JP6171674B2 - Sheet material and barrier packaging container - Google Patents

Description

  The present invention relates to a sheet material having a gas barrier property used in an electronic member as well as the packaging field of foods, pharmaceuticals, daily necessities and the like. In particular, the present invention relates to a sheet material having a gas barrier property that is excellent in water vapor barrier property and odor barrier property, and a packaging container using the same.

  In recent years, packaging materials used for packaging have to be handled in aseptic conditions in order to suppress the alteration of contents, especially the oxidation and alteration of proteins and fats in foods, and to maintain the taste and freshness. In order to suppress the alteration of the active ingredients and maintain the efficacy of the drugs that are used, it is necessary to prevent the influence of oxygen, water vapor, and other gases that alter the contents of the packaging material, and block these gases. It is required to have gas barrier properties. Furthermore, for toiletry products, detergents, and the like, packaging materials having odor barrier properties are being demanded as demands for odors diversify in recent years.

  Among them, many barrier films in which a metal oxide film such as silicon oxide or aluminum oxide is provided on a plastic substrate on a nano scale have been proposed as a barrier material against oxygen, water vapor, and the like in recent years.

  As a method of forming a metal oxide layer on the surface of a resin film, a physical vapor deposition method (PVD) such as a vacuum film forming method, a sputtering method, an ion plating method, a plasma chemical vapor deposition method, a thermochemical vapor phase, or the like. There is a method using a chemical vapor deposition method (CVD) such as a growth method or a photochemical vapor deposition method.

  The barrier film, which is a film having the above barrier properties, is superior in transparency and has a high barrier property against oxygen and water vapor as compared with a barrier film using a conventional aluminum foil or the like. This technology is expected not only for food packaging but also for industrial use.

  On the other hand, in recent years, with the background of global warming, environmental pollution, and waste problems due to depletion of resources and an increase in the concentration of carbon dioxide in the atmosphere, the amount of fossil resources used during production is low, and CO2 can be treated with low energy during disposal. The use of environmentally friendly materials that emit less carbon is drawing attention. Under such circumstances, the active use of materials derived from biomass resources that do not use fossil resources as raw materials but that use parts or all of natural plants as raw materials, and biodegradable materials that decompose into water and carbon dioxide in the environment. Expected. The packaging materials are no exception, and the packaging base material is being actively replaced by synthetic materials derived from petroleum resources with papers derived from biomass resources.

  Furthermore, polysaccharide gas barrier coating agents such as water-soluble starch and water-soluble cellulose derivatives have been developed. Since these are naturally derived, it can be said that they are excellent from an environmental and safety standpoint. However, the temperature-humidity dependency of the water-soluble polysaccharide coating material and deterioration of gas barrier properties under high humidity are inevitable.

Various attempts have been made to solve these problems. For example, Patent Document 1 describes gas barrier properties by forming a cellulose nanofiber layer on a substrate, and further describes gas barrier properties improvement by crosslinking with an inorganic compound or metal oxide deposition. However, as a base material, a plastic film such as a cellulose nanofiber that is less likely to affect the base material is examined, and there is no mention of adhesion of the cellulose layer to the base material.
JP 2010-125814 A

  The present invention has been made in consideration of the background art as described above, effectively uses natural resources, does not impair the original function of the base material, has good gas barrier properties, and adheres to the barrier layer. It is an object to provide an excellent sheet material.

As means for solving the above problems, one embodiment of the present invention is a sheet material in which a fine fiber layer containing fine fibers is formed on at least one surface of a base material, and the base material is made of paper. The sheet material is characterized in that the penetration depth of the fine fiber layer into adjacent layers is 0.01 μm or more and 0.02 μm or less .

  The fine fiber layer includes fine fibers (B-1) having a fiber width of 2 nm to 50 nm and a length of the fine fibers of 0.2 μm to 50 μm in the fine fiber layer. .

  Further, the sheet material is characterized in that the fine fiber layer includes fine fibers (B-2) having a fiber width of 50 nm to 200 nm and a length of the fine fibers of 50 μm to 500 μm.

  Moreover, the said fine fiber layer is a sheet | seat material characterized by including both the said fine fiber (B-1) and the said fine fiber (B-2).

  The sheet material is characterized in that the fine fiber layer is formed by coating a fine fiber dispersion containing fine fibers.

  Further, the sheet material is characterized in that the dispersion medium of the fine fiber dispersion contains water.

In addition, when the fine fiber layer is formed by coating a fine fiber dispersion containing fine fibers, the coating amount of the coating is 0.3 g / m ² or more and 15 g / m ² or less in terms of solid weight. It is a characteristic sheet material.

  Moreover, the said fine fiber layer is a sheet | seat material characterized by including a cellulose fiber.

  Further, the sheet material is characterized in that the fine fiber layer formed on at least one surface of the substrate has a thickness of 0.2 μm or more and 10 μm or less.

  Another embodiment of the present invention is a barrier packaging container using a sheet material.

  According to the present invention, it is possible to provide a sheet material that effectively utilizes natural resources, does not impair the original function of the base material, has good gas barrier properties, and is excellent in adhesion of the barrier layer.

It is a schematic sectional drawing of 1st embodiment of the sheet | seat material in this invention. It is a schematic sectional drawing of 2nd embodiment of the sheet material in this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The sheet material in the present invention has a fine fiber layer containing fine fibers formed on at least one surface of the base material, and the base material is formed of any one of paper, woven fabric, non-woven fabric, and porous membrane. is there.

  FIG. 1 is a schematic cross-sectional view of a first embodiment of a sheet material in the present invention. In the sheet material 1 of the present invention, a fine fiber layer 3 containing fine fibers is formed on at least one surface of a base material 2, and the base material 2 is formed of any one of paper, woven fabric, non-woven fabric, and porous membrane. It has been done. Here, as long as the formation of the fine fiber layer 3 is not hindered, any laminate is provided between the base material 2 and the fine fiber layer 3 or on the surface opposite to the surface on which the fine fiber layer 3 is formed. May be formed.

  FIG. 2 is a schematic cross-sectional view of a second embodiment of the sheet material in the present invention. In the sheet material 1 of the present invention, a fine fiber layer 3 containing fine fibers is formed on at least one surface of a substrate 2, and a vapor deposition layer 4 is directly formed on the fine fiber layer 3. Here, a laminate may be formed on the surface of the substrate 2 opposite to the surface on which the fine fiber layer 3 is formed, and any laminate is formed between the substrate 2 and the fine fiber layer 3. Also good. Furthermore, for the purpose of protecting the vapor deposition layer 4 or the like, some laminate may be formed on the surface of the vapor deposition layer opposite to the surface on which the four fine fiber layers 3 are formed.

<Base material>
Although the base material used for this invention is not specifically limited, Paper is preferable from the surface of environmental consideration. Furthermore, it is preferable to use a woven fabric, a non-woven fabric, or a porous membrane because it can be expected to impart various functionalities by having a large specific surface area and possessing pores. That is, by using a base material that is not flat in surface shape such as paper, woven fabric, non-woven fabric, and porous membrane, and that is inherently prone to problems in the manufacturing process such as soaking, wetting, and drying in coating agent coating, The superiority of the present invention is further exhibited. A detailed description of the superiority is given in the section on fine fiber layers.

  In order to improve the formation of the fine fiber layer on the substrate, the substrate may be subjected to a surface treatment to impart wettability and an anchor effect. The surface treatment is not particularly limited, but modifications such as corona discharge treatment, plasma treatment, ultraviolet irradiation, and alkali surface treatment are preferred in view of the gist, cost, and simplicity of the process of the present invention.

  Before and after forming the fine fiber layer, some resin, fine particles, pigment, fragrance, clay, reactive substance, and the like may be contained in the base material.

  For the purpose of imparting a function to the substrate, a metal or the like may be supported. As the metal, platinum, palladium, ruthenium, iridium, rhodium, osmium, platinum group elements, metals such as iron, lead, copper, chromium, cobalt, nickel, manganese, vanadium, molybdenum, gallium, aluminum, or alloys thereof Alternatively, an oxide, a double oxide, a carbide, or the like can be used.

  Alternatively, the base material may contain carbon particles or the like. Carbon particles include all carbon blacks (furnace black, channel black, thermal black, acetylene black, ketjen black, lamp black), fullerenes, carbon nanotubes, carbon nanohorns, carbon nanofibers, and graphite. Any of materials obtained by physically or chemically treating these may be used.

  As the surface roughness of the substrate, the arithmetic average roughness Ra preferably has 2000 nm or less. The base material with a small surface roughness will be described in detail below, but it has little advantage in terms of the sealing effect or smoothness improvement effect of the base material surface by the fine fiber layer, but it has the effect of suppressing gas permeation due to gas barrier properties. Bring. On the other hand, if Ra is larger than 2000 nm, the unevenness on the surface of the substrate cannot be sufficiently filled by forming a fine fiber layer, and gas barrier properties are hardly exhibited.

<Fine fiber layer>
Examples of the raw material of the fine fiber constituting the fine fiber layer used in the present invention include cellulose, chitin, chitosan and the like, and cellulose fiber having a regular structural arrangement and a rigid skeleton is particularly preferable. Wood pulp, non-wood pulp, cotton, bacterial cellulose, and the like can be used as cellulose that is a raw material for cellulose fibers. The method for refining the fine fibers is not particularly limited, and examples thereof include mechanical processing such as high-pressure homogenizer, ultrasonic homogenizer, grinder grinding, freeze grinding, and media mill, and any method may be used. Further, chemical treatment may be performed as a pre-process for performing mechanical treatment. Fine fibers having a desired fiber shape can be obtained by arbitrarily controlling the degree of mechanization or chemical treatment. The chemical treatment will be described later. Moreover, it is preferable that a fine fiber is highly crystalline. High crystallinity improves gas barrier properties, mechanical strength, water resistance and thermal stability.

  As a method for forming the fine fiber layer, a fine fiber dispersion containing fine fibers can be formed by various wet film forming methods, and a known method can be used. Specific examples include a gravure coater, a dip coater, a reverse coater, a wire bar coater, a die coater, and a spray coater. The dispersion medium of the dispersion liquid is not particularly limited, but water is preferable from the viewpoint of working environment and the need for solvent recovery. In addition, an organic solvent such as alcohol may be mixed with the dispersion medium for the purpose of improving the manufacturing process such as coating property and drying property, and improving dispersibility and dispersion stability. Further, the concentration of the dispersion liquid may be arbitrarily adjusted within a range in which there is no problem in forming the fine fiber layer in order to obtain a desired fine fiber layer.

  Regarding the shape of the fine fiber, it is preferable that the fiber width includes 2 nm to 50 nm and the fiber length includes 0.2 μm to 50 μm. That is, in order to maintain a fiber shape, 2 nm or more is preferable, and if it is 50 nm or less, since it has optical transparency, the freedom degree in product design improves. Moreover, if it is 2 nm or more and 50 nm or less, a fiber will be formed into a dense film and a good gas barrier property can be exhibited. Furthermore, if the fiber length is less than 0.2 μm, the fibers are not sufficiently entangled. Particularly when paper, nonwoven fabric, or porous film is used for the base material, the fine fiber is infiltrated into the base material and functions as a film. Yield reduction and film formation itself become difficult. On the other hand, when the thickness is 50 μm or more, the entanglement of the fine fibers becomes too strong, resulting in an increase in viscosity, and a problem is likely to occur in the surface shape of the formed fine fiber layer. Furthermore, the fine fiber soaking impregnates the pores, network structure, etc. of the base material in the fine fiber, resulting in a decrease in the action utilizing this.

  Furthermore, it is preferable that the fiber width includes 50 nm to 200 nm and the fiber length includes 50 μm to 500 μm. By including the fiber having such a shape, the unevenness of the base material can be efficiently filled, and the physical strength of the fine fiber layer is improved, so that cracks and the like are hardly generated. In addition, when the fiber diameter and the fiber length are equal to or more than the upper limit, the surface smoothing due to the increase in viscosity or bulk entanglement tends to occur in the formation of the fine fiber layer. Further, the fine fiber layer includes both fine fibers having a fiber width of 2 nm to 50 nm and a fiber length of 0.2 μm to 50 μm and fine fibers having a fiber width of 50 nm to 200 nm and a fiber length of 50 μm to 500 μm. Is preferable because the effects of gas barrier properties and surface smoothness are further increased. In addition, even if it is a different material which is not a fine fiber having a fiber width of 2 nm to 50 nm and a fiber length of 0.2 μm to 50 μm, or a fine fiber having a fiber width of 50 nm to 200 nm and a fiber length of 50 μm to 500 μm. Of course, the same material is preferable in terms of production efficiency and affinity.

  The shape of the fine fibers can be confirmed by SEM or AFM observation after the fine fiber dispersion prepared to 0.0001 to 0.001 wt% is spread on mica having a smooth surface and dried.

  Further, the fine fiber layer preferably has a crosslinked structure formed by a crosslinking agent from the viewpoint of water resistance. Examples of the crosslinking agent include oxazoline, divinyl sulfone, carbodiimide, dihydrazine, dihydrazide, epichlorohydrin and the like. The said crosslinking agent may be used individually by 1 type, and may use 2 or more types together.

When the fine fiber dispersion containing fine fibers is formed by coating, the coating amount is preferably 0.3 g / m ² or more and 15 g / m ² or less in terms of solid weight. When the coating amount is less than 0.3 g / m ² , particularly when paper, woven fabric, non-woven fabric, or porous membrane is used for the base material, the fine fiber layer cannot be filled following the unevenness of the base material surface. Since the uniform film surface due to the fine fiber layer is hardly formed, the barrier property is lowered. Also, if the coating amount is greater than 15 g / m ² , problems such as cracking are likely to occur in the fine fiber layer and the adjacent substrate or vapor deposition layer accompanying it during handling, and a material for forming the fine fiber layer is necessary. Since the amount increases, an economic problem due to an increase in cost occurs, and the productivity decreases.

  Moreover, it is preferable that the film thickness of the fine fiber layer formed after coating the fine fiber dispersion is 0.2 μm or more and 10 μm or less. When the film thickness is less than 0.2 μm, particularly when paper, woven fabric, non-woven fabric, or a porous film is used as the base material, the effect of covering and smoothing the unevenness on the surface of the base material becomes low. Since the effect of suppressing the generation of pinholes and cracks when forming a dense layer cannot be obtained, the barrier property is lowered. On the other hand, if it is larger than 10 μm, problems such as cracking are likely to occur in the fine fiber layer and the adjacent base material or vapor deposition layer accompanying the handling, and the adhesion decreases due to the difference in the linear expansion coefficient between the fine fiber layer and the base material. Is not preferable because it becomes remarkable.

  Furthermore, it is preferable that the penetration depth to the adjacent layer of the fine fiber layer is 0.01 μm or more and 1.5 μm or less. If it is larger than 0.01 μm, the physical anchor effect is exhibited, so that the adhesion is good. On the other hand, the infiltrated fine fibers cannot form a dense film and cannot function as a barrier layer. If the penetration depth is 1.5 μm, the necessary amount of the material for forming the fine fiber layer can be suppressed, and the functions inherent to the base materials such as paper, woven fabric, nonwoven fabric and porous membrane are inhibited. Thus, the barrier layer can be formed without doing so.

<Deposition layer>
In the present invention, the vapor deposition layer can be formed on the side of the substrate on which the fine fiber layer is formed by electron beam heating vacuum deposition. The vapor deposition method for forming the vapor deposition layer used in the present invention may be a physical vapor deposition method (PVD) such as a vacuum film formation method, a sputtering method, an ion plating method, a plasma chemical vapor deposition method, or a thermal chemical vapor deposition method. And chemical vapor deposition (CVD) such as photochemical vapor deposition, etc., and by using these vacuum processes, a metal oxide deposited layer such as silicon oxide or aluminum oxide may be used. it can.
Although the preferable film thickness of a vapor deposition layer changes according to the use of the said barrier film, the film | membrane composition of a vapor deposition film, etc., the range of several tens to 5000 mm is preferable normally. If this deposited layer is thinner than several tens of inches, the continuity of the deposited layer is not maintained, and if it is thicker than 5000 inches, cracks are likely to occur.
Note that, as a pre-process for forming the vapor deposition layer, plasma treatment or the like may be performed to remove moisture, dust or the like on the surface of the fine fiber layer, and promote smoothing and activation of the surface.

  As described above, a sheet material in which a fine fiber layer containing fine fibers is formed on at least one surface of a base material, and the base material is composed of any one of paper, woven fabric, non-woven fabric, and porous membrane is used. Thus, it is possible to produce a gas barrier packaging container that has good gas barrier properties and can utilize the original function of the substrate.

[Chemical treatment of fine fibers]
Next, the fine fibers used in the present invention are subjected to chemical treatment, and further subjected to subsequent mechanical treatment, whereby fine fibers having a desired shape can be obtained with low energy. An example of chemical treatment of cellulose as a fiber is shown below.

As a method of chemically treating cellulose, 2,2,6,6-tetramethyl-1-pipedinyloxy radical (TEMPO) is used as a catalyst, and an oxidizing agent such as sodium hypochlorite while adjusting pH, A treatment method using bromide such as sodium bromide has been proposed. When the hydroxyl group at the C6-position of cellulose is carboxylated by this method, the electrostatic repulsion between cellulose fibers increases and swells. Therefore, cellulose is converted into nanofibers by mechanical treatment with low energy input, and an aqueous dispersion of cellulose is obtained. Furthermore, when the present method is used, the molecular weight reduction of the obtained cellulose nanofiber is suppressed, so that the fine fiber layer has high mechanical strength.

The chemical treatment described above is performed according to the following procedure.
Nitroxyl radical and sodium bromide are added to cellulose dispersed in water, and sodium hypochlorite aqueous solution is added with stirring at room temperature to oxidize the cellulose. Sodium hydroxide is added during the oxidation reaction to control the pH in the reaction system to 10.5. At this time, the hydroxyl group at the C6 position on the surface of the cellulose fiber is oxidized to a carboxyl group. What was sufficiently washed with water and refined the obtained cellulose can be used as a constituent material of the fine fiber layer.

  In addition, as an oxidizing agent, hypohalous acid or its salt, a halogenous acid or its salt can be used, and sodium hypochlorite is preferable. Examples of the bromide include lithium bromide, potassium bromide, sodium bromide and the like, and sodium bromide is preferable.

  Cellulose nanofibers used for the fine fiber layer have a carboxyl group content of 0.1 to 3.0 mmol / g, preferably 1.0 mmol / g or more based on the weight of cellulose by chemical treatment. The cellulose after chemical treatment obtained in this way is easy to proceed with fiber refinement by mechanical treatment in water, and a homogeneous dispersion can be obtained, so that a uniform film thickness and a uniform layer can be formed on the substrate. Become. Further, as the miniaturization progresses, the fiber diameter of the cellulose nanofiber becomes on the order of several nanometers, and it is considered that this thin fiber diameter forms a dense film as a fine fiber layer and exhibits high barrier properties.

  In addition, the amount of carboxyl groups contained in cellulose is calculated by the following method. 0.2 g of dry weight conversion of chemically treated cellulose is taken in a beaker, and 80 ml of ion exchange water is added. Thereto was added 5 ml of a 0.01 M sodium chloride aqueous solution, and 0.1 M hydrochloric acid was added while stirring to adjust the whole to pH 2.0. Here, 0.1M sodium hydroxide aqueous solution was injected at 0.05 ml / 30 seconds using an automatic titrator (AUT-701, manufactured by Toa DKK Co., Ltd.), and the conductivity and pH value were measured every 30 seconds. The measurement was continued until pH 11. A titration amount of sodium hydroxide was determined from the obtained conductivity curve, and the carboxyl group content was calculated.

  The production of the sheet material having gas barrier properties of the present invention will be described below. However, the present invention is not limited to the following examples.

The materials used in this example are shown below.
<Substrate: A>
Paper was used as the substrate used in this example. In addition, a commercially available PET film was used as a comparative material.
Base material A-1: Commercially available high-quality paper (basis weight 64 g / m ² )
Base material A-2: PET film (Toray, Lumirror, thickness 25 μm)

<Fine fiber layer: B>
Cellulose nanofibers were used as the fine fibers used in this example. In addition, cellouronic acid was used as a comparative material.
Fine fiber B-1: Cellulose nanofibers having an average fiber width of 4 nm and an average fiber length of 1.0 μm (solid content concentration 2% by mass)
Fine fiber B-2: Cellulose nanofibers having an average fiber width of 150 nm and an average fiber length of 100 μm (solid content concentration: 2% by mass)
Fine fiber B-3: Cellouronic acid (solid content concentration 10% by mass)
Cellulose nanofibers, which are constituent materials of the fine fiber layer, were obtained by the following method.

(1) Reagent / Material-1
Cellulose: Bleached kraft pulp (Fletcher Challenge Canada, Machenzie),
TEMPO: Commercial product (Tokyo Chemical Industry Co., Ltd., 98%),
Sodium hypochlorite: a commercial product (Wako Pure Chemical Industries, Ltd., Cl: 5%),
Sodium bromide: Commercial product (Wako Pure Chemical Industries, Ltd.)

(2) TEMPO oxidation reaction of cellulose-1
In a 2 L glass beaker, bleached kraft pulp having a dry mass of 10 g and 500 ml of ion-exchanged water were placed and allowed to stand overnight to swell the pulp. The temperature was adjusted to 40.0 ° C. with a water bath with temperature control, and 0.1 g of TEMPO and 1 g of sodium bromide were added and stirred to obtain a pulp suspension. Furthermore, 5 mmol / g sodium hypochlorite per cellulose mass was added with stirring. At this time, about 1 M aqueous sodium hydroxide solution was added to maintain the pH of the pulp suspension at about 10.5. Thereafter, the reaction was performed for 120 minutes, and the pulp was sufficiently washed with ion-exchanged water to obtain TEMPO oxidized cellulose.

(3) Dispersion treatment of TEMPO oxidized cellulose-1
The obtained TEMPO-oxidized cellulose is adjusted to a predetermined concentration in ion-exchanged water, stirred for 30 minutes using a mixer (Osaka Chemical, Absolute Mill, 14,000 rpm), and refined to make transparent cellulose nanofibers An aqueous dispersion (solid content concentration 2 mass%) was obtained (fine fiber B-1). Similarly, what was stirred for 2 minutes at 7000 rpm for the dispersion condition of the mixer was designated as fine fiber B-2. When the fine fibers B-1 and B-2 were diluted to a solid content concentration of 0.0001% by mass, developed on mica in small amounts, dried and observed with AFM, the average fiber width and fiber length of 10 fibers were respectively B-1. : 4 nm, 1.0 μm, B-2: 150 nm, 80 μm.

  Furthermore, with reference to Japanese Patent No. 4848891, cellouronic acid, which is a comparative material for the fine fiber layer, was obtained by the following method.

(4) Reagent / Material-2
Cellulose: Regenerated cellulose (manufactured by Asahi Kasei Kogyo Co., Ltd., Benrize),
TEMPO: Commercial product (Tokyo Chemical Industry Co., Ltd., 98%),
Sodium hypochlorite: commercially available product (manufactured by Wako Pure Chemical Industries, Ltd., Cl: 5%),
Sodium bromide: Commercial product (Wako Pure Chemical Industries, Ltd.)

(5) TEMPO oxidation reaction-1 of regenerated cellulose
In a 2 L glass beaker, 10 g of regenerated cellulose and 500 ml of ion-exchanged water were added to form a suspension. The temperature was adjusted and cooled to 5 ° C., and 0.1 g of TEMPO and 1 g of sodium bromide were added and stirred. Furthermore, 5 mmol / g sodium hypochlorite per cellulose mass was added with stirring. At this time, about 1 M aqueous sodium hydroxide solution was added to maintain the pH of the pulp suspension at about 10.5. 120 minutes after the start of the reaction, the regenerated cellulose was completely dissolved. Here, ethanol was added to stop the reaction, and the reaction solution was poured into ethanol to precipitate the product, which was sufficiently washed with a solution of water: acetone = 1: 7, and then treated with seurouronic acid (B-3). Got. The weight average molecular weight of polyuronic acid was 25,000.

Example 1
The base fiber A-1 is coated with an aqueous dispersion of fine fibers B-1 with a coater bar, and dried at 120 ° C. for 20 minutes in a drying furnace, thereby obtaining a fine weight of 1.5 g / m ^{2 in} terms of solid content. A fiber layer was formed to obtain a sheet material.

(Example 2)
An aqueous dispersion was prepared so that the solid weights of the fine fibers B-1 and B-2 were equal, and applied to the substrate A-1, and a sheet material was obtained in the same manner as in Example 1.

(Comparative Example 1 and Comparative Example 2)
By adjusting the solid content concentration of the fine fiber B-3 in the same manner as in Example 1 except that the fine fiber B-3 was used for the fine fiber layer, 1.5 g / m ² and 5.0 g / m. ² sheet material was obtained.

(Example 3)
After applying the adhesive of the sheet material produced in Example 1, LLDPE having a thickness of 30 μm was dry-laminated to obtain a sheet material having LLDPE laminated on both surfaces.

(Comparative Example 3)
A sheet material was produced in the same manner as in Example 1 except that the substrate A-2 was used, and a sheet material on which LLDPE was laminated was obtained in the same manner as in Example 3.

(Comparative Example 4)
A sheet material was obtained in the same manner as in Comparative Example 3 except that the fine fiber B-3 was used in Comparative Example 3.

[Evaluation]
About each sheet material obtained in Examples 1-2 and Comparative Examples 1-2, oxygen permeability and water vapor permeability were measured. Furthermore, adhesion strength evaluation was performed in Example 3 and Comparative Examples 3-4.

<Coating amount>
The coating amount of the fine fiber layer was calculated by cutting a base material on which the sheet material and the fine fiber layer were not formed into a 15 cm square and dividing the weight difference by the cut area.
<Film thickness>
The sheet material on which the fine fiber layer was formed was cut out and included in a resin, and a cross section was obtained in the direction perpendicular to the sheet surface with a microtome and observed with an SEM. The thickness of the film laminated on the fine fiber layer side from the substrate surface was measured.
<Penetration depth>
The sheet material on which the fine fiber layer was formed was cut out and included in a cut resin, and a cross-section taken out in the direction perpendicular to the sheet surface with a microtome was observed with microscopic FT-IR. The depth from the surface of the base material into which the fine fibers penetrated into the base material was evaluated.
<Oxygen permeability>
In Examples 1-2 and Comparative Examples 1-2, the oxygen permeability was measured using an oxygen permeability measuring apparatus (Modern Control, OXTRAN 10 / 50A) in an atmosphere of 30 ° C. and 40% RH. Moreover, in Example 3 and Comparative Examples 3 to 4, a sheet material in which LLDPE was laminated as shown below was measured.
<Water vapor permeability>
In Examples 1-2 and Comparative Examples 1-2, after forming a vapor deposition layer by the following method, the water vapor transmission rate is 40 ° C. and 90% RH atmosphere using a water vapor transmission rate measuring device (Modern Control, PERMATRAN W6). Measured below.
<Deposition>
Using an electron beam heating type vacuum deposition apparatus (Canon Optron, SiO), silicon oxide is evaporated by heating, and a SiOx film having a cured film thickness of 50 nm at a pressure of 1.5 × 10 ⁻² Pa during film formation. Formed.
<Adhesion strength>
The sheet material on which LLDPE was laminated was cut into strips of 15 mm × 150 mm. Further, a trigger was made so that the interface between the substrate and the fine fiber layer appeared, and both sides of the LLDPE were pulled at 200 mm / min to perform T-peeling, and the adhesion strength was measured.

  The evaluation results of oxygen permeability, water vapor permeability, and adhesion strength are shown in Tables 1-2. As shown in Table 1, it was found that by using the fine fibers of Examples 1 and 2, good oxygen barrier properties and water vapor barrier properties can be obtained while suppressing the penetration of fine fibers into the substrate. Further, as shown in Table 2, it was found that even when the base material is paper with low surface smoothness, the oxygen barrier property is good and a high adhesion strength can be obtained.

According to the present invention, it is possible to provide a sheet material that effectively utilizes natural resources, does not impair the original function of the base material, has good gas barrier properties, and is excellent in adhesion of the barrier layer. Furthermore, a barrier packaging container using the same can be produced. Since materials with a large specific surface area, such as paper, woven fabric, nonwoven fabric, and porous membrane, can be used without sacrificing the original function of the material, it can be used only in the packaging field of food, pharmaceuticals, daily necessities, etc. It can be suitably used as a gas barrier packaging material in a wide range of fields such as electronic members.

1: Sheet material 2: Base material 3: Fine fiber layer 4: Deposition layer

Claims (10)

A sheet material in which a fine fiber layer containing fine fibers is formed on at least one surface of the substrate,
The substrate is made of paper;
A sheet material, wherein a penetration depth into an adjacent layer of the fine fiber layer is 0.01 μm or more and 0.02 μm or less .   It is a sheet material of Claim 1, Comprising: The fine fiber (B-1) whose fiber width of the said fine fiber is 2 nm or more and 50 nm or less and whose length of a fine fiber is 0.2 micrometer or more and 50 micrometers or less is included in a fine fiber layer. A sheet material characterized by that.   3. The sheet material according to claim 1, wherein the fine fiber includes a fine fiber (B-2) having a fiber width of 50 nm to 200 nm and a fine fiber length of 50 μm to 500 μm. A sheet material characterized by that.   The sheet material according to claim 1, wherein the fine fiber layer includes both the fine fiber (B-1) and the fine fiber (B-2).   The sheet material according to any one of claims 1 to 4, wherein the fine fiber layer is formed by coating a fine fiber dispersion containing fine fibers.   The sheet material according to claim 5, wherein a dispersion medium of the fine fiber dispersion contains water. The sheet material according to claim 5 or 6, wherein when the fine fiber layer is formed by coating a fine fiber dispersion containing fine fibers, the coating amount of the coating is 0.3 g / m in terms of solid weight. ^{2 to} 15 g / m ² or less.   The sheet material according to any one of claims 1 to 7, wherein the fine fiber layer contains cellulose fibers.   It is a sheet | seat material of any one of Claims 1 thru | or 8, The film thickness of the fine fiber layer formed in the at least one surface of the said base material is 0.2 micrometer or more and 10 micrometers or less, It is characterized by the above-mentioned. Sheet material. A barrier packaging container using the sheet material according to any one of claims 1 to 9 .

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