JP2003154609A - Recyclable transparent barrier laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recyclable transparent barrier laminate having both of high oxygen barrier properties and moistureproof properties and easy in the regeneration of used papers after use. SOLUTION: The recyclable transparent barrier laminate is constituted by successively laminating an oxygen barrier layer and a heat seal layer on at least one surface of a paper support, and the value of moisture permeability due to a JIS-Z0208-B method of the laminate is set to 50 g/m<2> .24h.atm or less, the value of oxygen permeability due to a JIS-K7126-B method thereof is set to 100 cc/m<2> .24h.atm or less and the value of opacity thereof due to a JIS-P8138 method is set to 40% or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a recyclable transparent material suitable for various flexible packaging materials, particularly individual packaging such as cigarettes and confectionery, or overwrapping (integrated packaging) of already packaged products. The present invention relates to a barrier laminate.

[0002]

2. Description of the Related Art Generally, for individual packaging of confectionery such as gum and chocolate, tobacco, etc., or integrated packaging,
From the viewpoints of transparency, gas barrier properties, moisture resistance, and aroma retention properties, various gas barrier resins represented by polyvinylidene chloride (PVDC) or ethylene-vinyl alcohol (EVOH) copolymer compositions are used. , Coated with or laminated on a base material such as a polyolefin film or a polyester film, or a composite of these as a co-extrusion film, or a laminate of these films is used. .

Above all, polyvinyl alcohol, ethylene-vinyl alcohol copolymer and the like show an extremely high oxygen barrier property due to a strong intermolecular cohesive force due to a hydrogen bond and, in addition, do not contain chlorine like PVDC and are therefore environmentally friendly. In recent years, it has been drawing attention as the most suitable base material for packaging materials that require general-purpose barrier properties. However, in these oxygen-barrier resins having hydrogen bonding properties, when placed in a high-humidity environment, moisture is adsorbed by hydrophilic groups in the resin and the intermolecular cohesive force is weakened, resulting in a significant decrease in oxygen barrier properties. There is also the drawback that it will end up.

Therefore, when these hydrogen-bonding resins are used as a packaging material, generally, a substrate having a low water vapor permeability, for example, a polyolefin film such as polypropylene or polyethylene, or a physical or chemical surface thereof is used. A method of reducing the partial pressure of water vapor on the surface of the hydrogen-bonding resin and reducing the influence of humidity by taking a multilayer with a film that has been subjected to a mechanical treatment (metal vapor deposition, CVD, etc.) has been adopted.

As a packaging material to which the oxygen-barrier resin having such a problem is successfully applied, for example, a paper support,
Multilayer gas barrier film (Japanese Patent Publication No. 52-24948) in which an ethylene-vinyl acetate copolymer saponified product, an ethylene-vinyl acetate copolymer partially saponified product, and a polyolefin-based resin film are laminated in this order, synthetic resin film / ethylene-acetic acid One in which a saponified vinyl copolymer / polyolefin film is laminated in this order, and an adhesive layer containing a water-absorbent resin is provided between the layers (Japanese Patent Laid-Open No. 63-120643).
Japanese Patent Laid-Open Publication No. 4), an oxidation catalyst such as a transition metal compound is added to a saponified product of ethylene-vinyl acetate copolymer, and the mixture is mixed with a polyolefin resin or the like and melt-injection-molded (Japanese Patent Application Laid-Open No. Hei 4-
No. 211444) and the like are disclosed in large numbers.

However, such a barrier substrate is
Most of them are laminated structures with plastic films, and most of them are melt injection molded as a mixture of them.
Even when a vinyl alcohol resin or the like is used alone, the oxygen barrier property in a high humidity environment has not yet reached a satisfactory level.

Furthermore, in recent years, as environmental problems on a global scale have become more serious, the treatment of packaging waste has been taken up as a social problem, and the industry is now under pressure to deal with it. Although the packaging materials as described above are all excellent in moisture proofness / oxygen barrier property, no consideration was given to their own recyclability.
Against the background of such social trends, there is still a strong demand for the promotion of research and development for transparent packaging materials that have excellent oxygen barrier properties and moisture resistance and can be recycled as waste paper.

[0008]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to have a high oxygen barrier property and a moisture proof property, and to have excellent visibility of the object to be packaged. It is to provide a barrier laminate.

[0009]

In view of the present situation, the present inventors have made earnest studies on a recyclable transparent barrier substrate having both high oxygen barrier property and moisture proof property, and as a result, have the following constitutions. It was found that the above problems can be solved by the above.

That is, the first aspect of the present invention is a laminated body in which an oxygen barrier layer and a heat seal layer are sequentially laminated on at least one surface of a paper support, and the laminated body according to JIS-K7126-. Value of oxygen permeability by method B is 1
00cc ^/ m 2 ^/ 24h ^/ atm or less, JIS-Z02
The water vapor transmission rate according to the 08-B method is 50 g / m ² · 24h ·
It is a recyclable transparent barrier laminate having an atm value of not more than atm and an opacity value of not more than 40% according to JIS-P8138.

In a second aspect of the present invention, the paper support is a transparent paper whose main raw material is pulp fibers beaten to a pulp freeness of 100 ml CSF or less, and the water content of the paper support is 3 to 30%. It is a recyclable transparent barrier laminate using transparent paper calendered with a roller having a surface temperature of 80 ° C. or higher as a paper support.

A third aspect of the present invention is that the oxygen barrier layer has an ethylene content of 55 mol% or less and a saponification degree of 9%.
A recyclable transparent barrier laminate comprising at least one saponified ethylene-vinyl acetate copolymer having a saponification degree of 90% or polyvinyl alcohol having a saponification degree of 90% or more.

A fourth aspect of the present invention is a recyclable transparent barrier laminate in which the heat seal layer is composed of a mixed resin composition of a thermoplastic resin and a wax.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The transparent barrier laminate according to the present invention is designed so that when it is used as a packaging material, the article to be packaged can be visually recognized.
The opacity value according to IS-P8138 is preferably 40% or less, and more preferably 20% or less in order to obtain better visibility. When the opacity exceeds 40%, it is difficult to see the printed display or the appearance of the packaged object, and thus it is unsuitable as a packaging material which is required to have transparency.

In addition, the antioxidation or aroma retention of the packaged item
The JIS of the transparent oxygen barrier laminate for the purpose of maintaining
-Oxygen permeability value by K7126-B method is 100 cc
/ M ^Two・ 24h ・ atm or less is preferable.
PV used as a general oxygen barrier material
20 to obtain the oxygen barrier property of DC coated product level
cc / m^Two・ 24h ・ atm or less is preferable
Yes. In addition, for the purpose of protecting the packaged item from moisture, or
Deterioration of oxygen barrier properties of the oxygen barrier layer due to humidity
For the purpose of prevention, the transparent oxygen barrier laminate JIS
-The value of the water vapor transmission rate by the Z0208-B method is 50 g / m.^Two・
24h ・ atm or less, further 40g / m^Two・ 24h ・
It is preferably atm or less.

In the present invention, the support is what is called transparent paper, and generally includes glassine paper, resin-impregnated paper, condenser paper, tracing paper and the like. As a method for obtaining these transparent papers, for example, Japanese Patent Publication No. 45-38729 and Japanese Patent Publication No. 46-157.
No. 23, etc., a method in which pulp fibers and sheets are air-excluded as much as possible by making cellulose fibers highly beaten to bring the fibers into close contact with each other, and JP-B-59-
As disclosed in Japanese Patent Publication No. 7840 and Japanese Patent Publication No. 8-188980, a method of mixing paper with a substance for filling voids in the fiber such as a polymer material or fine fiberized pulp, or papermaking, is disclosed in Japanese Patent Publication No. 51-27662. JP-A-52-189
There is known a method in which paper is produced by a usual method and then treated with a transparentizing agent such as starch, liquid paraffin, a plasticizer, and a polymer material, as disclosed in JP-A-14.

The paper support particularly preferably used in the present invention is a transparent paper such as glassine paper made from pulp fibers beaten to a pulp freeness of 100 ml CSF or less, preferably 50 ml CSF or less, and has a water content of paper. A transparent paper calendered with a roll having a surface temperature of 80 ° C. or higher, preferably 120 ° C. or higher at 5 to 30%, preferably 8 to 20%. When the pulp freeness is higher than 100 ml CSF, the transparency is lowered, which is not preferable. Also calendar
Under the treatment conditions, if the water content of the paper is 5% or less, the transparency becomes low, and conversely, if the water content is higher than 30%, it is not preferable because the transparency unevenness or pulp fibers are taken off to the calender rolls.

The transparent paper may be impregnated or coated with a general clarifying agent for the purpose of further improving transparency and improving dimensional stability against humidity. Examples of the clarifying agent include petroleum-based hydrocarbon resins, rosin-based resins, acrylic-based resins, polyester-based resins, urethane resins, nitrite cellulose-based resins, and the like. In particular, a resin composition having a property that the refractive index of the coating is close to that of cellulose (about 1.5) is preferably used.

Further, the transparent paper used in the present invention is a J.TAPPI-N for the purpose of preventing the oxygen barrier resin applied as the first layer from seeping into the base paper.
o. The value of oil repellency in No. 41 (kit method) is 7 or more, and when the oxygen barrier layer is formed with a lower coating amount, it is preferably 10 or more. When the oil repellency is 7 or less, in order to obtain an effective film thickness as an oxygen barrier layer,
It is not preferable because a large amount of coating liquid is required.

In the present invention, the transparent paper has a basis weight of 10 to 10.
100 g / ^{m 2,} preferably 20~45g / ^{m 2.} When the basis weight is less than 10 g / m ^{2, the} dimensional stability due to strength and load is poor, tension control during processing becomes difficult, wrinkles are likely to occur, and there is a risk of loss during handling. On the other hand, if it exceeds 100 g / m ² , problems such as poor processability as a packaging material and deterioration of transparency occur.

Examples of the raw material of the pulp fiber used in the present invention include softwood, hardwood bleached chemical pulp, cotton, linter, waste paper pulp, mechanical pulp and the like obtained by the kraft method and the sulfite method. Then, any of these pulp fibers is used alone or in any mixing ratio. For beating these pulp fibers, a commonly used beating machine such as a disc refiner, a conical refiner, or a cylindrical refiner can be used.

Further, when making these transparent papers, commonly used paper-making aids such as sizing agents, paper-strengthening agents, sulfuric acid bands, and drainage improving agents are appropriately used.

In the present invention, an oxygen barrier layer is provided as a first layer on at least one surface of the transparent paper support. In the present invention, these oxygen barrier layers can be obtained by coating / drying an oxygen barrier resin having a strong hydrogen bonding property on a paper support. Oxygen-barrier resin having such hydrogen bonding property is more likely to promote crystallization of the film in the drying step after coating and is less likely to cause pinholes, etc. It is possible to obtain a high oxygen barrier property with a thinner film thickness, and because it is a thin film layer, disaggregation after disposal is also possible.

Examples of the oxygen barrier resin preferably used in the present invention include polyvinyl alcohol, saponified ethylene-vinyl acetate copolymer, polyalcohol (reduction product of polyketone), polyvinylpyrrolidone, polyacrylic acid and the like. Examples thereof include so-called polysaccharides such as esters, polyacrylonitrile, or starch and modified products thereof, cellulose and modified products thereof, dextran, chitosan, mannan, etc. Among them, polyvinyl alcohol having a saponification degree of 90% or more is particularly preferable. Or a saponified ethylene-vinyl acetate copolymer having a saponification degree of 90% or more and an ethylene content of 55 mol% or less. In this case, when the saponification degree of polyvinyl alcohol or the saponified product of ethylene-vinyl acetate copolymer is 90% or less, or when the ethylene content of the saponified product of ethylene-vinyl acetate copolymer is 55 mol% or more, drying occurs. The intermolecular cohesive force of the coating is reduced,
It is not preferable because sufficient oxygen barrier property may not be obtained.

The oxygen-barrier resin is preferably liquid, and in the present invention, the aqueous solution thereof is polyvinyl alcohol, and the saponified ethylene-vinyl acetate copolymer is water / propyl alcohol. A solution prepared by dissolving a known saponification product of an ethylene-vinyl acetate copolymer such as water or water / butyl alcohol is used.

Further, in the present invention, the oxygen barrier property can be further improved by using an inorganic layered compound having flatness and a cross-linking agent together with the oxygen barrier layer. This is because oxygen gas cannot pass in the thickness direction from the plane direction of the inorganic layered compound, so by spreading these inorganic layered compounds in the oxygen barrier layer in the scale of fish, it is intended to prevent the passage thereof. . In addition, at the same time, by blending these inorganic layered compounds, the continuity of the oxygen barrier resin film forming the oxygen barrier layer is reduced, so that the disintegration property of the substrate is significantly improved.

Examples of the inorganic layered compound include clay minerals such as kaolinite group, antigorite group, smectite group and mica group. Among them, smectite group such as montmorillonite, saponite and hectorite are used. preferable. The particle size of the inorganic layered compound used is preferably in the range of 10 nm to 5 μm, and more preferably 1 μm or less from the viewpoint of transparency of the substrate.

As the cross-linking agent, hydrogen bondability is improved for the purpose of improving the water resistance of these oxygen-barrier resins and further improving the oxygen-barrier properties by eliminating the interface between the inorganic layered compound and the oxygen-barrier resin. It is preferable to use a crosslinking agent for the base. Examples of such cross-linking agents include titanium-based coupling agents, silane-based coupling agents, epoxy-based coupling agents, and zirconia compounds.

In the present invention, a heat seal layer is further provided as a second layer on the oxygen barrier layer. In the present invention, this heat-sealing layer has not only the original heat-sealing performance but also moisture-proof performance for the purpose of protecting the oxygen barrier layer from moisture. Therefore, the heat-sealing layer in the present invention is composed of a mixed composition of thermoplastic resin and wax.

The thermoplastic resin used in the present invention is, for example, a styrene-butadiene copolymer, an acrylic-styrene copolymer, a methacrylate-butadiene copolymer, an acrylic copolymer, a polyester copolymer. ,
Polyurethane-based copolymers and the like can be mentioned, but in view of transparency after coating, heat sealability, and disintegration property, acrylic-styrene-based copolymers and acrylic-based copolymers are particularly preferable in the present invention. used.

Examples of such acrylic resins include methyl acrylate, ethyl acrylate, acrylic acid n
-Butyl, isobutyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, 2-acrylate
Acrylic acid ester such as hydroxyethyl as a main component, and other compounds copolymerizable with them, such as methacrylic acid ester, unsaturated carboxylic acid, (meth) acrylamide compound, aromatic vinyl compound, conjugated diene compound, etc. The thing which polymerized the monomer etc. is mentioned.

The preferred glass transition temperature (Tg) of the thermoplastic resin used in the present invention is within the range of 30 ° C to 100 ° C. If the Tg of the thermoplastic resin is less than 30 ° C., the surface of the heat seal layer is blocked, which is not desirable, and if the Tg is more than 100 ° C., a sufficient film cannot be formed, resulting in problems such as clouding of the coating layer and film cracking. Is not desirable.

Examples of the wax used in the present invention include paraffin wax, microcrystalline wax, polyethylene wax, carnauba wax,
Examples include montan wax and candelilla wax. Among these, paraffin wax, which has particularly high crystallinity and excellent moisture resistance, is preferable.

The compounding ratio of the wax component is, in terms of solid content, thermoplastic resin 99.5-80: wax 0.5-2.
It is preferably in the range of 0, and more preferably in the range of thermoplastic resin 99 to 90: wax 1 to 10.
If the blending ratio of the wax is less than 0.5, sufficient moistureproof performance cannot be obtained, and if it is 20 or more, not only sufficient heat sealing performance cannot be obtained, but also the transparency of the heat sealing layer may be impaired. Therefore, it is not preferable.

In addition, various additives such as a plasticizer, an antiblocking agent, an ultraviolet absorber, a dye and an antifoaming agent may be added to the heat seal layer in the present invention.

In the present invention, an oxygen barrier layer as described above,
The heat-sealing layer can be obtained by sequentially applying the resin composition that constitutes the heat-sealing layer on a transparent paper substrate and drying the resin composition.
Examples of the coating method of these resin compositions include roll coating, size press coating, air knife coating, gravure coating, blade coating, die coating, and bar coating, but these methods are not always required. It is not limited.

The coating amount of the oxygen barrier layer and the heat seal layer to be provided is preferably 0.1 g / m ² to 10 /.
m ² range, and more preferably 0.5 g / m ² ~
It is in the range of 8 g / m ² . The coating amount is 0.1 g / m ²
If it is less than 10 g, the expected oxygen barrier performance or heat seal performance is not obtained, and if it exceeds 10 g / m ² , on the contrary, not only the respective performance reaches the ceiling,
It is economically disadvantageous, and there is a risk that transparency may be deteriorated and blocking may occur.

In the present invention, the oxygen barrier layer and the heat seal layer can be provided on either one side or both sides of the paper support. Especially, when a one side coated product is used as a packaging material. In order to minimize the deterioration of the oxygen barrier property due to humidity, it is preferable to use the paper support with the non-coated surface inside (the side of the object to be packaged).

[0039]

[Examples] The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, "%" means "mass%". <Example 1> As a paper support, pulp freeness of 50 m
The pulp sheet beaten to 1 CSF is made into paper and the water content is 20
% And a roll temperature of 130 ° C. were used for calendering to obtain a transparent paper having a basis weight of 30.5 g / m ² and an opacity of 20%. Next, in 50% by mass of a solvent prepared by mixing water / 2-propanol at a mixing ratio of 1: 1, an ethylene-vinyl acetate copolymer saponified product (trademark: Soanol D16, solid content 16%, saponification degree 90% or more) , Ethylene content 29 mol%, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 50% by mass were added, and the mixture was stirred while maintaining the coating temperature at 50 ° C. to obtain an oxygen barrier coating. The obtained oxygen-barrier coating was hand-coated on one side of the glassine paper with a Meyer bar at a solid content of 4 g / m ² and then coated / dried with a blow dryer at 120 ° C. to obtain oxygen. A barrier layer was provided.

Separately from this, 76% by mass of acrylic styrene resin (trademark: LA812F6, solid content concentration 25%, manufactured by Clariant Polymer Co., Ltd.), and paraffin wax (trademark: H-620, solid content concentration 32%, Chukyo Yushi Co., Ltd.) 3% by mass, and MMA beads (trademark: M) dispersed in pure water with a homomixer so that the solid content concentration is 1%.
X180, particle diameter 1.8 μm, Soken Chemical Co., Ltd.) 21% by mass were mixed and stirred to obtain a heat-sealable coating material. 4 g / m ^{2 of the} obtained heat-sealable coating material on the oxygen barrier layer in terms of solid content using a Meyer bar.
After hand coating, coating / drying was carried out with a blow dryer at 120 ° C. to provide a heat seal layer to obtain a target transparent barrier laminate. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

(Evaluation method of moisture permeability) JIS-Z0208
According to the -B method (cup method), the sample coated surface was set to the outside and the moisture permeability was measured. (Evaluation method of oxygen permeability) According to JIS-K7123-B method (isobaric method), the sample coated surface is set on the oxygen detection side, and the oxygen permeability is measured under dry conditions (23 ° C, 0% RH). It was

(Evaluation Method of Opacity) JIS-P813
According to 8, the opacity of the sample was measured. (Evaluation method of disintegration property) About 8 g of a sample piece cut into a 3 cm square was stirred with 500 ml of water for 90 seconds with a household mixer (the mixer blade was scraped off with a file so as not to cut the pulp fiber). did. The obtained slurry was applied to a flat screen (10 cuts), and the rejected portion was slurried with a pulp concentration of 1.5%.
After the readjustment, a hand-made sheet having a basis weight of 50 g / m ² was prepared by a laboratory square sheet machine equipped with a 150-mesh wire mesh. The obtained hand-made sheet is visually evaluated, and contains undisintegrated matter, or × when it is impossible to disintegrate,
When almost no undisintegrated matter was contained, it was marked as ○.

<Example 2> As an oxygen barrier coating, a polyvinyl alcohol aqueous solution (trademark: PVA117, saponification degree of 98% or more, manufactured by Kuraray Co., Ltd.) prepared to have a solid content of 5% was used. A transparent barrier laminate was obtained in the same manner as in Example 1. Using the obtained sample,
The oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Example 3> As an oxygen barrier coating, 50% by mass of a polyvinyl alcohol aqueous solution (trademark: PVA117, saponification degree of 98% or more, manufactured by Kuraray Co., Ltd.) prepared with a solid content of 5%, and a solid content A mixture of 50% by mass of synthetic smectite (trademark: Lucentite SWN, particle size 30 to 50 nm, manufactured by Coop Chemical Co.) dispersed in pure water with a homomixer to a concentration of 2% was used. A transparent barrier laminate was obtained in the same manner as in Example 1 except for the above. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Example 4> As a paper support, an acrylic styrene resin (trademark: Polymalon 356-25, solid content concentration 25) was prepared on both sides of a transparent paper obtained in the same manner as in Example 1.
%, Manufactured by Arakawa Chemical Co., Ltd.) with a Mayer bar to a solid content of 2 g / m ² respectively, and then 12
Coating / drying was performed with a blower dryer at 0 ° C to obtain a basis weight of 34.
A transparent barrier laminate was obtained in the same manner as in Example 1 except that transparent paper having 5 g / m ² and an opacity of 15% was used. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Comparative Example 1> As a paper support, a pulp sheet beaten to a pulp freeness of 350 ml CSF was made into a paper, calendered under the conditions of a water content of 6% and a roll temperature of 50 ° C., and a basis weight of 50 g / m 2. ² , opacity 65
% Transparent wood laminate was obtained in the same manner as in Example 1 except that high-quality paper was used. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Comparative Example 2> As a paper support, the thickness is 30 μm.
A transparent barrier laminate was obtained in the same manner as in Example 1 except that the PET film of m was used. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

Comparative Example 3 As a heat seal layer, a low density polyethylene resin was laminated on the oxygen barrier layer obtained in Example 1 so as to have a thickness of 10 μm, and the same procedure as in Example 1 was carried out. A transparent barrier laminate was obtained. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Comparative Example 4> As a heat-sealing resin,
Acrylic styrene resin (trademark: LA812F6, solid content concentration 25%, manufactured by Clariant Polymer Co., Ltd.) 79% by mass,
And 21% by mass of MMA beads (trademark: MX180, particle diameter 1.8 μm, manufactured by Soken Chemical Industry Co., Ltd.) dispersed in pure water with a homomixer to have a solid content concentration of 1% were mixed and stirred. A transparent barrier laminate was obtained in the same manner as in Example 1 except for the above. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Comparative Example 5> An aqueous polyvinyl alcohol solution prepared as an oxygen barrier resin with a solid content concentration of 5% (trademark: PVA217, saponification degree 88%, manufactured by Kuraray Co., Ltd.).
A transparent barrier laminate was obtained in the same manner as in Example 1 except that was used. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

<Comparative Example 6> A transparent barrier laminate was obtained in the same manner as in Example 1 except that the oxygen barrier layer was not provided. Using the obtained samples, the moisture permeability, the oxygen permeability, the opacity, and the disintegration property were evaluated. The results are shown in Table 1.

[0052]

[Table 1]

As is clear from Table 1, an oxygen barrier layer composed of an oxygen barrier resin having hydrogen bonding properties on a transparent paper support, and a mixed composition of a thermoplastic resin and a wax. A heat-sealing layer and a transparent barrier layered product in which an inorganic layered compound and a cross-linking agent for a hydrogen-bonding group are added to the oxygen barrier layer as necessary are both oxygen barrier properties and moisture-proof properties. Good,
It can also be seen that it is excellent in transparency and disintegration (Examples 1 to 4).

On the other hand, when the opacity of the paper support to be used is high (Comparative Example 1), the visibility of the object to be packaged cannot be obtained when it is used as a packaging material, and conversely PE with excellent transparency is used.
When the T film base material is used (Comparative Example 2), the visibility of the packaged article is excellent, but the recyclability is impaired. Further, when a general polyethylene laminating process is performed as the heat seal layer (Comparative Example 3), the transparent barrier laminate has excellent moisture resistance and heat sealability, but the recyclability as waste paper is impaired. On the other hand, even when a thermoplastic resin having a disaggregation property is used, if the wax component is not blended at the same time (Comparative Example 4), sufficient moistureproof performance cannot be obtained. Not only is the protection insufficient, but the cohesive force of the oxygen barrier layer decreases due to the effect of humidity, and sufficient oxygen barrier properties cannot be obtained.

Further, when the cohesive force of the oxygen barrier resin used as the oxygen barrier layer after coating is insufficient (Comparative Example 5) and when the oxygen barrier layer itself is not provided (Comparative Example 6), In either case, it is difficult to obtain a satisfactory oxygen barrier property.

[0056]

INDUSTRIAL APPLICABILITY The present invention provides an oxygen barrier layer composed of an oxygen barrier resin having hydrogen bonding properties on a transparent paper support, and a heat seal composed of a mixed composition of a thermoplastic resin and a wax. By sequentially stacking the layers, it is possible to provide a transparent barrier laminate having high moisture resistance / oxygen barrier properties, excellent transparency, and recyclable as waste paper.

Continued front page    F term (reference) 4F100 AJ11C AK12C AK25C AK68B                       AL01C AR00B BA03 BA07                       BA10A DG10A GB15 JA20A                       JD03 JD03B JD04 JL01                       JL16 JN01 JN01A YY00                       YY00A                 4L055 AG04 AG51 AG59 AG63 AG64                       AG71 AG89 AH37 AJ01 AJ02                       AJ04 BB03 BE09 BE20 EA05                       EA12 EA13 EA20 FA12 FA30                       GA05 GA41 GA47 GA50

Claims (4)

[Claims] 1. A laminate comprising an oxygen barrier layer and a heat seal layer, which are sequentially laminated on at least one surface of a paper support, and which is JIS-K7126-B.
The value of oxygen permeability by law 100cc ^/ m 2 ^/ 24h ^/
Atm or less, the value of water vapor transmission rate according to JIS-Z0208-B method is 50 g / m ² · 24h · atm or less and JIS-P
A recyclable transparent barrier laminate characterized by having an opacity value of 40% or less according to 8138. 2. The paper support is pulp freeness 100.
A transparent paper mainly composed of pulp fibers beaten up to mlCSF or less, which is calendered with a roll having a water content of the paper support of 3 to 30% and a surface temperature of 80 ° C. or more. The recyclable transparent barrier laminate according to claim 1, which is used as a support. 3. The oxygen barrier layer has an ethylene content of 55.
2. An ethylene-vinyl acetate copolymer saponified product having a saponification degree of 90% or more and a polyvinyl alcohol having a saponification degree of 90% or more. A recyclable transparent barrier laminate. 4. The recyclable transparent barrier laminate according to claim 1, wherein the heat seal layer is composed of a mixed resin composition of a thermoplastic resin and a wax.