (0% by mass). be.
Moreover, when mercer pulp or crosslinked pulp is contained as a pulp raw material, the strength of the pulp mold lid tends to decrease or the density tends to decrease. Therefore, the content of mercer pulp and crosslinked pulp in the pulp raw material is preferably 20% by mass or less, more preferably 10% by mass or less, still more preferably 5% by mass or less, and even more preferably not contained (0 mass%).
Waste paper pulp tends to have a large amount of residual ink and poor dispersibility. Additionally, the fibers of waste paper tend to become fluffy and deformed. In addition, waste paper pulp has a low degree of whiteness, and there are undeinked fibers that appear long and black while ink remains on the pulp fibers, and black whiskers tend to occur. Dust can also be seen due to gray-looking vinyl and residual black spots. As a result, the appearance and surface smoothness of the resulting pulp mold lid tend to deteriorate, so the content of waste paper pulp in the pulp raw material is preferably 20% by mass or less, more preferably 10% by mass or less. , more preferably 5% by mass or less, even more preferably no content (0% by mass).

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, and even more preferably 200 mL or more, from the viewpoint of pulp raw material productivity and paper-making properties when manufacturing the pulp mold lid. And, from the viewpoint of surface smoothness, preferably 700 mL or less, more preferably 650 mL or less, even more preferably 600 mL or less, even more preferably 520 mL or less, even more preferably 450 mL or less, even more preferably 400 mL or less, Even more preferably, it is 300 mL or less.
The degree of beating may be adjusted so that the Canadian standard freeness is within the above range.
Canadian Standard Freeness is measured in accordance with JIS P 8121-2:2012.

<Other ingredients>
The pulp mold lid is formed using the above-mentioned pulp as a main raw material. The pulp mold lid may be made of 100% pulp, but in addition to pulp, other materials such as various internal additives can be added.
Other ingredients include inorganic substances such as talc and kaolin, inorganic fibers such as glass fiber and carbon fiber, powders or fibers of synthetic resins such as polyolefin, polysaccharides such as carboxymethyl cellulose, sizing agents, wet paper strength agents, and drying agents. Examples include paper strength enhancers, oil resistance agents, retention agents, drainage improvers, bulking agents, sulfuric acid, pH adjusters, pitch control agents, slime control agents, and colorants such as pigments. It is preferable to contain a sizing agent as another component.

Sizing agents include rosin-based sizing agents (for example, acidic rosin-based sizing agents, neutral rosin-based sizing agents), alkyl ketene dimers, alkenyl succinic anhydrides, and styrene-containing polymers such as styrene-(meth)acrylate copolymers. and alkyl ketene dimers are preferred.

Wet paper strength agents for internal addition include polyamide amine-epichlorohydrin resin, epoxidized polyamide polyamine, dialdehyde starch, urea-formaldehyde resin, melamine-formaldehyde, polyacrylamide, methylolated Examples include polyacrylamide and polyethyleneimine.
In addition, water repellents include wax emulsions, metal soaps (alkali salts of sodium, potassium, zinc, lithium, magnesium, etc.), fatty acid chromium complex salts (myristic salt complexes, stearic acid chromic chloride complex salts, etc.), zirconium water repellents, silicone An example is an emulsion.
When the pulp mold lid of the present invention contains non-wood pulp, it is possible to improve oil resistance with just the pulp raw material, so even if the amount of wet paper strength enhancer and water repellent added is reduced. It is possible to obtain sufficient oil resistance with or without addition. Note that this does not exclude the addition of a wet paper strength agent or water repellent for the purpose of obtaining higher oil resistance and water resistance.

The pulp mold lid of the present invention may have a multi-layer structure by performing the papermaking process described below multiple times or by hot-pressing a plurality of mold intermediates in the hot-pressing process, but the surface smoothness and From the viewpoint of superior oil resistance, it is preferable to have a one-layer structure.

(density)
From the viewpoint of further improving surface smoothness and oil resistance, the density of the pulp mold lid of the present invention is preferably 0.45 g/cm ³ or more, more preferably 0.50 g/cm ³ or more, and even more preferably 0. .60 g/cm ³ or more, and preferably 1.0 g/cm ³ or less, more preferably 0.95 g/cm ³ or less.
The density of the pulp mold lid can be measured according to JIS P 8118:2014. Note that JIS P 8118:2014 is a method used for paper and paperboard, and in the present invention, there may be cases where the sample size cannot be taken as specified, and in that case, the sample size may be adjusted appropriately and used for measurement. . The basis weight is measured according to JIS P 8124:2011, and the sample size is adjusted as described above. The flat part of the lid is used for measurement.

(Basic weight)
The basis weight of the pulp mold lid is preferably 200 g/m ² or more, more preferably 250 g/m ² or more, even more preferably 300 g/m ² or more from the viewpoint of water resistance and strength, and from an economic viewpoint. is preferably 1500 g/m ² or less, more preferably 1000 g/m ² or less, even more preferably 500 g/m ² or less.
The basis weight of the pulp mold lid is measured by the method described in Examples.

(thickness)
The thickness of the pulp mold lid is preferably 0.30 mm or more, more preferably 0.35 mm or more, and preferably 1.50 mm or less, more preferably 1.20 mm or less, from the viewpoint of heat retention and handling properties. It is. The thickness of the pulp mold lid is measured by the method described in the Examples.

Note that the container is not particularly limited as long as it can accommodate the contents, but is preferably a food container or a beverage container, and more preferably a beverage container. Beverage containers are made of, for example, plastic (e.g., thermoplastic resins such as PET (e.g., C-PET), PP, PE, and PS; biodegradable plastics; plastics mixed with natural materials), styrofoam, paper (e.g., high-quality Examples include cups made of paper (paper, pulp mold), and paper cups are more preferred. In addition, it is preferable that the container has an open end curled outward.

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

(Direct printing method)
The direct printing method applies ink or resin directly to the surface of the pulp mold lid for the purpose of adding color, pattern, pattern, etc., waterproofness, moisture resistance, etc. Through impregnation, printing, etc. One example is a method of surface-processing a pulp mold lid.
For printing, any printing means such as letterpress printing using a rubber plate or resin plate, silk screen printing, pad printing, electrostatic printing, thermal transfer printing, etc. may be used. By printing, designs, characters, etc. can be provided on the surface of the obtained pulp mold lid.
Alternatively, it may be printed directly onto the pulp mold lid by brushing, spraying, or the like. Among these, spray coating is preferred from the viewpoint of uniformly applying the resin and the like. Spray application may be performed by air spray, airless spray, electrostatic spray, or the like.
When providing waterproof or moisture-proof properties to the surface of the pulp mold lid, acrylic resin, styrene resin, urethane resin, melamine resin, olefin resin, epoxy resin, polyvinyl alcohol resin, vinylidene chloride resin A water-based emulsion paint containing resins such as these in solid content, an aqueous solution paint of these resins, or an organic solvent-based paint may be applied.

(Lamination method)
The lamination process 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, ethylene-vinyl alcohol copolymers, thermoplastic resin films such as polyacrylonitrile, modified polyethylene terephthalate, aliphatic polyesters, etc. Examples include degradable resin films. In consideration of manufacturing cost, moldability, etc., polyolefin resins are preferred, and in terms of environmentally friendly disposal, biodegradable resin films are preferred. The lamination process may be performed by laminating two or more of these resin films.
Although the thickness of the resin film is not particularly limited, it is preferably 10 μm or more and 300 μm or less.

By laminating the above-described resin film, functions such as water resistance, oil resistance, and gas barrier properties can be improved or imparted.
In addition, a pattern may be printed in advance on the resin film to be laminated, or colored pigments, fine particles (pearl pigments, holograms, etc.), luminous dyes, luminous pigments, etc. may be added. By using such a resin film, gloss and design can be imparted to the surface of the pulp mold lid.

The lamination process may be performed on the pulp mold lid by a known method such as extrusion lamination, heat lamination, dry lamination, or wet lamination.
Among these, thermal lamination is preferred, vacuum lamination and vacuum press are preferred, and vacuum lamination is more preferred.
Vacuum lamination may be performed by deforming the sheet placed on top of the substrate by suction from the base material side (pulp mold side), or by dividing the upper and lower chambers, which have been evacuated in advance, into two with a resin film. Alternatively, the upper chamber equipped with a resin film heating device may be pressurized, and the resin film may be laminated onto a base material (pulp mold lid) placed in the lower chamber.
In addition, a vacuum press deforms silicone rubber, etc. into the shape of the base material by vacuum suction from the base material (pulp mold lid) side, and in some cases, applies pneumatic force from the top, and then presses the material between the silicone rubber, etc. and the base material. The resin film is laminated to the base material by the pressure of silicone rubber.
Alternatively, the resin film may be preformed using a mold to match the shape of the pulp mold lid, and then laminated with the pulp mold lid.

The lamination process may be performed by a conventionally known method, and examples of the vacuum lamination device include a TOM molding machine (manufactured by Fuse Vacuum Co., Ltd.).
In addition, conditions such as temperature and pressure during lamination may be appropriately selected depending on the material and thickness of the resin film to be laminated, the shape of the base material, the presence or absence of adhesive, etc. For example, the heating temperature of the heater is 80 ° C. The lamination is carried out at a temperature above 200°C or below.

During lamination, an adhesive may or may not be applied between the resin film and the pulp mold lid. As the adhesive, polyurethane adhesive, polyacrylic adhesive, polyester adhesive, epoxy adhesive, polyvinyl acetate adhesive, cellulose adhesive, and other laminating adhesives can be used. . When applying an adhesive, a coloring pigment, a pearl pigment, fine particles (such as a hologram), a luminous pigment, a luminous dye, etc. may be added to the adhesive.

(Transfer method)
Examples of the transfer method include various transfer methods such as a hot stamp transfer method, an in-mold transfer method, and a water pressure transfer method, and either a dry transfer method or a wet transfer method may be used. Further, in the in-mold transfer method, a preforming step may be added.
Among the transfer methods, a hot stamp transfer method (hereinafter also simply referred to as a "hot stamp method") is preferred. The hot stamping method uses a film called "foil" on which metal is vapor-deposited or pigment is coated, and the film is thermally transferred to a base material via a thermal adhesive layer provided on the surface of the foil. The foil used in the hot stamping method is laminated in the following order: a base film with release properties (for example, biaxially stretched polyester film), a release layer (protective layer), a pattern layer or vapor deposition layer, and a thermal adhesive layer. If necessary, a release layer is provided between the base film and the protective layer. Hot stamping methods include (i) up-down method and (ii) roll transfer method, and the principle is that the pattern layer or vapor deposition layer in the area where heat and pressure is applied is transferred to the base material (pulp mold lid). It's the same. In the up-down method, a template with a built-in heater is pressed against the base material from the base film side, and the pattern layer or vapor deposition layer is transferred to the base material via the thermal adhesive layer. Similarly, in the roll transfer method, a heated roller is pressed from the base film side to transfer the pattern layer or vapor deposition layer onto the base material. Furthermore, by subjecting the base film to grinding, gloss treatment, unevenness, etc., it is also possible to shape (impart unevenness) on the pattern layer and vapor deposited layer during transfer.

(vapor deposition)
Vapor deposition may be performed by a conventionally known vapor deposition method, and may be either physical vapor deposition or chemical vapor deposition. Although not particularly limited, vapor deposition is preferably performed for the purpose of imparting metallic luster to the pulp mold lid, and vacuum vapor deposition, which is physical vapor deposition, is preferred. is more preferable.
As the deposition material, it is preferable to use metals such as aluminum, chromium, zinc, gold, silver, platinum, and nickel, and oxides and fluorides such as SiO ₂ , TiO ₂ , ZrO ₂ , and MgF ₂ .
The thickness of the vapor deposited layer is not particularly limited, but is preferably 0.1 μm or more.

[Manufacturing method of pulp mold lid]
Although the method for manufacturing the pulp mold lid is not particularly limited, it is preferable to manufacture the pulp mold lid by a manufacturing method having the following steps 1 to 3 in this order.
Step 1: A pulp suspension preparation step for preparing a pulp suspension. Step 2: A papermaking step in which pulp is made from the pulp suspension through a papermaking mold. Step 3: The pulp obtained after the above papermaking step. A hot press step in which a mold intermediate is heated and hot-pressed by a first press mold and a second press mold located in the opposite direction to the first press mold. In step 1, pulp raw material, size A pulp suspension (pulp slurry) is prepared by adding other additives such as a pulp agent. The concentration of the suspension (slurry concentration) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.0% by mass, from the viewpoint of surface smoothness, dimensional stability, and productivity. .5% by mass or more, and preferably 7% by mass or less, more preferably 5% by mass or less, even more preferably 3% by mass or less.

Step 2 is a papermaking process in which pulp is produced from the pulp suspension through a papermaking die.
A forming mold such as a wire mesh mold with a vacuum-drawn water-permeable structure is immersed in the pulp suspension, and the pulp suspension is sucked into the forming mold and the water is discharged. At the same time, the pulp fibers are laminated and adsorbed onto the mold. A three-dimensional wet paper paper symmetrical to the mold is formed, and then the mold is lifted out of the pulp suspension, and the water-containing three-dimensional wet paper paper is dehydrated by suction or pressure.
At this time, while continuing vacuum suction, the mold with the pulp layered and adsorbed on the mold surface is approached with a mold (releasing device) applied with vacuum suction, facing the pulp suction surface. After the intermediate is dehydrated by compressed vacuum suction, the vacuum pressure of the molding die is returned to normal pressure, and the mold is pulled back and released with the pulp mold intermediate adsorbed to the mold.

Step 3 is to heat the mold intermediate obtained after the papermaking step using a first press mold and a second press mold located in the opposite direction to the first press mold. This is a hot pressing process.
In step 3, the dehydrated pulp mold intermediate obtained in step 2 is transferred to, for example, a first press mold for hot pressing consisting of a porous mold. The pulp mold intermediate transferred to the first press mold is located in a direction opposite to the first press mold and is engaged with the first press mold. A predetermined pulp mold lid is obtained by heating and pressurizing with a second press mold for hot press.
Note that at least one of the first press mold and the second press mold for hot press has an electric heater built therein, so that at least one of the first press mold and the second press mold Preferably one is heated. Alternatively, the entire mold including the first press mold and the second press mold may be housed in a furnace into which hot air is introduced, so that the hot air can also pass through the inside of the mold.

In step 3 (hot press step), the pressure during pressing by the first press mold and the second press mold is preferably 0.1 MPa or more, more preferably 0.1 MPa or more, from the viewpoint of obtaining a pulp mold lid with excellent surface smoothness. Preferably 0.3 MPa or more, more preferably 0.4 MPa or more, even more preferably 0.6 MPa or more, and from the viewpoint of power consumption and device load, preferably 3.0 MPa or less, more preferably 2.0 MPa It is more preferably 1.5 MPa or less.

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 mold lid with excellent surface smoothness. From the viewpoint of power consumption, device load, and suppression of discoloration, the temperature is preferably 280°C or lower, more preferably 250°C or lower, and even more preferably 230°C or lower.

The pulp mold lid obtained as described above may be further processed such as cutting off unnecessary parts and drilling holes as necessary to form, for example, at least one of a drinking spout and a notch.

Hereinafter, preferred embodiments for carrying out the present invention will be described using the drawings. Note that the following embodiments do not limit the inventions claimed in each claim, and not all combinations of features described in the embodiments are essential to the solution of the invention. .

First, a pulp mold lid 100 according to a first embodiment will be described using FIGS. 1 to 3.

[Pulp mold lid according to first embodiment]
As shown in FIGS. 1 to 3, the pulp mold lid 100 according to the first embodiment includes 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 includes an open end of the container 1. The pulp mold lid 100 is capable of being fitted into and unfitted from the portion 3, and satisfies at least one of the following requirements 1 and 2, and preferably satisfies the following requirements 1 and 2.
Requirement 1: The pulp mold lid 100 is placed above the open end 3 of the container 1 horizontally with respect to the upper end 5 of the open end 3, and a load is applied in the vertical direction at a speed of 100 mm/min. The fitting force, which is the maximum load value when fitting into the open end 3 of , is 0.2 N/cm or more and 6.0 N/cm or less.
Requirement 2: Hook the L-shaped jig N to the lower end 31 of the outer peripheral edge 30 of the pulp mold lid 100 fitted to the open end 3 of the container 1, and pull it up at a speed of 300 mm/min until the fitting is released. The opening force, which is the load value when the package is opened, is 0.05 N/cm or more and 1.5 N/cm or less.

The top portion 10 is the longest portion of the outer peripheral edge 30 of the pulp mold lid 100 from the lower end 31, that is, the highest portion of the pulp mold lid 100, and is a portion that covers the opening of the container 1. The top portion 10 may be provided with a step or the like depending on the use of the container 1 and the like. An uneven pattern can be formed on the top portion 10 using a mold used for molding, a laser, or the like. Further, when the container 1 that fits into the pulp mold lid 100 is a beverage container, the top portion 10 preferably includes at least one of a drinking spout and a notch (not shown). A straw or the like can be inserted into the cut.

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 mold lid 100. The inner peripheral side of the outer peripheral edge portion 30 is provided with a convex portion 33 that fits into the open end portion 3 of the container 1 . The outer peripheral edge portion 30 may be provided with a step, a flange, etc. depending on the use of the container 1 and the like. An uneven pattern can also be formed on the outer peripheral edge portion 30 using a mold used for molding, a laser, or the like. Further, the outer circumferential edge portion 30 may have a convex portion on the outer circumferential side, a concave portion, or a convex portion and a concave portion.

The convex portion 33 only needs to protrude from the outer peripheral edge portion 30 toward the inside of the pulp mold lid 100 so as to be able to fit into the open end portion 3 of the container 1 . The convex portion 33 may be solid or may be hollow in a vertical cross-sectional view, and is formed by recessing the outer circumferential edge portion 30 from the outer circumferential side and protruding the inner circumferential side of the groove portion. It may be. The convex portion 33 may be formed in one line over one circumference of the inner circumference of the outer peripheral edge portion 30 and may be continuous, or may be formed in two or more lines. Further, a plurality of convex portions 33 may be formed on the inner circumference side of the outer circumferential edge portion 30 and may be arranged discontinuously in a broken line shape, or may be formed only on a part of the inner circumference of the outer circumferential edge portion 30. For example, it may be arranged at half the inner circumferential diameter of the outer circumferential edge portion 30. By adjusting the height H and width W of the convex portion 33 according to the shape of the opening end 3, etc., the fitting force and unsealing force of the pulp mold lid 100 are adjusted (see FIG. 1).

The pulp mold lid 100 placed above the container 1 is pressed in the vertical direction (in the direction of the arrow in FIG. 2 (a)), so that the open end 3 of the container 1 The open end 3 of the container 1 and the protrusion 33 of the pulp mold lid 100 can be fitted over the protrusion 33 of the pulp mold lid 100 (see diagram (b) in FIG. 2).

Further, the pulp mold lid 100 fitted to the container 1 can be opened by hooking a finger or the like on the lower end 31 of the outer peripheral edge 30 and pulling it up (see part (a) in FIG. 3). However, it crosses over the open end 3 of the container 1, and the fitting with the container 1 is released (see part (b) in FIG. 3).

The pulp mold lid 100 according to the first embodiment has been described above. Next, a pulp mold lid 110 according to a second embodiment will be described using FIGS. 4 and 5. Configurations that are the same or similar to those of the embodiment described above may be given the same reference numerals and descriptions thereof may be omitted.

[Pulp mold lid according to second embodiment]
As shown in FIGS. 4 and 5, the pulp mold lid 110 according to the second embodiment includes a top portion 10 and an outer peripheral edge portion 30 hanging down from the outer peripheral edge of the top portion 10, and is attached to a container (not shown). It can be fitted into and unfitted from the open end, and satisfies at least one of Requirement 1 and Requirement 2 above, preferably Requirement 1 and Requirement 2 above.

The top portion 10 of the pulp mold lid 110 according to the second embodiment includes inclined portions 11 and 12 and a recessed step portion 15 having a recessed step.

The inclined parts 11 and 12 are arranged to form a recessed step part 15. The inclined parts 11 and 12 according to the second embodiment include a first inclined part 11 and a second inclined part 12. Although the first slope part 11 and the second slope part 12 have different slopes, the slopes may be the same, or the slopes may change midway. Further, the inclined parts 11 and 12 may have only the first inclined part 11 and not the second inclined part 12, and the number of inclined parts 11 and 12 can be changed as appropriate. The first inclined portion 11 or the second inclined portion 12 may be perpendicular to the recessed step portion 15. Moreover, the first inclined part 11 and the second inclined part 12 may have a curved part.

The recessed step portion 15 according to the second embodiment is preferably recessed to a depth such that a convex portion 33 on the inner peripheral side of the outer peripheral edge portion 30 described later is arranged to face the inclined portions 11 and 12. With such a configuration, the pulp mold lid 110 is fitted so that the open end of the container (not shown) is guided and supported by the inclined parts 11 and 12 and is fitted over the convex part 33, and the fitting is completed. However, since the inclined portions 11 and 12 support the open end of the container (not shown), the fitted state with the container becomes stronger. In addition, in this embodiment, although it is comprised with one recessed step part 15, it may be provided with several recessed step parts. When a plurality of recessed step portions are provided, a plurality of inclined portions are formed to form the recessed step portions.

The outer peripheral edge part 30 of the pulp mold lid 110 according to the second embodiment includes a convex part 33 that fits into an open end of a container (not shown), a groove part 34 that is recessed from the outer peripheral side, and an outer peripheral edge part 30 that is recessed from the outer peripheral side. It is configured to include a flange-like flange portion 35 extending outward from the lower end 31 of the portion 30 and a chamfered portion 37 .

In this embodiment, the convex portion 33 is formed on the inner peripheral surface side of the groove portion 34 . That is, the convex portion 33 is formed by protruding the inner circumferential side of the groove portion 34 which is formed by recessing the outer circumferential edge portion 30 from the outer circumferential side. This convex portion 33 fits into an open end of a container (not shown). In this embodiment, the outer peripheral edge part 30 has a plurality of groove parts 34 (convex parts 33), and the groove parts 34 (convex parts 33) are arranged discontinuously at equal intervals from the upper end or the lower end of the outer peripheral edge part 30. They are arranged so that the distance is constant. Further, in this embodiment, the groove portion 34 (convex portion 33) has a rectangular shape. However, the shape and arrangement position of the groove portion 34 and the convex portion 33 are not limited thereto.

By providing the flange portion 35, when the user of the pulp mold lid 110 releases the fitted state between the pulp mold lid 110 and a container (not shown), the user's fingers are easily caught on the flange portion 35, It becomes easier to open the pulp mold lid 110.

When the chamfered portion 37 is formed on the pulp mold lid 110, there is no edge angle, so the pulp mold lid 110 has an overall rounded impression, and has the effect of being excellent in design.

The pulp mold lid 110 according to the second embodiment is also pressed from above in the vertical direction (see the arrow in FIG. The portion is able to ride over the convex portion 33 of the pulp mold lid 110, engage with the convex portion 33 of the pulp mold lid 110, and fit into a container (not shown).

In addition, the pulp mold lid 110 fitted to the container (not shown) can be raised to a convex shape by the user hooking a finger or the like on the lower end 31 of the outer peripheral edge 30 and pulling it up (see part (a) in FIG. 3). The portion 33 passes over the open end of the container, and the fitting with the container is released (see part (b) in FIG. 3).

The pulp mold lid 110 according to the second embodiment has been described above. Next, a pulp mold lid 120 according to a third embodiment will be described using FIG. 6. Configurations that are the same or similar to those of the embodiment described above may be given the same reference numerals and descriptions thereof may be omitted.

[Pulp mold lid according to third embodiment]
As shown in FIG. 6, the pulp mold lid 120 according to the third embodiment includes 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 includes an open end of the container (not shown). can be fitted and unfitted, and satisfies at least one of Requirements 1 and 2 above, and preferably satisfies Requirements 1 and 2 above.

The top part 10 according to the third embodiment includes a first slope part 11, a first recessed step part 15A, a second slope part 12, a second recessed step part 15B, a drinking spout 17, and two through holes. 19, 19, a third inclined part 13, a third recessed step part 15C, and a fourth inclined part 14.

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 slope part 11, the second slope part 12, the third slope part 13, and the fourth slope part 14 are respectively the first recessed step part 15A, the second recessed step part 15B, the third recessed step part 15C, and It may be perpendicular to the third recessed step portion 15C. Further, the first slope portion 11, the second slope portion 12, the third slope portion 13, and the fourth slope portion 14 may not have constant slopes, and may have curved portions having a curved shape.

In this embodiment, the drinking spout 17 has a substantially rectangular shape and is arranged at the top portion 10 (the highest portion of the pulp mold lid 120), but this can be changed as appropriate. The two through holes 19, 19 are passages for steam and air, and are installed so that the user can smoothly drink the beverage from the spout 17. Although the through hole 19 is not particularly limited, it is preferable that the through hole 19 be arranged at a position away from the drinking spout 17. The number of through holes 19 may be one or more, and the number and installation position thereof can be changed as appropriate. In this embodiment, the two through holes 19, 19 are respectively arranged at the top portion 10 (the highest portion of the pulp mold lid 120) and the second recessed step portion 15B.

In this embodiment, the first recessed step portion 15A and the second recessed step portion 15B have a substantially semicircular shape when viewed from the direction of use when a user drinks a beverage from the spout 17, The chipped portion of the recessed step portion 15A is arranged on the lower chord, and the chipped portion of the second recessed step portion 15B is arranged on the upper chord, but this can be changed as appropriate. Further, in the present embodiment, the third recessed step portion 15C is configured to extend outward from the lower end of the third inclined portion 13 in a brim shape, but this can be changed as appropriate.

The top portion 10 according to the third embodiment includes a cylindrical portion including the third inclined portion 13, a third flange-like recessed step portion 15C, and a fourth inclined portion 14.

The outer peripheral edge part 30 according to the third embodiment includes a groove part 34 that is recessed from the outer peripheral side, a convex part (not shown) that projects on the inner peripheral side of the groove part 34, and a convex part (not shown) that extends from the lower end 31 of the outer peripheral edge part 30. It is configured to include a brim-shaped flange portion 35 extending outward and a chamfered portion 37.

The pulp mold lid 120 according to the third embodiment also closes the open end of the container (not shown) by applying a load to the top surface of the pulp mold lid 120 in the vertical direction (see the arrow in the diagram (a) in FIG. 2). The opening end of the container (not shown) and the protrusion 33 of the pulp mold lid 120 can fit together by passing over the protrusion 33 of the pulp mold lid 120.

Although the preferred embodiments of the present invention have been described above, the technical scope of the present invention is not limited to the range described in the above embodiments. Various changes or improvements can be made to the above embodiments.

For example, in the above-described embodiments, the case where the pulp mold lids 110 and 120 can be fitted and unfitted with a container having a circular shape in a plan view has been exemplified and explained, It may be possible to fit and unfit the container. That is, the top of the pulp mold lid may have a rectangular shape in plan view.

Further, for example, in the above-described embodiment, when the convex portion 33 is formed in one line around the inner circumference of the outer circumferential edge portion 30, and when the convex portion 33 has a rectangular shape and is discontinuously disposed at equal intervals, The case where the distance from the upper end or the lower end is constant has been exemplified and explained. 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 lower end of the outer peripheral edge portion 30 is not constant, or may be a discontinuous curved line. 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, an inverted U shape, etc. or a combination thereof. That is, when the outer peripheral edge portion 30 has a plurality of convex portions 33, the convex portions 33 may have the same shape or a combination of different shapes. Further, when the outer peripheral edge portion 30 includes a plurality of convex portions 33, the intervals between the convex portions may not be equal.

Further, for example, in the above-described embodiment, the case where the convex portion 33 has a substantially semicircular shape in longitudinal cross section has been exemplified, but the shape of the convex portion 33 is not limited to this. As illustrated in FIG. 7A, the convex portion may have a triangular shape or a polygonal shape such as a quadrangular shape in a vertical cross-sectional view. Moreover, as illustrated in the partial view (b) in FIG. 7, the convex portion may have a hook shape in a longitudinal cross-sectional view. Further, as illustrated in FIG. 7 (c), the convex portion may have undulations, that is, unevenness.

Further, for example, in the above-described embodiment, the case where the convex portions 33 are arranged in one row has been described as an example, but the arrangement of the convex portions 33 is not limited to this. As illustrated in FIG. 8, the convex portions may be arranged in two rows, or may be arranged in three or more rows, and the number and arrangement position thereof can be changed as appropriate. In FIG. 8, in a vertical cross-sectional view of the pulp mold lid, two protrusions are arranged so as to have a certain distance from the upper end or the lower end of the outer peripheral edge. , may be arranged at different distances from the upper end or the lower end of the outer peripheral edge. Furthermore, the two or more convex portions arranged on the outer peripheral edge may be discontinuous, and the shape thereof is not particularly limited, and can be appropriately changed to the above-mentioned shape or the like. Furthermore, two or more convex portions arranged on the outer peripheral edge may be curved or discontinuous curved. Moreover, as illustrated in FIG. 8, the pulp mold lid of the present invention may or may not be provided with the above-mentioned groove portion 34.
Note that when there are two or more fitting shock peak values, the maximum load value (fitting shock peak value) is taken as the fitting force.

Furthermore, for example, in the above-described embodiment, the case where the outer peripheral edge part 30 has the convex part 33 has been explained, but as illustrated in FIG. 9, the outer peripheral edge part 30 has the convex part 33. You don't have to.

Further, for example, the pulp mold lid 100 according to the first embodiment has been described with an example in which the top portion 10 is flat, but as illustrated in FIG. does not need to be flat, and may be configured in a dome shape that rises toward the center of the pulp mold lid. Further, the top portion may be configured to become lower toward the center of the pulp mold lid. That is, the top portion may have a height difference.

Further, as illustrated in FIG. 10, the top portion may have a sloped portion and a recessed step portion like the pulp mold lid 110 according to the second embodiment. As illustrated in the partial view (a) in FIG. 10, the top portion may have one inclined portion and one recessed step portion, or as illustrated in the partial view (b) in FIG. As illustrated in Figure (c), a plurality of inclined parts and recessed step parts may be provided, and the number and arrangement position thereof can be changed as appropriate. Further, the recessed step portion opposing portion opposite to the recessed step portion on the top may be configured to have a linear shape, as illustrated in the partial view (b) in FIG. As illustrated in Figure (c), it may have a shape corresponding to the shape of the opposing recessed step portion, and the shape can be changed as appropriate.

Further, for example, in the above-described embodiment, the case where the thickness of the outer peripheral edge portion 30 is constant has been described, but as illustrated in FIG. 11, the thickness of the outer peripheral edge portion 30 is not constant. Good too. As illustrated in the partial view (a) in FIG. 11, it may be widened toward the lower end of the outer peripheral edge portion 30, or as illustrated in the partial view (b) in FIG. The thickness may decrease from the top to the bottom of the peripheral edge portion 30. That is, the thickness of the outer peripheral edge portion 30 does not need to be constant and may have a difference.
Note that the thickness of the outer peripheral edge portion 30 refers to the thickness of the portion excluding the flange portion 35 when the outer peripheral edge portion 30 is included.

The pulp mold lid according to the above-mentioned modification may have the configuration of the pulp mold lid 100, 110, 120 according to the embodiment described above, or the pulp mold lid according to another modification.

Specifically, the pulp mold lid according to the above-mentioned modification may have, for example, the flange portion 35, the drinking spout 17, or the through hole 19. It may also have a notch.
For example, the outer peripheral edge of the pulp mold lid illustrated in FIGS. 7 to 9 may be directed toward the lower end of the outer peripheral edge, as in the pulp mold lid illustrated in FIG. , it may be widened at the end, or the thickness may become smaller from the top to the bottom of the outer circumferential edge, as illustrated in FIG. 11 (b).
Further, for example, the pulp mold lid illustrated in FIGS. 7 to 9 and 11 may have an inclined portion and a recessed stepped portion, and the number and arrangement position thereof can be changed as appropriate.
Further, for example, although FIGS. 9 to 11 illustrate a case in which the outer peripheral edge of the pulp mold lid does not have a convex portion, the outer peripheral edge of the pulp mold lid is not limited to this, and may have a convex portion. . In that case, the shape of the pulp mold lid 100 according to the first embodiment and the shape of the pulp mold lid according to the modification may be the same, but the shape, number, and arrangement position of the convex portions are not particularly limited. The convex portions may have the above-mentioned shape, may be discontinuous, and may be arranged at different distances from the upper end or lower end of the outer peripheral edge.
Furthermore, for example, two or more convex portions of the pulp mold lid illustrated in FIG. 7 may be arranged, or two or more convex portions may be arranged discontinuously.

It is clear from the claims that such modifications or improvements may be included within the technical scope of the present invention.

EXAMPLES The features of the present invention will be explained in more detail below with reference to Examples and Comparative Examples. The materials, usage amounts, proportions, processing details, processing procedures, etc. shown in the following examples can be changed as appropriate 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.

[Preparation of pulp mold lid]
Example 1-1
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 620 mL), which is a bleached hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer) is added as a sizing agent in terms of solid content to 100% by mass of the pulp slurry. , manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 7% by mass. In order to remove aggregates, the slurry is filtered, a paper mold with a metal mesh attached to the surface is submerged in the filtered slurry, vacuum is applied from inside the mold, and the pulp slurry is sucked onto the mesh. Then, a three-dimensional wet paper was formed. The wet paper is transferred to a dehydration mold, dehydrated under pressure of 0.65 MPa, then transferred to a mold heated to 180° C., and further dried under pressure of 1.1 MPa. After cutting off the excess portion, a pulp mold lid 200 shown in FIG. 12 was obtained by punching.
As shown in FIG. 12, the pulp mold lid 200 includes a top portion 10 and an outer peripheral edge portion 30 that hangs down from the outer peripheral edge of the top portion 10. Further, the outer peripheral edge 30 includes a single groove 34 which is recessed from the outer peripheral side and is arranged around the inner circumference; It includes a single convex portion (not shown) that fits with the end portion, a flange portion 35 extending outward from the lower end 31 of the outer peripheral edge portion 30, and a chamfered portion 37.
The basis weight of the pulp mold lid 200 was 400 g/m ² . The inner diameter of the pulp mold lid 200 was 80 mm, which is approximately the same as the outer diameter of the container (paper cup) used for measuring the fitting force and opening force. The size (outer diameter) of the pulp mold lid was approximately 82 mm, the thickness was approximately 0.7 mm, and the density was approximately 0.57 g/cm ³ . The depth and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) when the pulp mold lid 200 was fitted into the container (paper cup) was 0.30 N/cm. The pulp mold lid 200 had an opening force (opening shock peak value) of 0.10 N/cm when the fitting was released.

Example 1-2
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-3
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-4
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-5
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-6
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-7
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-8
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-9
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Example 1-10
The basis weight of the pulp mold lid was changed to 550 g/m ² and the density to 0.55 g/cm ³ , and the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 0. A pulp molded lid was obtained in the same manner as in Example 1-1, except that the depth and width of the convex portion were adjusted to .18 N/cm. The pulp mold lid had an opening force (opening shock peak value) of 0.12 N/cm.

Example 1-11
The basis weight of the pulp mold lid was changed to 300 g/m ² and the density was changed to 0.58 g/cm ³ , and the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 6. A pulp mold lid was obtained in the same manner as in Example 1-1, except that the depth and width of the convex portion were adjusted so that the pressure was .2N/cm. The opening force (opening shock peak value) of the pulp mold lid was 1.40 N/cm.

Example 1-12
The mold was changed, and as shown in Figure 4, the shape of the convex part was changed to partially form grooves (convex parts) and arrange the convex parts in a broken line shape, instead of a single line. A pulp molded lid was obtained in the same manner as in Example 1-1, except that the depth and width of the part were adjusted and the fitting force (fitting shock peak value) was adjusted to 1.0 N/cm. The pulp mold lid had an opening force (opening shock peak value) of 0.24 N/cm.

Example 1-13
The mold was changed to obtain a pulp mold lid 210 as shown in FIG. 13.
As shown in FIG. 13, the pulp mold lid 210 includes a top portion 10 and an outer peripheral edge portion 30 hanging down from the outer peripheral edge of the top portion 10, and the top portion 10 includes an inclined portion 11 and a first recessed step portion 15A. The outer circumferential edge portion 30 further includes a flange portion 35 and a chamfered portion 37. In the pulp mold lid 210 according to Example 1-13, the second recessed step portion 15B is shorter in distance from the top of the top portion 10 than the first recessed step portion 15A. Note that the vertical cross section of the pulp mold lid 210 has a shape in which a flange portion 35 is formed on the pulp mold lid illustrated in the partial view (b) of FIG.
The basis weight of the pulp mold lid 210 was 200 g/m ² . The inner diameter of the pulp mold lid 210 was 80 mm, which was approximately the same as the outer diameter of the container (paper cup) used for measuring the fitting force and opening force. The size (outer diameter) of the pulp mold lid was approximately 82 mm, the thickness was approximately 0.3 mm, and the density was approximately 0.58 g/cm ³ .
The opening force (opening shock peak value) when the pulp mold lid 210 was released from the fitting was 0.15 N/cm. Furthermore, the pulp mold 210 lid of Example 1-13 had a fitting shock peak value of 0.60 N/cm when fitting into the container.

Comparative example 1-1
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Comparative example 1-2
The procedure was the same as in Example 1-1, except that the height and width of the convex portion were adjusted so that the fitting force (fitting shock peak value) and unsealing force (unsealing shock peak value) became the values listed in Table 1. A pulp molded lid was obtained.

Reference example 1-1
In place of the pulp mold lid 200, a commercially available plastic lid (trade name "SMT-280-F" manufactured by Tokan Kogyo Co., Ltd.) was used.

Example 2-1
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL), which is a hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer, (manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 0.7% by mass. In order to remove aggregates, the slurry is filtered, a paper mold with a metal mesh attached to the surface is submerged in the filtered slurry, vacuum is applied from inside the mold, and the pulp slurry is sucked onto the mesh. Then, a three-dimensional wet paper was formed. The wet paper was transferred to a dehydration mold, dehydrated under pressure of 0.7 MPa, then transferred to a mold heated to 180°C, and further dried under pressure of 1.2 MPa. After cutting off the excess portion, a pulp mold lid shown in FIG. 14 was obtained by punching.
The basis weight of the pulp mold lid was 455 g/m ² . The inner diameter of the pulp mold lid was 80 mm, which was approximately the same as the outer diameter of the container (paper cup) used for measuring 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 fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The pulp mold lid had an opening force (opening shock peak value) of 0.40 N/cm when the fitting was released. The size (outer diameter) of the pulp mold lid was approximately 82 mm, the thickness was approximately 0.7 mm, and the density was approximately 0.65 g/cm ³ . The same was true for Examples 2-2 to 2-16.

Example 2-2
50 parts by mass of eucalyptus bleached virgin pulp (LBKP, Canadian Standard Freeness (CSF): 500 mL), which is a hardwood pulp, and 50 parts by mass of bagasse bleached virgin pulp (Canadian Standard Freeness (CSF): 380 mL), which is a non-wood pulp. A pulp slurry was obtained. To 100% by mass of this pulp slurry, 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, and after stirring, the slurry concentration was adjusted to 0.7% by mass. Adjusted to. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14.

Example 2-3
A pulp mold lid having the shape shown in FIG. 14 was obtained in the same manner as in Example 2-1 except that the eucalyptus bleached virgin pulp was replaced with acacia bleached virgin pulp.

Example 2-4
A pulp mold lid having the shape shown in FIG. 14 was obtained in the same manner as in Example 2-2 except that the eucalyptus bleached virgin pulp was replaced with acacia bleached virgin pulp.

Example 2-5
A pulp mold lid having the shape shown in FIG. 14 was obtained in the same manner as in Example 2-1 except that the Canadian standard freeness (CSF) of the bleached eucalyptus virgin pulp was changed to 350 mL.

Example 2-6
A pulp mold lid having the shape shown in FIG. 14 was obtained in the same manner as in Example 2-1 except that the Canadian standard freeness (CSF) of the bleached eucalyptus virgin pulp was changed to 250 mL.

Example 2-7
The figure was prepared in the same manner as in Example 2-1, except that the eucalyptus bleached virgin pulp (LBKP, Canadian Standard Freeness (CSF): 500 mL) was replaced with bagasse virgin pulp (Canadian Standard Freeness (CSF): 250 mL). A pulp mold lid having the shape shown in No. 14 was obtained.

Example 2-8
The shape shown in FIG. 14 was the same as in Example 2-2, except that the Canadian standard freeness (CSF) of the eucalyptus bleached virgin pulp was changed to 250 mL, and the Canadian standard freeness (CSF) of the bagasse bleached virgin pulp was changed to 250 mL. A pulp molded lid was obtained.

Example 2-9
45 parts by mass of eucalyptus bleached virgin pulp (LBKP, Canadian Standard Freeness (CSF): 500 mL), which is a hardwood pulp, 5 parts by mass of waste paper pulp (Canadian Standard Freeness (CSF): 500 mL), and bagasse bleached virgin pulp. (Canadian Standard Freeness (CSF): 380 mL) was mixed with 50 parts by mass to obtain a pulp slurry. To 100% by mass of this pulp slurry, 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, and after stirring, the slurry concentration was adjusted to 0.7% by mass. Adjusted to. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14. Externally, there were a few black spots that appeared to be from the waste paper.

Example 2-10
Same as Example 2-1 except that eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL) was changed to radiata pine bleached virgin pulp (NBKP, Canadian standard freeness (CSF): 380 mL) A pulp mold lid having the shape shown in FIG. 14 was obtained.

Example 2-11
Mix 50 parts by mass of radiata pine bleached virgin pulp (NBKP, Canadian Standard Freeness (CSF): 380 mL), which is a softwood pulp, and 50 parts by mass of bagasse bleached virgin pulp (Canadian Standard Freeness (CSF): 250 mL). A pulp slurry was obtained. To 100% by mass of this pulp slurry, 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, and after stirring, the slurry concentration was adjusted to 0.7% by mass. Adjusted to. Using the slurry, adjust the depth and width of the protrusion so that the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) is 1.5 N/cm. Similarly to Example 2-1, a pulp mold lid having the shape shown in FIG. 14 was obtained.

Example 2-12
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL), which is a hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer, (manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 5.0% by mass. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14.

Example 2-13
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL), which is a hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer, (manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 2.5% by mass. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14.

Example 2-14
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL), which is a hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer, (manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 0.5% by mass. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14.

Example 2-15
Eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL), which is a hardwood pulp, is made into a pulp slurry, and AKD (alkyl ketene dimer, (manufactured by Seiko PMC Co., Ltd.) was added in an amount of 0.8% by mass, and after stirring, the slurry concentration was adjusted to 0.3% by mass. Using the slurry, as in Example 2-1, the fitting force (fitting shock peak value) when fitting the pulp mold lid to the container (paper cup) was 1.5 N/cm. The depth and width of the convex portion were adjusted to obtain a pulp mold lid having the shape shown in FIG. 14.

Example 2-16
Figure 14 is the same as in Example 2-1 except that eucalyptus bleached virgin pulp (LBKP, Canadian standard freeness (CSF): 500 mL) was changed to bamboo bleached virgin pulp (Canadian standard freeness (CSF): 500 mL). A pulp molded lid having the shape shown in was obtained.

[Evaluation and analysis]
The following evaluations and analyzes were performed on the raw material pulps, pulp mold lids, and reference example plastic lids of the Examples and Comparative Examples described above. The results are shown in Tables 1 and 2.

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

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

(thickness and density)
The thickness and density of the pulp mold lid were measured according to JIS P 8118:2014.

(Mating force)
The fitting force of pulp mold lids or plastic lids was measured as follows. First, a pulp mold lid or plastic lid and a container (commercially available paper cup, outer diameter approximately 80 mm) are placed in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%) for 24 hours. It was left to stand, and the temperature and humidity were controlled. Thereafter, a pulp mold lid or a plastic lid was placed above the open end of the container, horizontally to the top of the open end, and a load was applied in the vertical direction at a speed of 100 mm/min (see FIG. 2). The maximum load value (fitting shock peak value) when the pulp mold lid or plastic lid was fitted to the open end of the container was defined as the fitting force.

(Opening force)
The opening force of pulp mold lids or plastic lids was measured as follows. First, a container (commercially available paper cup, outer diameter: approximately 80 mm) fitted with a pulp mold lid or a plastic lid is placed in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%). was allowed to stand for 24 hours, and the temperature and humidity were controlled. Thereafter, an L-shaped jig was hooked to the lower end of the outer peripheral edge of the pulp mold lid or plastic lid fitted to the open end of the container, and the lid was pulled up at a speed of 300 mm/min (see FIG. 3). The opening force was defined as the load value (opening shock peak value) when the pulp mold lid or plastic lid was released from the container.

(Surface convexity height Sp, surface convexity difference Sp+Sv absolute value)
Measurement was performed according to ISO 25178 using a 3D shape measuring machine VR-3000 (KEYENCE) and a compatible head VR-3200.
The pulp mold lids produced in each of the Examples and Comparative Examples were prepared and left for 24 hours in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%), and the temperature and temperature were controlled. I did the humidification. Measurement locations (10 mm x 10 mm: 10 locations) on each lid were randomly selected, and measurements were performed at a magnification of 40x in the above environment. Note that the surface of the lid that is visible on the paper in FIGS. 12 to 14 is the outer surface, and the measurements were performed on the outer surface.
Observation and analysis were performed using the following software.
Observation application (VR-H2V) (KEYENCE)
Analysis application (VR-H2A) (KEYENCE)
At each measurement location, using the heights of the surface protrusions Sp1, Sp2, Sp3...Sp10 on the outer surface and the depths Sv1, Sv2, Sv3...Sv10 of the outer surface recesses, the following formula is used. I calculated it.
Height of surface convexity Sp=(Sp1+Sp2+Sp3+...+Sp10)/10 (1)
Depth of surface recess Sv=(Sv1+Sv2+Sv3+...+Sv10)/10 (2)

(Evaluation regarding liquid spillage)
Fill a container (commercially available paper cup, outer diameter: approximately 80 mm, height: 90 mm) with 100% orange juice up to approximately 10 mm from the top, fit it with a pulp mold lid or plastic lid, and tilt the container. This state was maintained for 10 seconds, and the presence or absence of outflow of fruit juice was checked, and evaluation was performed using the following method.
A: There is no outflow or exudation of fruit juice.
B: There is no outflow of fruit juice, but the fruit juice oozes out slightly.
C: There is no outflow of fruit juice, but the fruit juice oozes out to an extent that poses no practical problem.
D: There is outflow of fruit juice.

(Evaluation regarding ease of opening)
The ease of opening a container (commercially available paper cup, outer diameter: approximately 80 mm) fitted with a pulp mold lid or a plastic lid by hand was evaluated using the following method.
A: It can be opened without resistance.
B: There is some resistance, but it can be opened without any problem.
C: There is resistance and the seal can be opened by applying strong force, so there is no problem in practical use.
D: There is considerable resistance, and if you try to open the container with too much force, problems may occur such as the contents of the container spilling out.

(Smooth feeling)
Ten pulp mold lids produced in each example and comparative example were prepared and left for 24 hours in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%). Temperature and humidity were controlled.
The front and back sides of the pulp mold lid were touched in the above environment and evaluated as follows.
5: Very smooth and smooth.
4: Slight fibers are felt on the surface, but it is smooth.
3: There is a feeling of smoothness, but there are many fibers on the surface.
2: There is a feeling of smoothness, but there are a lot of fibers on the surface.
1: There is no smooth feeling and the texture is rough.
Below the 0:1 level.
The numbers in the table are the average values of 10 (decimal points are rounded off).

(Oil resistance)
200 mL of a test solution (equivalent to the formulation of kit number 6 of JAPAN TAPPI No. 41:2000) was prepared at a ratio of castor oil/toluene/heptane = 50/25/25 and used in the experiment.
Five pulp mold lids produced in each example and comparative example were prepared and left for 24 hours in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%). Temperature and humidity were controlled. In the above environment, apply the above test solution to the back (inner surface) of the pulp mold lid from a height of 25 mm using a reagent bottle dropper (reagent bottle similar to JAPAN TAPPI No. 41:2000) and apply 1 liter to the horizontal part of the lid. The drop was dropped and observed from the front (outer surface) of the pulp mold lid 15 seconds later.
4: No liquid penetration was observed on the surface of the lid. 3: A small amount of liquid penetration was observed on the surface of the lid, but the area was less than 15% of the spread of the liquid on the back. 2: Liquid penetration was observed on the front side of the lid, and the area exceeded 15% and was less than 50% of the spread of liquid on the back side. 1: Liquid penetration was observed on the front side of the lid, and the area was The number in the table is the average value of five (decimal points are rounded off).

(Texture)
Five pulp mold lids prepared in Examples 2-1 to 2-16 were prepared and left for 24 hours in an environment compliant with ISO 187:1990 (temperature 23 ± 1°C, relative humidity 50 ± 2%). Then, the temperature and humidity were adjusted. The lid was placed over a paper cup, and the lid was placed against the mouth as if drinking water through the opening in the above-mentioned environment, and the feel of the lid upon contact with the mouth was evaluated.
5: There is no feeling of the fibers touching the mouth, and there is no discomfort at all.
4: There is a slight feeling that the fibers are touching the mouth, but there is no discomfort.
3: The fibers touch the mouth, but not so much that it makes you feel uncomfortable.
2: The fibers hit the mouth and it felt a little strange.
1: The fibers touch the mouth and there is a feeling of discomfort.
The numbers in the table are the average values of five (decimal points are rounded off).

As can be seen from Tables 1 and 2, the pulp mold lid of the present invention achieves both ease of closing and ease of opening by having a fitting force or an opening force within a predetermined range, and is able to fit easily under normal use. The state can be maintained. Further, according to the pulp mold lid of the present invention, the height of the surface convexity or the absolute value of the difference in surface unevenness is equal to or less than a predetermined value, so that the lid has excellent oil resistance and surface smoothness.

The pulp mold lid of the present invention is both easy to close and easy to open, and can maintain a fitted state during normal use, so it is suitable for lids for containers such as paper cups and other beverage containers. .

100, 110, 120, 200, 210: Pulp mold lid, 10: Top, 11: First slope, 12: Second slope, 13: Third slope, 14: Fourth slope, 15: Concave step part, 15A: first recess step, 15B: second recess step, 15C: third recess step, 17: drinking spout, 19: through hole, 30: outer peripheral edge, 31: (outer peripheral edge) Lower end, 33: Convex portion, 34: Groove portion, 35: Flange portion, 37: Chamfered portion, 1: Container, 3: Open end portion, 5: Upper end (of the open end portion), N: L-shaped jig, H: Height of the protrusion, W: Width of the protrusion

Claims (17)

A pulp mold lid comprising a top portion and an outer peripheral edge portion depending from the outer peripheral edge of the top portion, and capable of being fitted onto and unfitted from an open end of a container,
The density of the pulp mold lid is 0.45 g/cm ³ or more and 0.65 g/cm ³ or less,
A pulp mold lid that meets requirement 2 below.
Requirement 2: An L-shaped jig is hooked to the lower end of the outer peripheral edge of the pulp mold lid fitted to the open end of the container and pulled up at a speed of 300 mm/min, and the load is when the fitting is released. The opening force, which is a value, is 0.15 N/cm or more and 0.41 N/cm or less. The pulp mold lid according to claim 1, which further satisfies the following requirement 1.
Requirement 1: Place the pulp mold lid above the open end of the container horizontally to the upper end of the open end, apply a load in the vertical direction at a speed of 100 mm/min, and place the pulp mold lid above the open end of the container. The fitting force, which is the maximum load value when fitted, is 0.6 N/cm or more and 1.5 N/cm or less. The pulp mold lid according to claim 1 or 2, wherein the outer peripheral edge portion includes a convex portion that fits into the open end portion. The pulp mold lid according to any one of claims 1 to 3, wherein the top portion includes a recessed step portion. The pulp mold lid according to any one of claims 1 to 4, wherein the outer peripheral edge portion includes a flange portion. The pulp mold lid according to any one of claims 1 to 5, which satisfies at least one of the following requirements 3 and 4.
Requirement 3: The height Sp (ISO 25178) of the surface convexity on at least one of the outer surface and inner surface of the pulp mold lid is 80 μm or less.
Requirement 4: The absolute value of the surface unevenness difference Sp+Sv (ISO 25178) on at least one of the outer surface and inner surface of the pulp mold lid is 100 μm or less. The pulp mold lid according to claim 6, which satisfies both requirements 3 and 4 above. The pulp mold lid according to any one of claims 1 to 7, wherein the pulp raw material for the pulp mold lid contains 80% by mass or more of virgin pulp. The pulp mold lid according to any one of claims 1 to 8, wherein the pulp raw material for the pulp mold lid is a mixed pulp of wood pulp and non-wood pulp. The pulp mold lid according to any one of claims 1 to 9, wherein the pulp constituting the pulp mold lid has a Canadian standard freeness of 100 mL or more and 700 mL or less. The pulp mold lid according to any one of claims 1 to 10 , wherein the pulp mold lid has a one-layer structure. The pulp mold lid according to any one of claims 1 to 11 , wherein the container is a beverage container. The pulp mold lid according to any one of claims 1 to 12 , wherein the top portion includes at least one of a drinking spout and a notch. The pulp mold lid according to any one of claims 1 to 13 , wherein the container is a paper cup. A method for producing a pulp mold lid according to any one of claims 1 to 14 ,
a pulp suspension preparation step of preparing a pulp suspension;
a papermaking step for producing pulp from a pulp suspension through a papermaking die;
A hot press in which the mold intermediate obtained after the papermaking step is heated and hot-pressed by a first press mold and a second press mold located in the opposite direction to the first press mold. A method for manufacturing a pulp mold lid, comprising the steps of: The method for manufacturing a pulp mold lid according to claim 15 , wherein the pressure in the hot pressing step is 0.1 MPa or more and 3.0 MPa or less. The method for manufacturing a pulp mold lid according to claim 15 or 16 , wherein the temperature in the hot pressing step is 130°C or more and 280°C or less.