JP2002363899A - Pulp mold base and gas barrier container using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an environment-conscious gas barrier container which is a pulp mold container having high degree of shape freedom and having no fold and seam, has stable gas barrier properties equal to or higher than conventional gas barrier paper containers molded by folding up and laminating a paperboard on which aluminium foil, a deposited film of a metallic oxide, etc., is laminated and retains biodegradability and recyclability as a paper container. SOLUTION: This pulp mold base is characterized by having >=60 s air permeability measured by JIS P8117, >=2 s smoothness measured by JIS P8119 on at least one surface and <=6.3 μm arithmetic-average roughness defined by JIS B0601 (when cutoff value is 2.5 mm and evaluated length is 12.5 mm).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container mainly comprising a pulp mold, and more particularly to a gas barrier container having a high gas barrier property without significantly impairing the recyclability and biodegradability of pulp fibers.

[0002]

2. Description of the Related Art In recent years, with increasing environmental awareness, paper containers have begun to be widely used in fields where plastic containers and metal containers are mainly used, for example, in the fields of toiletry-related products, beverages and foods. I have. For example, paper containers coated with polyethylene resin on both sides of paper and formed into a hexahedral container or a roof-type container called a gable top, or a paper container formed into a cup shape are already generally used. However, since the paper container as described above is formed by bending and bonding paperboard, there is no degree of freedom in the shape, and it is difficult to sufficiently express the uniqueness of the product. In addition, since a step is always generated in the bonded portion, when the container is sealed with a lid material, poor sealing is likely to occur.

[0003] One means for giving a paper container a degree of freedom is a pulp mold. The container made of the pulp mold is generally produced by suction-dewatering a pulp material on a mold in a wet method, and then drying it in a drying furnace or a heating mold. In particular, when dimensional stability and aesthetics are required, the pulp is manufactured by sucking and dehydrating pulp on a papermaking mold, and then heating and drying in a press mold that fits each other. Further, Japanese Unexamined Patent Application Publication No. 11-3
According to the manufacturing method described in Japanese Patent No. 14267, a hollow shape such as a bottle shape can also be molded. The pulp mold container manufactured in this way has a high degree of freedom in shape and does not have a bonded portion, so that a high value-added product can be provided.

On the other hand, paper containers are required to have a gas barrier property against water vapor, oxygen and the like in order to maintain the quality of the contents. In the case of a container which is formed by folding and bonding a conventional paperboard, it is possible to form the film after bonding an aluminum foil or a vapor-deposited film of a metal oxide having a gas barrier property such as SiO _X or Al ₂ O ₃ to the paper. However, the pulp mold container obtained as described above has a difficulty in forming a gas barrier layer due to its complicated three-dimensional shape. In addition, paper containers formed from conventional paperboard may cause defects in the gas barrier layer at the bent portion or the bonded portion, which may cause deterioration of the quality of the contents, and the gas barrier layer has high gas barrier properties without folds or seams. There is a need for a paper container having the same.

[0005] Accordingly, we have filed Japanese Patent Application No. 2000-102600.
In the specification, a pulp mold container in which a gas barrier property is imparted by forming a thin film by plasma polymerization on the surface of a pulp mold is proposed. When forming a thin film by plasma polymerization, that is, a thin film by plasma-assisted CVD (chemical vapor deposition), the shape of the discharge electrode is designed according to the shape of the pulp mold container, and is stable on the inner surface and / or outer surface of the container. By generating the generated plasma, a seamless and uniform thin film can be formed on the three-dimensional surface.

Further, in order to monitor the porous and non-uniform surface of the pulp mold base material, the inner surface of the pulp mold container or / and the inner surface of the pulp mold container are spray-coated or dipped.
Further, by coating a filler on the outer surface and then forming a thin film by plasma polymerization, more stable barrier properties can be obtained. However, a thick resin layer is required to completely fill the uneven pulp mold surface, which makes drying difficult, and causes problems such as dripping, bubbles, and foaming due to the formation of a dry film on the surface layer. It was easy to occur. Further, the film quality of the thin film formed by plasma polymerization changes depending on the surface state of the filling layer and the type of the resin, and greatly affects the gas barrier property of the thin film. For these reasons, the gas barrier property of a pulp mold container in which a thin film is formed by conventional plasma polymerization is expressed in terms of surface area,
Oxygen permeability was about 20 cc / m ² / day and water vapor permeability was about 10 g / m ² / day, indicating that the gas barrier properties were not sufficient.

[0007]

However, when a similar thin film is formed on a polyethylene terephthalate (PET) sheet by plasma polymerization, the oxygen permeability becomes 1 cc / m 2.
A gas barrier property of ² / day and a water vapor permeability of 1 g / m ² / day is obtained. Therefore, as long as a plasma-polymerized thin film of good film quality is formed, it is considered that a high gas barrier property can be obtained even in a pulp mold container, and as a result of intensive studies, the surface condition of the pulp mold base material and the sealing layer It was concluded that it was important to control the surface condition of the sample comprehensively.

The present invention relates to a pulp mold container having a high degree of freedom in shape and having no folds or seams, wherein a conventional paperboard on which an aluminum foil or a metal oxide vapor-deposited film is bonded is formed by bending and bonding. An object of the present invention is to provide an environment-friendly gas barrier container having a stable high gas barrier property equal to or higher than that of a gas barrier paper container and not impairing the biodegradability and recyclability of the paper container.

[0009]

Means for Solving the Problems The invention of claim 1 is a JI.
The air permeability measured according to SP8117 is 60 seconds or more, and JIS P811
9 and a smoothness of 2 seconds or more according to JIS
Arithmetic average roughness defined by B0601 is 6.3 μm
The following (cutoff value is 2.5 mm, evaluation length is 12.5
mm).

According to a second aspect of the present invention, at least one or more filler layers are provided by coating a filler on the inner surface and / or the outer surface of the pulp mold base material, and a thin film is formed thereon by plasma polymerization. A gas barrier container, wherein the pulp mold substrate is JIS P8117.
The air permeability measured in accordance with JIS is 60 seconds or more, and the smoothness of the surface of the pulp mold substrate on which the thin film layer is formed by plasma polymerization is 2 seconds or more as measured according to JISP8119, and JIS A gas barrier container characterized in that the arithmetic average roughness defined by B0601 is 6.3 μm or less (cutoff value is 2.5 mm, evaluation length is 12.5 mm).

The invention according to claim 3 is that the sealing layer is made of an olefin-based, amide-based, petroleum-based, rosin-based, ester-based,
3. The resin layer according to claim 2, wherein the resin layer is mainly composed of any one or more of epoxy, isocyanate, polyvinyl alcohol, acrylic, vinyl acetate, butadiene, urethane, and polysaccharide. Gas barrier container.

According to a fourth aspect of the present invention, in the case where the sealing layer is composed of a plurality of layers, the sealing layer on the side of the interface with the thin film formed by plasma polymerization is a resin mainly composed of a styrene-acryl copolymer resin. The gas barrier container according to claim 2, wherein the container is a layer.

The invention of claim 5 is a multilayer structure in which the filling layer includes at least a resin layer mainly composed of a resin having biodegradability and a resin layer mainly composed of a styrene / acrylic copolymer resin. The gas barrier container according to claim 4, characterized in that:

According to a sixth aspect of the present invention, the thin film formed by the plasma polymerization is silica-based.
6. The gas barrier container according to any one of 5.

[0015]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a layer structure of a container as one embodiment of the present invention. The gas barrier container (1) of the present invention shows an example in which the plasma polymerized thin film layer (4) is formed on the inner surface of the pulp mold substrate (2) via the sealing layer (3).

In order for a thin film formed by plasma polymerization to exhibit a stable and high gas barrier property, it is necessary to form a uniform continuous film having good film quality. Therefore, the physical and chemical surface state of the sealing layer surface (31) serving as the base of the thin film greatly affects the barrier property of the thin film.

First, the physical surface formation of the filler layer surface (31) is greatly affected by the coating conditions of the filler and the surface condition (21) of the pulp mold substrate (2).
When the coating amount of the filler is large, the surface is likely to be disturbed due to dripping or foaming. On the other hand, if the swell of the pulp mold substrate surface (21), the density of pulp fibers, or the gap between fibers is large, this is reflected and the filling layer surface (31) is reflected.
And the required thickness of the sealing layer (3) also increases. In addition, defects such as bubbles and pinholes are generated in the sealing layer (3) due to the protrusion of the fibers on the pulp mold substrate surface (21) and the fine roughness. Therefore, from the macro level surface smoothness of the pulp mold base material surface (21) such as undulation, density of pulp fibers, voids between fibers, etc., micro level such as fiber protrusion and fine roughness. It can be said that controlling the surface smoothness is important for achieving high gas barrier properties of the thin film by plasma polymerization.

Therefore, one of the important features of the present invention is that the surface layer of the pulp mold substrate is dense, the surface of the pulp mold substrate has high smoothness, and the surface roughness is small. The material (2) has an air permeability of at least 60 seconds measured according to JIS P8117, and the pulp mold substrate surface (21) has a smoothness of at least 2 seconds measured according to JIS P8119 and JIS B0601.
Arithmetic average roughness defined by 6.3 μm or less (cutoff value is 2.5 mm, evaluation length is 12.5 mm)
The method is characterized in that a filler is coated on the surface (21) to form a filler layer (3), and a thin film layer (4) is formed thereon by plasma polymerization.

By defining the surface condition of the pulp mold base material as described above, the physical surface condition of the filling layer surface (31) can be favorably formed. At the same time, the required film thickness of the sealing layer (3) is also reduced, so that drying during coating of the sealing agent is facilitated, defects such as dripping, bubbles, and foaming are less likely to occur, and a more stable thin film layer formed by plasma polymerization. (4) can be formed.

As a specific method for making the pulp mold base material surface (21) dense and smooth as described above, a high-pressure mechanically is used in a mold having a smooth surface during or after pulp molding. Pressing, and from the material side, use of pulp with low freeness, use of fine pulp, and hydrolysis of alkoxysilane to increase the number of bonding points without disturbing hydrogen bonding between fibers By internally adding an internal additive whose main component is a product, the pulp mold substrate surface (21) shown above is obtained.

The material and molding method of the pulp material are not limited as long as the pulp mold substrate (2) applicable to the present invention satisfies the above characteristics. In addition, as long as the object of the present invention does not impair the gas barrier properties, biodegradability, and recyclability, general papermaking additives, such as sizing agents, paper strength agents, fillers, and resin pulp. Etc. may be added.

Another important feature of the present invention is that
The effect of the chemical surface state of the sealing layer surface (31) on the formation of good film quality for the thin film to exhibit high gas barrier properties by plasma polymerization is large, that is, the sealing layer (3) and the thin film layer (4). It is important to note that the matching layer is important. Specifically, the sealing layer (3) is made of olefin, amide, petroleum, rosin, ester, epoxy, isocyanate, or polyvinyl alcohol. , Acrylic, vinyl acetate, butadiene, urethane,
A resin layer containing any or a plurality of polysaccharides as a main component, particularly preferably at least a sealing layer on an interface with a thin film formed by plasma polymerization, is mainly composed of a styrene-acryl copolymer resin. Is to be a resin layer.

The filler layer (3) can be provided by dip coating or spray coating an aqueous solution, an organic solvent-based solution, or an emulsion-based filler on the pulp mold substrate surface (21) described above. it can. However, it is preferable to use an aqueous solution or an emulsion as a filler from the viewpoint of the working environment. Filling layer (3)
Can be appropriately set depending on the surface condition of the pulp mold base material (2) and the type of filler, but is preferably 5 to 50 g / m ² . If it is less than 5 g / m ^{2, the} filling of the pulp mold base material surface is insufficient, and it is difficult to obtain high gas barrier properties. Conversely, if it exceeds 50 g / m ² ,
As described above, defects such as dripping, bubbles, foaming, and the like are likely to occur in the sealing layer, and the gas barrier properties are rather reduced, and the recyclability and biodegradability of the paper container are easily hindered.

In particular, styrene.
When a resin containing an acrylic copolymer resin as a main component is used as a sealing layer at least on the interface with the thin film formed by plasma polymerization, good adhesion to the thin film layer (4) is obtained, and particularly, a high gas barrier property is obtained. A film of plasma polymerized thin film is formed. Although the chemical action mechanism is not clear yet, the stability of the styrene-acrylic copolymer resin against heat and moisture and the hydrophobic group derived from the styrene component contribute to the formation of a film with high gas barrier properties. We consider that there is.

Further, the styrene / acrylic copolymer resin is
Although it is water-resistant, it is soluble in alkali, so it has the advantage that it is dissolved by the alkali added in the defibration step when recycled as recycled paper and does not impair the defibration of pulp fibers.

Further, in the gas barrier container according to claim 4 of the present invention, as shown in FIG. 2, the structure of the container as one embodiment thereof is such that the sealing layer (3) and the first sealing layer (32) are formed. By dividing into the second sealing layer (base of the thin film by plasma polymerization) layer (33), a resin having a good matching with the thin film layer by plasma polymerization (4) is provided on the second sealing layer (33),
By providing a biodegradable or alkali-soluble resin in the first sealing layer (32), it is possible to maintain biodegradability and recyclability as a paper container while having high gas barrier properties.

The formation of the thin film layer (4) by plasma polymerization is performed by preparing a discharge electrode conforming to the shape of the pulp mold substrate (2) and supplying a monomer gas as exemplified below.
By supplying appropriate power under a pressure of about 1 to 10 Pa, stable discharge plasma is generated on the inner surface and / or outer surface of the pulp mold container, and the treatment is performed for a predetermined time.

There is no particular limitation on the thin material formed by plasma polymerization, and examples thereof include silica-based, fluorine-based, and carbon-based materials. Among them, silica is particularly preferable because a thin film can be formed at a high rate by plasma polymerization and relatively easily. When the silica-based thin film contains 5% or more of carbon atoms, the permeability of water vapor passing through the film can be reduced.

As the monomers used for forming the silica-based thin film, 1,1,3,3-tetramethyldisiloxane, hexamethyldisiloxane, vinyltrimethylsilane, methyltrimethoxysilane, hexamethyldisilane, methylsilane, Dimethylsilane, trimethylsilane, diethylsilane, propylsilane, phenylsilane, vinyltriethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane,
From among phenyltrimethoxysilane, methyltriethoxysilane, octamethylcyclotetrasiloxane, etc.
It can be selected depending on the compatibility with the sealing layer (3) and the required gas barrier property, and in particular, 1,1,3,3, -tetramethyldisiloxane, hexamethyldisiloxane,
Octamethylcyclotetrasiloxane is preferred. However, the present invention is not limited to these, and aminosilane, silazane, or the like can be used. The organic silicon compound, which is a liquid, is vaporized and, if necessary, mixed with a gas having an oxidizing power such as oxygen or carbon dioxide or a rare gas such as argon or helium.

On the other hand, monomers used for polymerizing a carbon-based thin film include, for example, alkanes such as methane, ethane, propane, butane, pentane and hexane; alkenes such as ethylene, propylene, butene, pentene and butadiene; and acetylene. Such as alkynes, aromatic hydrocarbons such as benzene, toluene, xylene, and naphthalene;
Cyclopropane, cycloparaffins such as cyclohexane, cyclopentene, cycloolefins such as cyclohexene, carbon monoxide, carbon dioxide, methyl alcohol,
Oxygen-containing carbon compounds such as ethyl alcohol and nitrogen-containing carbon compounds such as methylamine, ethylamine and aniline can be used. These gases may be used alone, or may be used as a mixture with a rare gas such as argon or helium.

So far, the case where the sealing layer (3) and the thin film layer (4) formed by plasma polymerization are formed on the inner surface of the container has been described. The inner surface, the outer surface, or both surfaces may be used. Although not shown in the drawings, the pulp mold base material layer (2) or the thin film layer (4) formed by plasma polymerization
A protective coat layer, a heat seal layer, a print layer, and the like can be provided on the top. Regarding the shape, tray,
The shape is not particularly limited as long as it can be shaped into a pulp such as a bowl or a bottle.

[0033]

The gas barrier container of the present invention will be described in detail with reference to the following examples.

<Examples 1 to 5> Using hardwood bleached kraft pulp (LBKP) beaten to 300 csf as a raw material,
Alkyl ketene dimer (AKD) was added as a sizing agent in an amount of 0.5% based on the weight of the dry pulp to obtain a 0.4% pulp slurry. 4 L of this pulp slurry was suction-dehydrated on a female mold to obtain a mold intermediate, which was then heated and dried in a press mold fitted to each other to obtain a pulp mold base material as shown in FIG. At this time, the press mold has a suction hole on the female mold side, the surface of the male mold is smooth, and the mold temperature is 160
The pulp mold substrates of Examples 1 to 5 shown in Table 1 were obtained by changing the temperature, press pressure, and press time. For samples sampled from the bottom and sides of this pulp mold base material, the air permeability, the smoothness of the inner surface of the pulp mold base material, and the arithmetic average roughness were determined by the following methods, and the respective average values are shown in Table 1. Was.

Regarding the measurement of the air permeability, see JIS P81
Gurley's Densometer according to 17
(Toyo Tester Co., Ltd.) measured the air permeability. Regarding the measurement of the smoothness, according to JIS P8119, BE
The smoothness on the inner surface side of the container was measured by KK SMOOTHNESSTESTER (manufactured by Kumagaya Riki Kogyo Co., Ltd.). Regarding the measurement of the surface roughness, in accordance with JIS B0601,
With a surface roughness profile measuring machine Surfcom (manufactured by Tokyo Seimitsu Co., Ltd.), the cutoff value is 2.5 mm and the evaluation length is 12.5.
The arithmetic average roughness on the inner surface side of the container was measured in mm.

A styrene-acrylic copolymer resin emulsion (Johncryl 352, manufactured by Johnson Polymer Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of Example 1 to form an acrylic-based acrylic resin having a coating amount of 20 g / m ² . Was provided. Further, using hexamethyldisiloxane (hereinafter abbreviated as HMDSO) as a monomer, a film thickness of 3 is formed on the inner surface of the container by plasma polymerization in a mixed atmosphere with oxygen.
A gas barrier container of Example 1 was obtained by providing a silica-based thin film of 0 nm.

A styrene / acrylic copolymer resin emulsion (Johncryl 352 manufactured by Johnson Polymer Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of the above-mentioned Example 2, and an acrylic resin having a coating amount of 20 g / m ² was applied. Was provided. Thereafter, in the same manner as in Example 1, a silica-based thin film was provided to obtain a gas barrier container of Example 2.

On the inner surface of the pulp mold substrate of Example 3, a polyvinyl alcohol resin (Kuraray Co., Ltd. 11
Spray-coating a 10% solids aqueous solution of the above (1) to form a polyvinyl alcohol-based first sealing layer having a coating amount of 15 g / m ² , and further forming a styrene / acrylic copolymer resin emulsion (Johnson Polymer Co., Ltd.) Spray coated with Joncryl 352) manufactured by Co., Ltd., and coated at 5 g / m
² provided with the second eye filling layer of the acrylic. Example 1 below
Similarly to the above, a silica-based thin film was provided to obtain a gas barrier container of Example 3.

A polyester resin emulsion (Vylonal MD1200, manufactured by Toyobo Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of Example 4 above.
An ester-based sealing layer having a coating amount of 20 g / m ² was provided.
Thereafter, in the same manner as in Example 1, a silica-based thin film was provided and
Was obtained.

An aqueous dispersion of modified starch (Randy CP manufactured by Miyoshi Yuka Co., Ltd.) was added to the pulp mold substrate of Example 5 above.
100S) was dipped and dried in an oven, and then hot-pressed in the above-mentioned male and female molds at 120 ° C. and a pressure of 0.5 MPa for 30 seconds to provide a polysaccharide-based sealing layer. Thereafter, in the same manner as in Example 1, a silica-based thin film was provided to obtain a gas barrier container of Example 5.

<Comparative Examples 1 to 4> In the same manner as in the above Examples, the pulp mold substrates of Comparative Examples 1 to 4 shown in Table 1 were obtained by changing the pressing pressure and the pressing time. About the sample sampled from the bottom part and the side part of this pulp mold base material, the air permeability was measured in accordance with JIS P8117 in the same manner as the pulp mold base material of the above example,
Measure the smoothness of the inner surface side of the container according to SP8119,
Further, the arithmetic average roughness defined by JIS B0601 on the inner surface side of the container was determined, and the respective average values are shown in Table 1.

A styrene-acrylic copolymer resin emulsion (Johncryl 352 manufactured by Johnson Polymer Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of Comparative Example 1, and an acrylic-based acrylic resin having a coating amount of 20 g / m ² was used. Was provided. Thereafter, in the same manner as in Example 1, a silica-based thin film was provided to obtain a container of Comparative Example 1.

A styrene-acrylic copolymer resin emulsion (Johncryl 352 manufactured by Johnson Polymer Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of Comparative Example 2, and an acrylic-based acrylic resin having a coating amount of 20 g / m ² was used. Was provided. Thereafter, similarly to Example 1, a silica-based thin film was provided to obtain a container of Comparative Example 2.

A polyester resin emulsion (Vylonal MD1200 manufactured by Toyobo Co., Ltd.) was spray-coated on the inner surface of the pulp mold base material of Comparative Example 3 above.
An ester-based sealing layer having a coating amount of 20 g / m ² was provided.
Thereafter, similarly to Example 1, a silica-based thin film was provided and Comparative Example 3 was provided.
Container was obtained.

A silica-based thin film having a thickness of 30 nm was formed on the inner surface of the pulp mold base material of Comparative Example 4 by plasma polymerization in a mixed atmosphere of HMDSO as a monomer and oxygen to obtain a container of Comparative Example 4. .

<Comparative Example 5> A cup-shaped paper container having the shape shown in FIG. 3 was prepared from the laminated sheet having the following structure, and a container of Comparative Example 5 was obtained. Low density polyethylene (20μm) /
Paper (300 g / m ² ) / ionomer (20 μm) / S
iOx evaporated thin film (40 nm) / biaxially stretched polyethylene terephthalate (12 μm) / low density polyethylene (50
μm)

[0047]

[Table 1]

A heat seal lacquer was applied to the openings of the containers of Examples 1 to 4 and Comparative Examples 1 to 4, 100 g of calcium chloride was filled, and a laminate film containing an aluminum foil was heat-sealed to the openings of the containers. Sealed. These were stored in an environment of 40 ° C. and 90% RH, and the water vapor permeability of the container was determined from the weight increase. Table 2 shows the water vapor transmission rate calculated from the surface area of the container.

[0049]

[Table 2]

As apparent from Table 2 above, Examples 1 to 5
Has a water vapor permeability of 5 g / m ^Two/ Day and below
Excellent gas barrier properties, gas barrier film on paperboard,
Same as folded paper container (Comparative Example 5)
It showed gas barrier properties equal to or higher than that. Without folds or seams
Gas barrier properties are stable, and even when sealing lid materials
Because there are no steps, the gas barrier properties are further improved
I can think.

Further, Example 3, Example 5, Comparative Example 1,
The container of Comparative Example 5 was buried in the field soil at a depth of 10 cm, and the state of decomposition was observed. In the containers of Example 3 and Example 5, the containers were disintegrated after 5 months, all collapsed after 1 year, and the sample could not be collected. On the other hand, the containers of Comparative Examples 1 and 5 remained in the shape of the container even after one year. Cellulose, which is the main component of pulp fiber, is a biodegradable material by nature.However, if the non-biodegradable resin layer is thick, it cannot be disintegrated finely and must be in sufficient contact with microorganisms that degrade cellulose. It is considered that the residue did not decompose and remained in the environment. On the other hand, in the container of Example 3, the styrene / acrylic copolymer resin layer having no biodegradability was as thin as 5 g / m ² and the film strength was weak, so that it was finely divided and did not hinder the decomposition of the biodegradable material. It is inferred.

Further, the following evaluation of recyclability was performed on the assumption that the containers of the above Examples and Comparative Examples were put on a general used paper collection line. Sample 2 cut into 3cm square
0 g is placed in 1 L of a 2% aqueous sodium hydroxide solution at 80 ° C., and defibrated for 3 minutes with a small disintegrator (manufactured by Tester Sangyo Co., Ltd.) to separate the upper layer suspended matter, and after washing with water, hand paper machine. Hand-made paper. When the state and the recovery rate of the pulp fiber were calculated, in Comparative Example 5, large film pieces were mixed, and the recovery rate of the pulp fiber was as low as 60%. On the other hand, in Examples 1 to 5 and Comparative Examples 1 to 4 of the pulp mold container, the mixture of Example 4 and Comparative Example 3 in which a mixture of plastic pieces and agglomeration of fibers were observed, and others were able to make a clean recycled paper,
The fiber recovery was also 80% or more.

[0053]

As described above, the gas barrier container according to the present invention is a pulp mold container having a high degree of freedom in shape and having no folds or seams. By controlling the state of the layer surface layer comprehensively, it is possible to bend the paperboard on which the metal oxide vapor-deposited film, etc. is pasted, and to achieve superior gas barrier properties equivalent to or better than the conventional gas-barrier paper container molded by bonding. It is possible to provide an environment-friendly gas barrier container without deteriorating the biodegradability and recyclability of the paper material while having it. Therefore, it can be widely applied to fields where plastic containers and the like are conventionally used.

[0054]

[Brief description of the drawings]

FIG. 1 is a sectional view showing a configuration of a container as one embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a configuration of a container as one embodiment according to claim 4 of the present invention.

FIG. 3 is a cross-sectional view illustrating a container according to an embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Gas barrier container 2 Pulp mold base material 21 Pulp mold base material surface 3 Filler layer 31 Filler layer surface 32 First fill layer 33 Second fill layer (underlayer of thin film by plasma polymerization) 4 Thin film by plasma polymerization layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Tomoko Kato 1-5-1, Taito, Taito-ku, Tokyo Toppan Printing Co., Ltd. F-term (reference) 3E033 AA08 BA10 BA30 CA16 CA20 EA10 FA01 3E062 AA10 AB02 AC07 JA08 JB23 JC02 JC04 JD01 4L055 AA03 AC06 AG40 AG63 AG64 AG71 AG86 AG89 AH11 AH50 BF08 BF09 EA12 EA27 FA30 GA05

Claims (6)

[Claims] An air permeability measured according to JIS P8117 is 60 seconds or more, and at least one surface has
The smoothness is 2 seconds or more measured according to JIS P8119, and the arithmetic average roughness defined by JIS B0601 is 6.3 μm or less (cutoff value is 2.5 mm, evaluation length is 12.5 mm. A pulp mold substrate. 2. A gas-barrier container comprising a pulp mold substrate on which an inner surface and / or an outer surface is coated with a filler and at least one or more filler layers are provided, on which a thin film is formed by plasma polymerization. The pulp mold substrate has an air permeability measured according to JIS P8117 of 60 seconds or more, and the surface of the pulp mold substrate on which a thin film layer is formed by plasma polymerization is JIS
The smoothness is 2 seconds or more as measured according to SP8119, and the arithmetic average roughness defined by JIS B0601 is 6.3 μm or less (cutoff value is 2.5 mm, evaluation length is 12.5 mm. A gas barrier container characterized by the following. 3. The sealing layer according to claim 1, wherein the olefin-based, amide-based, petroleum-based, rosin-based, ester-based, epoxy-based, isocyanate-based, polyvinyl alcohol-based, acrylic-based,
The gas barrier container according to claim 2, wherein the resin layer is a resin layer containing any one or more of vinyl acetate, butadiene, urethane, and polysaccharide as main components. 4. When the sealing layer is composed of a plurality of layers, the sealing layer on the side of the interface with the thin film formed by plasma polymerization is a resin layer containing a styrene-acryl copolymer resin as a main component. The gas barrier container according to claim 2 or 3, wherein 5. The filling layer has a multilayer structure including at least a resin layer mainly composed of a resin having biodegradability and a resin layer mainly composed of a styrene / acrylic copolymer resin. The gas barrier container according to claim 4. 6. The gas barrier container according to claim 2, wherein the thin film formed by the plasma polymerization is a silica-based thin film.