WO2021166910A1 - Gas barrier laminate - Google Patents

Abstract

The present invention addresses the problem of providing a gas barrier laminate which can exhibit satisfactory gas barrier properties even under a high-humidity environment. The present invention relates to a gas barrier laminate which has a water vapor barrier layer and a gas barrier layer in this order on at least one surface of a paper-made support, in which the water vapor barrier layer comprises a layered inorganic compound, a cationic resin and an anionic binder, and the gas barrier layer comprises a water-suspensible polymer.

Description

Gas barrier laminate

The present invention relates to a gas barrier laminate having paper as a support.

Conventionally, packaging materials that use paper as a base material and have water vapor barrier properties and gas barrier properties (particularly oxygen barrier properties) have been known. Such packaging materials are used in packaging of foods, medical products, electronic parts, etc. in order to prevent deterioration of the quality of the contents.

As a method of imparting water vapor barrier property or gas barrier property to a paper base material, a method of laminating a synthetic resin film or a metal foil having excellent gas barrier property using paper as a support is common. However, it is difficult to recycle paper, synthetic resin, and the like after use of a material in which a synthetic resin film or a metal foil is laminated on a paper base material, which poses an environmental problem.

Therefore, the development of a gas barrier material based on paper has been promoted without using a synthetic resin film or the like. For example, Patent Documents 1 and 2 disclose a paper barrier material in which a water vapor barrier layer and a gas barrier layer are provided in this order on a paper base material. In Patent Document 1, the water vapor barrier layer contains a water vapor barrier resin and a water repellent, and the gas barrier layer contains a water-soluble polymer and a surfactant. Further, Patent Document 2 discloses that the water vapor barrier layer and the gas barrier layer have a water-soluble polymer or a water-suspendable polymer. The binder resin for the gas barrier layer in Patent Document 2 is a polyvinyl alcohol resin.

Further, Patent Document 3 describes at least one of paper barrier base papers having a water vapor barrier layer and a gas barrier layer containing a water-soluble polymer on a paper substrate having a basis weight of 25 g / m ² or more and 400 g / m ^{2 or less.} A paper barrier material having a protective layer is disclosed on the surface of the paper.

International Publication No. 2017/170462 International Publication No. 2013/0697888 Japanese Unexamined Patent Publication No. 2018-0583360

As described above, a gas barrier laminate in which a water vapor barrier layer and a gas barrier layer are provided in this order on a paper base material is known, and the gas barrier layer contains polyvinyl alcohol as a water-soluble polymer. There is. However, according to the studies by the present inventors, it has been found that when a gas barrier layer containing polyvinyl alcohol is laminated on a paper substrate, sufficient gas barrier properties may not be exhibited in a high humidity environment.

Therefore, in order to solve the problems of the prior art, the present inventors have proceeded with studies for the purpose of providing a gas barrier laminate capable of exhibiting sufficient gas barrier even in a high humidity environment.

Specifically, the present invention has the following configuration.

[1] A gas-barrier laminate having a water vapor barrier layer and a gas barrier layer on at least one surface of the paper support in this order.
The water vapor barrier layer contains a layered inorganic compound, a cationic resin and an anionic binder,
A gas barrier laminate in which the gas barrier layer contains a water-suspendable polymer.
[2] The gas barrier laminate according to [1], wherein the water-suspendable polymer is at least one selected from a urethane resin and a vinylidene chloride resin.
[3] The gas barrier laminate according to [2], wherein the water-suspendable polymer is derived from a polymer dispersed in the emulsion, and the gas barrier layer is a coating layer of the emulsion.
[4] The water-suspendable polymer is a urethane-based resin.
When forming a sheet having a thickness of 25μm from urethane resin, 23 ° C. of the sheet, the oxygen permeability becomes ^{100mL / (m 2 · day ·} atm) or less at 50% relative humidity, any of [1] to [3] The gas barrier laminate described in Crab.
[5] The water-suspendable polymer is a urethane-based resin.
The urethane-based resin is described in any one of [1] to [4], which contains at least one selected from the group consisting of a structural unit derived from metaxylylene diisocyanate and a structural unit derived from hydrogenated metaxylylene diisocyanate. Gas barrier laminate.
[6] The total number of constituent units derived from metaxylylene diisocyanate and the number of constituent units derived from hydrogenated metaxylylene diisocyanate is 50% or more of the number of constituent units derived from polyisocyanate in the urethane resin. 5] The gas barrier laminate according to.
[7] The water-suspendable polymer is a urethane-based resin.
The gas barrier laminate according to any one of [1] to [6], wherein the urethane resin has a hydroxy group and has a hydroxyl value of 50 mgKOH / g or more.
[8] The gas barrier laminate according to any one of [1] to [7], wherein the gas barrier layer further contains a layered inorganic compound.
[9] The gas barrier laminate according to [8], wherein the layered inorganic compound contained in the gas barrier layer has an aspect ratio of 20 or more and a thickness of 200 nm or less.
[10] The gas barrier laminate according to [8] or [9], wherein the layered inorganic compound contained in the gas barrier layer is at least one selected from the group consisting of mica, bentonite and kaolin.
[11] The gas barrier laminate according to any one of [1] to [10], wherein the layered inorganic compound contained in the water vapor barrier layer has an aspect ratio of 20 or more and a thickness of 200 nm or less.
[12] The gas barrier laminate according to any one of [1] to [11], wherein the layered inorganic compound contained in the water vapor barrier layer is at least one selected from the group consisting of mica, bentonite and kaolin.
[13] The anionic binder is at least one selected from the group consisting of styrene-butadiene copolymers, styrene-acrylic copolymers and olefin / unsaturated carboxylic acid copolymers, [1] to The gas barrier laminate according to any one of [12].
[14] The gas barrier laminate according to any one of [1] to [13], wherein the cationic resin has a surface charge of 0.1 to 10 meq / g.
[15] The gas barrier laminate according to any one of [1] to [14], further having a sealant layer on at least one outermost layer.
[16] The gas barrier laminate according to [15], wherein the sealant layer contains a biodegradable resin.
[17] The gas barrier laminate according to any one of [1] to [16], which is a packaging material.

FIG. 1 is a cross-sectional view illustrating the configuration of the gas barrier laminated body of the present embodiment.

The gas barrier laminate of the present embodiment has a water vapor barrier layer and a gas barrier layer in this order on at least one surface of the paper support, and the water vapor barrier layer contains a layered inorganic compound, a cationic resin, and an anionic binder. , The gas barrier layer contains a water-suspendable polymer. The gas barrier laminate of the present embodiment can exhibit sufficient gas barrier even in a high humidity environment.
Hereinafter, the present embodiment will be described in detail. The description of the constituent elements described below may be based on typical embodiments or specific examples, but the present invention is not limited to such embodiments. In this specification, the numerical range represented by using "-" means a range including the numerical values before and after "-" as the lower limit value and the upper limit value.

(Gas barrier laminate)
The present embodiment relates to a gas barrier laminate having a water vapor barrier layer and a gas barrier layer on at least one surface of the paper support in this order. Here, the water vapor barrier layer contains a layered inorganic compound, a cationic resin and an anionic binder, and the gas barrier layer contains a water-suspendable polymer.

FIG. 1 is a cross-sectional view illustrating the configuration of the gas barrier laminate of the present embodiment. As shown in FIG. 1, the gas barrier laminate 100 of the present embodiment has a water vapor barrier layer 20 and a gas barrier layer 30 in this order on the paper support 10. Other layers may be included between the layers, but they are preferably laminated so as to be in direct contact with each other. That is, it is preferable that the water vapor barrier layer 20 is provided so as to be in direct contact with the paper support 10, and the gas barrier layer 30 is further provided so as to be in direct contact with the water vapor barrier layer 20.

In the gas barrier laminate of the present embodiment, the water vapor barrier layer contains a layered inorganic compound, a cationic resin and an anionic binder, and the gas barrier layer contains a water-suspendable polymer. Therefore, the gas barrier laminate of the present embodiment can exhibit excellent gas barrier properties. In particular, the gas barrier laminate of the present embodiment can exhibit excellent gas barrier properties under high humidity conditions.

The gas barrier property of the gas barrier laminate can be evaluated by measuring the oxygen permeability of the gas barrier laminate. The oxygen permeability of the gas barrier laminate is measured using an oxygen permeability measuring device. As the oxygen permeability measuring device, for example, OX-TRAN2 / 20 manufactured by MOCON can be used. In the present specification, the oxygen permeability under normal conditions is the oxygen permeability measured under the conditions of 23 ° C. and 50% relative humidity, and the oxygen permeability under high humidity conditions is 23 ° C. and 85% relative humidity. It is the oxygen permeability measured in.

The oxygen permeability of the gas barrier laminate of the present embodiment measured under the conditions of 23 ° C. and 85% relative humidity ^{is preferably 300 cc / m 2} · day · atm or less, preferably 250 cc / m ² · day · atm or less. It is more preferably 200 cc / m ² · day · atm or less, and ^{particularly preferably 150 cc / m 2} · day · atm or less. By changing the composition of the water vapor barrier layer, the oxygen permeability measured under the conditions of 23 ° C. and 85% relative humidity of the gas barrier laminate can be set to 100 cc / m ² · day · atm or less. Yes, the oxygen permeability of the gas barrier laminate measured at 23 ° C. and 85% relative humidity may be 0 cc / m ² · day · atm.

The oxygen permeability of the gas barrier laminate of the present embodiment measured under the conditions of 23 ° C. and 50% relative humidity ^{is preferably 50 cc / m 2} · day · atm or less, preferably 45 cc / m ² · day · atm or less. It is more preferably 40 cc / m ² · day · atm or less, and ^{particularly preferably 35 cc / m 2} · day · atm or less. By changing the composition of the water vapor barrier layer, the oxygen permeability measured under the conditions of 23 ° C. and 50% relative humidity of the gas barrier laminate can be set to 20 cc / m ² · day · atm or less. Yes, the oxygen permeability of the gas barrier laminate measured at 23 ° C. and 50% relative humidity may be 0 cc / m ² · day · atm. As described above, the gas barrier laminate of the present embodiment exhibits excellent gas barrier properties even under normal humidity conditions.

Further, in the gas barrier laminate of the present embodiment, the rate of increase in oxygen permeability can be suppressed to a low level even when the gas barrier laminate is placed under high humidity conditions. More specifically, in the gas barrier laminate of the present embodiment, the oxygen permeability ratio calculated by the following formula is preferably 300 or less, more preferably 200 or less, and 100 or less. More preferably, it is more preferably 75 or less, further preferably 50 or less, even more preferably 30 or less, particularly preferably 20 or less, and most preferably 15 or less. preferable.
Oxygen permeability ratio = 23 ° C, oxygen permeability at relative humidity 85% (cc / m ² · day · atm) / 23 ° C, oxygen permeability at relative humidity 50% (cc / m ² · day · atm)
When the oxygen permeability ratio calculated by the above formula is within the above range, it can be determined that the rate of increase in oxygen permeability when the gas barrier laminate is placed under high humidity conditions is low. Further, if the oxygen permeability ratio is within the above range, it can be evaluated that the humidity dependence of the oxygen permeability in the gas barrier laminate is small.

The water vapor transmission rate of the gas barrier laminate of the present embodiment ^{is preferably 50 g / m 2} · day or less, ^{more preferably 40 g / m 2} · day or less, and 30 g / m ² · day or less. It is more preferable, and it is particularly preferable that it is ^{25 g / m 2 · day or less.} If the water vapor transmission rate of the gas barrier laminate is within the above range, it can be said that the water vapor permeability of the gas barrier laminate is sufficiently suppressed. Here, the water vapor transmission rate of the gas barrier laminate is a value measured in accordance with JIS Z 0208: 1976 (cup method) B method (40 ° C ± 0.5 ° C, relative humidity 90% ± 2%). be. When measuring, the gas barrier layer is on the inside.

The contact angle of the surface of the gas barrier layer of the gas barrier laminate of the present embodiment is preferably 10 ° or more, more preferably 20 ° or more, and further preferably 30 ° or more. The upper limit of the contact angle on the surface of the gas barrier layer of the gas barrier laminate is not particularly limited, but is preferably 60 ° or less. When the contact angle of the surface of the gas barrier layer of the gas barrier laminate is 10 ° or more, the gas barrier laminate can also exhibit excellent water repellency. The contact angle of the surface of the gas barrier layer of the gas barrier laminate in the present specification is a value measured 60 seconds after dropping 4 μl of water on the surface of the gas barrier layer of the gas barrier laminate. As the contact angle measuring device, for example, a dynamic contact angle measuring device DAT1100 manufactured by Matsubo Co., Ltd. can be used.

Furthermore, the gas barrier laminate of the present embodiment is also excellent in water resistance. Specifically, stickiness and dissolution of the gas barrier layer are suppressed even after water is dropped onto the gas barrier layer of the gas barrier laminate. As described above, the gas barrier laminate of the present specification is not only excellent in gas barrier property but also excellent in water repellency and water resistance. Therefore, for example, it is preferable under high humidity conditions and in a water use environment. Can be used.

The thickness of the gas barrier laminate is preferably 10 μm or more, more preferably 20 μm or more, and further preferably 30 μm or more. The thickness of the gas barrier laminate is preferably 500 μm or less, more preferably 400 μm or less, and further preferably 300 μm or less.

(Paper support)
The paper support used in the present embodiment is not particularly limited as long as it is a paper generally used with plant-derived pulp as a main component. Examples of the paper include bleached or unbleached kraft paper, high-quality paper, paperboard, liner paper, coated paper, single-gloss paper, glassin paper, and graphan paper. The paper support is preferably made of paper containing pulp as a main component, which is easily dispersed in water by a mechanical dissociation action.

The dissociation freeness (water drainage degree) measured according to JIS P 8121: 2012 of the paper support is preferably 800 ml or less, and more preferably 500 ml or less, from the viewpoint of improving the gas barrier property. Here, the dissociation freeness is the Canadian standard freeness of pulp obtained by dissociating the paper after papermaking in accordance with JIS P 820-1: 2012 and measuring it in accordance with JIS P 8121: 2012. That is. Examples of the method for adjusting the dissociation freeness include a method of beating pulp. As a method for beating pulp, a known method can be adopted.

The basis weight of the paper support is not particularly limited, but is preferably 20 ~ 400g / ^{m 2,} more preferably 30 ~ 320g / ^{m 2.}

The thickness of the paper support is not particularly limited, but is preferably 10 to 200 μm, and more preferably 20 to 100 μm.

The density of the paper support is not particularly limited, ^{but is preferably 0.3 to 1.5 g / cm 3} , and more preferably 0.5 to 1.0 g / cm ³ .

The Oken-type smoothness of the surface of the paper support on the side where the water vapor barrier layer is provided is preferably 5 seconds or longer, more preferably 10 seconds or longer, and even more preferably 15 seconds or longer. By setting the smoothness of the surface of the paper support on the side where the water vapor barrier layer is provided to 5 seconds or more, a smoother water vapor barrier layer is formed, so that the water vapor barrier property of the gas barrier laminate is further improved. do. The upper limit of the Oken-type smoothness of the surface of the paper support on which the water vapor barrier layer is provided is not particularly limited, but is preferably 1000 seconds or less. Here, for the Oken-type smoothness of the surface of the paper support, a value measured in accordance with JIS P 8155: 2010 shall be adopted.

The size of the paper support is not particularly limited, but from the viewpoint of improving the barrier property, it is preferable that the size of the paper support is 1 second or more according to JIS P 8122: 2004. The size of the paper support is determined by the type and content of internal sizing agents such as rosin, alkyl ketene dimer, alkenyl succinic anhydride, styrene-acrylic, higher fatty acid, and petroleum resin, and the type of pulp. It can be controlled by smoothing or the like. The content of the internal sizing agent is not particularly limited, but is preferably 0 to 3 parts by mass with respect to 100 parts by mass of the pulp in the paper support.

Further, a known internal chemical can be appropriately added to the paper support. Examples of internal chemicals include fillers such as titanium dioxide, kaolin, talc, and calcium carbonate, paper strength enhancers, yield improvers, pH adjusters, drainage improvers, water resistance agents, fabric softeners, and antistatic agents. Examples thereof include defoaming agents, slime control agents, dyes and pigments.

(Water vapor barrier layer)
The water vapor barrier layer is a layer having a function of blocking the permeation of water vapor, and contains a layered inorganic compound, a cationic resin, and an anionic binder.

<Layered inorganic compound>
The form of the layered inorganic compound is flat. Then, in the water vapor barrier layer, the flat layered inorganic compounds are arranged in a state of being laminated substantially parallel to the plane (surface) of the paper support. In this state, the area where the layered inorganic compound does not exist becomes smaller in the plane direction, so that the permeation of water vapor is suppressed. In addition, since the flat layered inorganic compounds exist in parallel to the plane of the paper support in the thickness direction, the water vapor that has entered the layer permeates while bypassing the layered inorganic compound, and the water vapor Permeation is suppressed. As a result, the water vapor barrier layer can exhibit excellent water vapor barrier properties.

The average length of the layered inorganic compound is preferably 1 to 100 μm, more preferably 2 to 50 μm, and even more preferably 3 to 20 μm. Here, the average length of the layered inorganic compound is the average length of the long axis in the plane direction of the layered inorganic compound. When the average length is 1 μm or more, the layered inorganic compounds in the water vapor barrier layer are likely to be arranged parallel to the paper support. Further, when the average length is 100 μm or less, there is less concern that a part of the layered inorganic compound protrudes from the water vapor barrier layer.

The aspect ratio of the layered inorganic compound is preferably 20 or more, more preferably 50 or more, and even more preferably 80 or more. Further, from the viewpoint of reducing the coating amount of the water vapor barrier layer and enhancing the recyclability and lightness of the gas barrier laminate, the aspect ratio of the layered inorganic compound is preferably 100 or more, preferably 200 or more. More preferably, it is more preferably 300 or more, and particularly preferably 500 or more. The upper limit of the aspect ratio of the layered inorganic compound is not particularly limited, but is preferably 10,000 or less. Here, the aspect ratio is a value calculated from a microscopic magnified photograph of a cross section of the water vapor barrier layer, and is an average value of values obtained by dividing the length of the layered inorganic compound by its thickness. By setting the aspect ratio of the layered inorganic compound within the above range, the water vapor barrier layer can exhibit more excellent water vapor barrier properties. Further, by setting the aspect ratio of the layered inorganic compound within the above range, the amount of the layered inorganic compound added to the water vapor barrier layer can be reduced.

The thickness of the layered inorganic compound is preferably 200 nm or less, more preferably 100 nm or less, and further preferably 50 nm or less. The lower limit of the thickness of the layered inorganic compound is not particularly limited, but is preferably 2 nm or more. Here, the thickness of the layered inorganic compound is the average thickness of the layered inorganic compound measured from a microscopic magnified photograph of a cross section of the water vapor barrier layer. By setting the average thickness of the layered inorganic compound within the above range, the number of layers of the layered inorganic compound in the water vapor barrier layer is increased, so that the water vapor barrier layer can exhibit higher water vapor barrier properties. In particular, when a layered inorganic compound having a large aspect ratio and a small thickness is used, the water vapor barrier layer forms a dense film without voids. This is a phenomenon that can be observed from a microscopic magnified photograph of the cross section of the water vapor barrier layer. Such a dense film structure of the water vapor barrier layer without voids can form a tough film and effectively suppress cracking. Further, since it is possible to suppress the penetration of the coating liquid of the gas barrier layer laminated on the water vapor barrier layer, it also contributes to the formation of a uniform gas barrier layer.

In the present embodiment, the aspect ratio of the layered inorganic compound contained in the water vapor barrier layer is 20 or more (preferably 50 or more, more preferably 80 or more), and the thickness is 200 nm or less.

Specific examples of layered inorganic compounds include mica such as mica and brittle mica, bentonite, kaolinite (kaolin mineral, hereinafter also referred to as "kaolin"), pyrophyllite, talc, smectite, vermiculite, chlorite, and septe green mud. Examples include stones, serpentine stones, stirp nomelene, and montmorillonite. Among these, from the viewpoint of improving the water vapor barrier property, the layered inorganic compound is preferably at least one selected from the group consisting of mica, bentonite and kaolin, and at least one selected from mica and kaolin. It is preferable to be there. As mica, synthetic mica, white mica (mascobite), sericite (serisite), gold mica (frocopite), black mica (biotight), fluorine gold mica (artificial mica), red mica, soda mica, vanazin mica, Elite, chimmica, paragonite, brittle mica, etc. Among them, swelling mica is preferable as mica because it has a high aspect ratio. Further, the kaolin may be a natural product or a synthetic product (engineered kaolin). Among them, engineered kaolin is preferable because it has a high aspect ratio. Moreover, as a bentonite, montmorillonite can be mentioned.

The content of the layered inorganic compound is preferably 90% by mass or less, more preferably 80% by mass or less, and 75% by mass or less, based on the total solid content mass contained in the water vapor barrier layer. More preferably, it is more preferably 70% by mass or less. On the other hand, the content of the layered inorganic compound is preferably 1% by mass or more, more preferably 2% by mass or more, and 5% by mass or more, based on the total solid content mass contained in the water vapor barrier layer. Is more preferable, and 10% by mass or more is particularly preferable. In the present embodiment, the content of the layered inorganic compound may be reduced by increasing the aspect ratio and decreasing the thickness of the layered inorganic compound. Further, by increasing the strength of the water vapor barrier layer, it is possible to prevent the layered inorganic compound from falling off from the water vapor barrier layer.

The content of the layered inorganic compound is preferably 0.1 to 800 parts by mass, more preferably 1 to 500 parts by mass, and 2 to 400 parts by mass with respect to 100 parts by mass of the anionic binder in the water vapor barrier layer. It is more preferably parts by mass, more preferably 5 to 300 parts by mass, and particularly preferably 10 to 250 parts by mass. When the content of the layered inorganic compound is at least the above lower limit value, the water vapor barrier property is likely to be exhibited. Further, by setting the content of the layered inorganic compound to the above upper limit value or less, it is possible to suppress that a part of the layered inorganic compound is exposed from the surface of the water vapor barrier layer to increase the water vapor transmission rate. Further, by setting the content of the layered inorganic compound to the above upper limit value or less, the coatability of the gas barrier layer laminated on the water vapor barrier layer can be improved.

<Cationic resin>
The water vapor barrier layer contains a cationic resin. By further adding a cationic resin in addition to the layered inorganic compound to the water vapor barrier layer, the water vapor barrier property can be greatly improved.

The reasons for improving the water vapor barrier property by adding the cationic resin include, for example, the following reasons. It is known that the layered inorganic compound has a so-called card house structure in which the flat portion of the flat plate-like form is easily charged anionic and the edge portion is cationically charged, so that the layered inorganic compounds are three-dimensionally aggregated with each other. ing. Due to such a card house structure, the viscosity of the aqueous dispersion of the layered inorganic compound tends to be high. On the other hand, since the card house structure is easily broken when a force is applied by stirring or the like, the aqueous dispersion of the layered inorganic compound exhibits high thixotropy. When an appropriate cationic resin is added thereto, the cationic resin is adsorbed on the anionic flat portion of the layered inorganic compound, and the card house structure is destroyed. As a result, it is presumed that the three-dimensional aggregation of the layered inorganic compound is suppressed, the flat layered inorganic compound is easily laminated in parallel with the plane of the paper support, and the water vapor barrier property is improved. ..

Specific examples of the cationic resin include polyalkylene polyamines, polyamide compounds, polyamideamine-epihalohydrin or polyamideamine-epihalohydrin formaldehyde condensation reaction products, polyamine-epihalohydrin or polyamine-epihalohydrin formaldehyde condensation reaction products, and polyamide polyurea-. Formaldehyde condensation reaction product of epihalohydrin or polyamide polyurea-epihalohydrin, formaldehyde condensation reaction product of polyamine polyurea-epihalohydrin or polyamine polyurea-epihalohydrin, polyamideamine polyurea-epihalohydrin or polyamideamine polyurea-epihalohydrin Examples thereof include products, polyamide polyurea compounds, polyamine polyurea compounds, polyamideamine polyurea compounds and polyamideamine compounds, polyethyleneimines, polyvinylpyridines, amino-modified acrylamide compounds, polyvinylamines, polydialyldimethylammonium chlorides and the like. Above all, the cationic resin is preferably a polyamide compound.

The surface charge of the cationic resin is preferably 0.1 to 10 meq / g, more preferably 0.1 to 5.0 meq / g, and preferably 0.1 to 2.0 meq / g. It is more preferably 0.2 to 1.0 meq / g, and particularly preferably 0.2 to 1.0 meq / g. When the surface charge of the cationic resin is within the above numerical range, the card house structure can be easily destroyed, and the anionic binder described later can coexist appropriately. The surface charge of the cationic resin is measured by the method described below. First, the polymer as a sample is dissolved in water to obtain a solution having a polymer concentration of 1 ppm. 0.001N sodium polyethylene sulfonate is added dropwise to the solution using a charge analyzer Mutek PCD-04 (manufactured by BTG), and the amount of charge is measured.

The content of the cationic resin may be appropriately selected according to the type of the layered inorganic compound used for the water vapor barrier layer and the anionic binder, but from the viewpoint of improving the water vapor barrier property, the content of the layered inorganic compound is 100 parts by mass. On the other hand, it is preferably 0.01 to 300 parts by mass, more preferably 0.1 to 250 parts by mass, further preferably 0.5 to 150 parts by mass, and 1 to 100 parts by mass. It is even more preferably 1 to 20 parts by mass, and particularly preferably 1 to 5 parts by mass. The content of the cationic resin is preferably 0.1 to 100 parts by mass, more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the anionic binder in the water vapor barrier layer. 1 to 20 parts by mass is more preferable, and 2 to 15 parts by mass is particularly preferable.

<Anionic binder>
The water vapor barrier layer further contains an anionic binder. When the water vapor barrier layer contains an anionic binder, the water vapor barrier property of the water vapor barrier layer can be enhanced more effectively. This is because, as described above, the flat portion of the layered inorganic compound is anionic, but when the cationic resin is adsorbed, the surface becomes cationic, and as a result, the affinity with the anionic binder is enhanced. It is thought that this is due to.

Examples of the anionic binder include a binder containing a monomer unit containing an anionic group. Among them, the anionic binder is preferably a binder containing a monomer unit containing a carboxy group. Examples of the anionic binder include styrene / butadiene copolymers, styrene / acrylic copolymers, methacrylate / butadiene copolymers, acrylic nitrile / butadiene copolymers, olefin / unsaturated carboxylic acid copolymers, and the like. Acrylic ester-based polymers and the like can be mentioned. Among these, the anionic binders are styrene-butadiene copolymers, styrene-acrylic copolymers and olefins because they have good water resistance, good elongation, and are less likely to crack the coating layer due to cracking. -It is preferable that it is at least one selected from the group consisting of unsaturated carboxylic acid-based copolymers, and more preferably it is an olefin / unsaturated carboxylic acid-based copolymer.

Styrene-butadiene copolymers include styrene compounds such as styrene, α-methylstyrene, vinyltoluene, pt-butylstyrene, and chlorostyrene, and 1,3-butadiene and isoprene (2-methyl-1,3). -Butadiene), 2,3 dimethyl-1,3-butadiene, 1,3-pentadiene and other conjugated diene compounds, and copolymers obtained by copolymerizing a monomer composed of other compounds copolymerizable with these compounds. It is a copolymer. Styrene is preferable as the styrene compound, and 1,3-butadiene is preferable as the conjugated diene compound.

Styrene-acrylic copolymers include styrene-based compounds such as styrene, α-methylstyrene, vinyltoluene, pt-butylstyrene, and chlorostyrene, and acrylic acid, methacrylic acid, (meth) acrylic acid ester, and (meth) acrylic acid ester. ) Emulsion polymerization of a monomer composed of acrylic compounds such as acrylamide propane sulfonic acid and sulfoalkyl sodium salt (meth) acrylate (alkyl group having 2 or more and 3 or less carbon atoms) and other compounds copolymerizable with these compounds. It is a copolymer obtained by the above. As the styrene-based compound, styrene is preferable, and as the acrylic-based compound, acrylic acid, methacrylic acid, acrylic acid ester, and methacrylic acid ester are preferable, and acrylic acid and acrylic acid ester are more preferable. The (meth) acrylic acid ester is preferably an acrylic acid alkyl ester, and in this case, the alkyl group preferably has 1 to 6 carbon atoms.

Olefin / unsaturated carboxylic acid-based copolymers include olefins, especially α-olefins such as ethylene and propylene, acrylic acid, methacrylic acid, crotonic acid, silicic acid, itaconic acid, fumaric acid, maleic acid, and butentricarboxylic acid. Unsaturated polycarboxylic acid alkyl esters with at least one carboxyl group, such as unsaturated carboxylic acids such as itaconic acid monoethyl ester, fumaric acid monobutyl ester and maleic acid monobutyl ester, acrylamide propanesulfonic acid, acrylic acid. A copolymer obtained by emulsifying and polymerizing an unsaturated sulfonic acid monomer such as a sulfoethyl sodium salt or a sulfopropyl sodium methacrylate salt or a salt thereof, and a monomer composed of other compounds copolymerizable therewith. Is. As the olefin, α-olefin, especially ethylene and the like are preferable, and as the unsaturated carboxylic acid monomer, unsaturated sulfonic acid monomer or a salt thereof, acrylic acid, methacrylic acid, itaconic acid, fumaric acid and the like are used. Is preferable. Specific examples of the olefin / unsaturated carboxylic acid-based copolymer include, for example, an aqueous dispersion of an ammonium salt of an ethylene / acrylic acid copolymer, Zyxene® AC or the like (copolymerization ratio of acrylic acid 21.1 mass). %, Made by Sumitomo Seika Co., Ltd.).

The above-mentioned anionic binder may be further copolymerized with other copolymerizable compounds. Specific examples of other copolymerizable compounds include cyano group-containing ethylenically unsaturated compounds, ethylenically unsaturated acid glycidyl ethers, unsaturated alcohol glycidyl ethers, and (meth) acrylamide compounds.

The method for producing the anionic binder is not particularly limited. For example, it can be obtained by copolymerizing a monomer containing a carboxy group (for example, an unsaturated carboxylic acid) and a monomer copolymerizable therewith. Alternatively, for example, it can be obtained by introducing a monomer containing a carboxy group into a polymer and modifying it. The copolymerization ratio of the monomer containing a carboxy group is preferably 1 to 50 mol%.

The weight average molecular weight of the anionic binder is preferably 10,000 to 10 million, more preferably 100,000 to 5 million. By setting the weight average molecular weight of the anionic binder within the above range, the viscosity of the coating liquid for forming the water vapor barrier layer can be set within an appropriate range. For the weight average molecular weight, a polystyrene-equivalent value measured by gel permeation chromatography shall be adopted.

The content of the anionic binder is not particularly limited, but is preferably 10% by mass or more, more preferably 15% by mass or more, and 20% by mass with respect to the total solid content mass contained in the water vapor barrier layer. % Or more is more preferable, 25% by mass or more is particularly preferable, and 30% by mass or more is most preferable. The content of the anionic binder is preferably 95% by mass or less, more preferably 90% by mass or less, and 85% by mass or less, based on the total solid content mass contained in the water vapor barrier layer. Is more preferable, and 80% by mass or less is particularly preferable.

<Arbitrary ingredient>
In the water vapor barrier layer, in addition to the layered inorganic compound, the cationic resin and the anionic binder, a dispersant, a surfactant, a defoaming agent, a wetting agent, a dye, a color adjusting agent, a thickener and the like are appropriately added as needed. It can be added.

The thickness of the water vapor barrier layer is preferably 1 to 30 μm, more preferably 3 to 20 μm. The coating amount of the water vapor barrier layer ^{is preferably 1 to 30 g / m 2} and more preferably 3 to 20 g / m ² as the solid content.

(Gas barrier layer)
The gas barrier layer is a layer having a function of mainly blocking the permeation of oxygen gas, and contains a water-suspendable polymer.

<Water-suspendable polymer>
The water-suspendable polymer used in the present embodiment is a polymer having a solubility in water at 25 ° C. of 10 g / L or less. In the present embodiment, the water-suspendable polymer is preferably derived from the polymer (particles) dispersed in the emulsion.

Examples of the water-suspendable polymer include urethane-based resin, vinylidene chloride-based resin, olefin resin, polyester resin, nylon resin, epoxy resin, melamine resin, polyvinyl alcohol-based resin, acrylonitrile-based resin, and polycarboxylic acid-based resin. Examples thereof include silicone resin. The water-suspendable polymer may be used alone or in combination of two or more. Above all, from the viewpoint of further enhancing the gas barrier property in a high humidity environment, the water-suspendable polymer is preferably at least one selected from urethane-based resin and vinylidene chloride-based resin. By using a urethane resin or a vinylidene chloride resin as the water-suspendable polymer, the gas barrier property of the gas barrier laminate can be enhanced under high humidity conditions.

Urethane-based resin can be manufactured by a known manufacturing method. For example, a urethane resin can be obtained by reacting a polyisocyanate compound (for example, a diisocyanate compound) with a polyhydroxy acid (for example, dihydroxyic acid). Further, for example, in addition to the above-mentioned polyisocyanate compound and polyhydroxyic acid, it can also be obtained by reaction with a polyol compound (for example, polyester polyol, polyether polyol) and / or a chain extender.

The urethane-based resin preferably contains at least one selected from the group consisting of a structural unit derived from metaxylylene diisocyanate and a structural unit derived from hydrogenated metaxylylene diisocyanate. Since such a urethane-based resin exhibits a high cohesive force due to a hydrogen bond and a stacking effect between xylylene groups, the gas barrier layer tends to exhibit excellent gas barrier properties.

The total number of constituent units derived from metaxylylene diisocyanate and the number of constituent units derived from hydrogenated metaxylylene diisocyanate is preferably 50% or more with respect to the total number of constituent units derived from polyisocyanate in the urethane resin. The number of each structural unit can be identified using a known analytical method such as ^{1 1 H-NMR.}

The urethane resin may have a hydroxy group, and its hydroxyl value is preferably 50 mgKOH / g or more, more preferably 100 mgKOH / g or more, and further preferably 150 mgKOH / g or more. The upper limit of the hydroxyl value is not particularly limited, but is preferably 1000 mgKOH / g or less, more preferably 800 mgKOH / g or less, and further preferably 600 mgKOH / g or less. When the hydroxyl value of the urethane resin is within the above range, the gas barrier layer tends to exhibit oxygen barrier properties. Further, by setting the hydroxyl value of the urethane resin within the above range, the heat-sealing property of the gas barrier layer can be enhanced, and as a result, the heat-sealing property of the gas barrier laminated body can be enhanced.

When a sheet having a thickness of 25 μm is formed from a urethane resin, the oxygen permeability of the obtained sheet at 23 ° C. and 50% relative humidity ^{is preferably 100 mL / (m 2} · day · atm) or less, preferably 50 mL / (m). more preferably ² · day · atm) or less, further preferably ^{25mL / (m 2 · day ·} atm) or less, and particularly preferably ^{10mL / (m 2 · day ·} atm) or less. Incidentally, 23 ° C. of the resulting sheet, the oxygen permeability at 50% relative humidity may be ^{0mL / (m 2 · day ·} atm). In the present specification, the oxygen permeability of the sheet made of urethane resin is set to 23 ° C. and 50% relative humidity by using an oxygen permeability measuring device (OX-TRAN2 / 22 manufactured by MOCON). Is measured.

The glass transition temperature of the urethane resin is preferably 150 ° C. or lower, more preferably 140 ° C. or lower, and particularly preferably 135 ° C. or lower. The lower limit of the glass transition temperature of the urethane resin is not particularly limited, but is preferably 50 ° C. or higher, more preferably 60 ° C. or higher. The glass transition temperature of the urethane resin is measured in accordance with JIS K 7122: 2012.

As the urethane-based resin, a synthetic product may be used, and examples of the synthetic product include the urethane-based resin described in International Publication No. 2015/016069. As the urethane-based resin, a commercially available product may be used. For example, "Takelac W-based (trade name)", "Takelac WPB-based (trade name)", and "Takelac WS-based" manufactured by Mitsui Chemicals, Inc. ( Product name) ”and the like, and specifically, Takelac WPB-341 is exemplified. Other commercially available products include "HPU W-003" (hydroxyl value 235 mgKOH / g) manufactured by Dainichiseika Kogyo Co., Ltd.

The vinylidene chloride resin can be produced by a known production method. For example, the vinylidene chloride-based resin can be obtained from a homopolymer of vinylidene chloride (polyvinylidene chloride, PVDC), a copolymer of vinylidene chloride and a monomer copolymerizable with vinylidene chloride, and the like. The monomer copolymerizable with vinylidene chloride is not particularly limited, but (meth) acrylic acid esters such as vinyl chloride, methyl (meth) acrylate, ethyl (meth) acrylate, and butyl (meth) acrylate. , Acrylonitrile, isobutylene, vinyl acetate and the like.

As the vinylidene chloride-based resin, a commercially available product may be used, and examples thereof include "Saran Latex L549B" manufactured by Asahi Kasei Corporation and "Diofan A050, A297, B204" manufactured by SOLVAY.

The weight average molecular weight of the water-suspended polymer is preferably 1000 to 2000000000, and more preferably 5000 to 5000000. For the weight average molecular weight, a polystyrene-equivalent value measured by gel permeation chromatography shall be adopted.

When the water-suspendable polymer is derived from the polymer (particles) dispersed in the emulsion, the average particle size of the water-suspendable polymer in the emulsion is 0.001 to 100 μm. It is preferably 0.01 to 10 μm, and more preferably 0.01 to 10 μm. The average particle size can be measured by a dynamic light scattering method.

The content of the water-suspendable polymer is preferably 10 to 100% by mass, more preferably 20 to 100% by mass, and 30 to 30 to 100% by mass, based on the total solid content contained in the gas barrier layer. By setting the content of the water-suspendable polymer, which is more preferably 100% by mass and particularly preferably 40 to 100% by mass, within the above range, the gas barrier of the gas barrier laminate under high humidity conditions Sex can be enhanced more effectively.

As described above, the water-suspendable polymer is preferably derived from the polymer (particles) dispersed in the emulsion. In this case, the gas barrier layer is preferably a layer formed by applying an emulsion. In the present specification, the gas barrier layer thus formed may be referred to as an emulsion coating layer. In the present embodiment, from the viewpoint of further improving the gas barrier property, the gas barrier layer is a urethane-based resin emulsion (also referred to as "urethane-based emulsion" in the present specification) and a vinylidene chloride-based resin emulsion (in the present specification, ". It is particularly preferable that the coating layer is at least one selected from "vinylidene chloride-based emulsion").

It is preferable that the gas barrier layer contains a layered inorganic compound in addition to the above-mentioned water-suspendable polymer. By containing the layered inorganic compound in the gas barrier layer, the gas barrier property can be further enhanced (oxygen permeability can be further reduced). Examples of the layered inorganic compound include layered inorganic compounds that can be contained in the water vapor barrier layer as described above, and one type may be used alone or two or more types may be used in combination. The preferable ranges of the average length, aspect ratio and thickness of the layered inorganic compound are the same as the ranges described in the above section <Layered Inorganic Compound>. Above all, the aspect ratio of the layered inorganic compound contained in the gas barrier layer is 20 or more (preferably 50 or more, more preferably 80 or more), and the thickness is preferably 200 nm or less. By containing the layered inorganic compound having the above aspect ratio and thickness, the gas barrier property of the gas barrier property laminate (particularly under high humidity conditions) can be more effectively enhanced. Further, specific examples of the layered inorganic compound contained in the gas barrier layer are the same as the specific examples described in the above section <Layered inorganic compound>. Among them, at least one selected from the group consisting of mica, bentonite and kaolin is preferable, and at least one selected from mica and kaolin is more preferable. When the gas barrier layer contains the layered inorganic compound as described above, the gas barrier property of the gas barrier laminated body under high humidity conditions can be more effectively enhanced. The layered inorganic compound contained in the gas barrier layer may be of the same type as the layered inorganic compound contained in the water vapor barrier layer, or may be of a different type.

From the viewpoint of reducing the oxygen permeability ratio (humidity dependence of oxygen permeability) of the gas barrier laminate, the gas barrier layer preferably contains two or more layered inorganic compounds having different aspect ratios. Specifically, the gas barrier layer preferably contains a layered inorganic compound having an aspect ratio of less than 500 (layered inorganic compound A) and a layered inorganic compound having an aspect ratio of 500 or more (layered inorganic compound B). The aspect ratio of the layered inorganic compound A is more preferably 20 to 300, and particularly preferably 50 to 200. The aspect ratio of the layered inorganic compound B is more preferably 500 to 5000, still more preferably 750 to 2500. The layered inorganic compound A may be used alone or in combination of two or more. The layered inorganic compound B may be used alone or in combination of two or more.

When the layered inorganic compound is contained in the gas barrier layer, the content of the layered inorganic compound is not particularly limited, but is 0.5 to 500 parts by mass with respect to 100 parts by mass of the water-suspendable polymer in the gas barrier layer. It is preferably 1 to 300 parts by mass, more preferably 2 to 200 parts by mass, and particularly preferably 5 to 150 parts by mass. By setting the content of the layered inorganic compound within the above range, the gas barrier property of the gas barrier laminated body under high humidity conditions can be more effectively enhanced.

<Arbitrary ingredient>
In the gas barrier layer, in addition to the water-suspendable polymer and the layered inorganic compound, pigments, dispersants, surfactants, defoamers, wetting agents, dyes, color adjusters, thickeners, etc. are appropriately added as needed. It may be contained.

The thickness of the gas barrier layer is preferably 0.1 to 10 μm, more preferably 0.5 to 5 μm. Further, the coating amount of the gas barrier layer, as a solid content, preferably from 0.1 ~ 10g / ^{m 2,} more preferably 0.5 ~ 5g / ^{m 2.}

(Sealant layer)
The gas barrier laminate has a water vapor barrier layer and a gas barrier layer in this order on at least one surface of the paper support, and further has a sealant layer on at least one outermost layer of the gas barrier laminate. You may. That is, the sealant layer may be formed on the gas barrier layer on the side where the water vapor barrier layer and the gas barrier layer are formed, or the paper support on the side where the water vapor barrier layer and the gas barrier layer are not formed. It may be formed on top. Further, the sealant layer may be formed on the outermost layers on both sides of the gas barrier laminate.

The sealant layer is preferably a layer that is melted by heating or ultrasonic waves to exhibit adhesiveness. Thereby, for example, in the sealant layer, the gas barrier laminates can be bonded to each other by heat sealing or the like.

The sealant layer can be formed by laminating synthetic resins such as polyethylene, polypropylene, ethylene-vinyl acetate polymer, and polyvinyl acetate polymer by melt extrusion laminating method or dry laminating method. The sealant layer can also be formed by applying an emulsified dispersion of a synthetic resin such as polyethylene, polypropylene, an ethylene-vinyl acetate polymer, or a polyvinyl acetate polymer.

The sealant layer preferably contains a biodegradable resin. Specific examples of the biodegradable resin are not particularly limited, and for example, polylactic acid (PLA), polybutylene succinate (PBS), polybutylene succinate adipate (PBSA), 3-hydroxybutanoic acid / 3-hydroxyhexanoic acid. Copolymers (PHBH) and the like can be mentioned.

The thickness of the sealant layer is preferably 1 to 50 μm, more preferably 3 to 30 μm. The amount of the sealant layer formed ^{is preferably 1 to 50 g / m 2} and more preferably 3 to 30 g / m ² as the solid content.

(Use)
The gas barrier laminate of the present embodiment can be suitably used as a packaging material for foods, medical products, electronic parts, etc. by taking advantage of the above-mentioned excellent water vapor barrier properties and gas barrier properties. In particular, since the gas barrier laminate of the present embodiment has excellent gas barrier properties under high humidity conditions, it is suitably used as a packaging material for foods, medical products, electronic parts, etc. exposed to high humidity conditions. Can be done. Further, in the gas barrier laminate of the present embodiment, the humidity dependence of oxygen permeability is suppressed to be small, so that even if the temperature or humidity changes during transportation or storage, for example, the gas barrier It is possible to retain the gas barrier property of the laminated body without changing it.

(Manufacturing method of gas barrier laminate)
In the gas barrier laminate, the water vapor barrier layer forming coating liquid is first applied on the paper support to form the water vapor barrier layer, and then the gas barrier layer forming coating liquid is applied to form the gas barrier layer. Can be manufactured by forming. That is, the method for producing the gas barrier laminate is a step of applying a coating liquid for forming a water vapor barrier layer on a paper support to form a water vapor barrier layer, and a coating for forming a gas barrier layer on the water vapor barrier layer. It includes a step of applying a working liquid to form a gas barrier layer. In addition, each layer may be formed by sequentially coating and drying a coating liquid, or may be dried after simultaneous multi-layer coating.

In the process of forming the water vapor barrier layer, a coating liquid for forming the water vapor barrier layer is applied on the paper support. The coating liquid for forming a water vapor barrier layer contains a layered inorganic compound, a cationic resin and an anionic binder. The coating liquid for forming the water vapor barrier layer also contains a solvent, and as the solvent, water or an organic solvent such as ethanol, isopropyl alcohol, methyl ethyl ketone or toluene can be used.

As the coating equipment for applying the coating liquid for forming the water vapor barrier layer to the paper support, known equipment can be used. Examples of the coating equipment include a blade coater, a bar coater, an air knife coater, a slit die coater, a gravure coater, a micro gravure coater, and a gate roll coater. In particular, for forming the water vapor barrier layer, a coater that scrapes the coated surface, such as a blade coater, a bar coater, an air knife coater, and a slit die coater, is preferable in that it promotes the orientation of the layered inorganic compound.

In the step of forming the gas barrier layer, it is preferable to apply an emulsion containing a water-suspendable polymer onto the water vapor barrier layer. In particular, the step of forming the gas barrier layer is preferably a step of coating at least one selected from a urethane-based emulsion and a vinylidene chloride-based emulsion. When the gas barrier layer contains a layered inorganic compound or the like in addition to the water-suspendable polymer, it is preferable to apply a coating liquid in which the layered inorganic compound or the like is dispersed in the emulsion.

Examples of the coating equipment for coating the gas barrier layer coating liquid on the water vapor barrier layer include the same equipment as the above-mentioned equipment.

The drying equipment for drying each coating layer is not particularly limited, and known equipment can be used. Examples of the drying equipment include a hot air dryer, an infrared dryer, a gas burner, and a hot plate.

In the method for producing the gas barrier laminate of the present embodiment, since the coating liquid for forming the water vapor barrier layer contains the layered inorganic compound, the cationic resin and the anionic binder, the layered inorganic compound in the water vapor barrier layer Does not form a card house structure and is laminated in a uniformly dispersed state. Therefore, the formed water vapor barrier layer is excellent in water vapor barrier property. Further, in the step of forming the water vapor barrier layer, the surface of the water vapor barrier layer is formed smoothly, so that the gas barrier layer on the surface can also be formed uniformly. As a result, a gas barrier laminate having excellent gas barrier properties is formed.

The features of the present invention will be described in more detail below with reference to Examples and Comparative Examples. The materials, amounts used, ratios, treatment contents, treatment procedures, etc. shown in the following examples can be appropriately changed as long as they do not deviate from the gist of the present invention. Therefore, the scope of the present invention should not be construed as limited by the specific examples shown below.

<Example 1>
A layered inorganic compound (engineered kaolin, average length 10 μm, aspect ratio about 100, thickness about 100 nm, product name: Varisurf HX, manufactured by Imeris) is dispersed in water, and the content of the layered inorganic compound is 55% by mass. A dispersion was obtained (aqueous dispersion A). Self-emulsifying emulsion of ethylene / acrylic acid copolymer (solid content concentration 29.2% by mass, product name: Zyxen AC, manufactured by Sumitomo Seika) 55% by mass of aqueous dispersion A36 with respect to 34.2 parts by mass .4 parts by mass was added with stirring (dispersion liquid B). To this dispersion B, 0.75 parts by mass of a modified polyamide resin (solid content concentration 53% by mass, surface charge 0.35meq / g, product name: SPI203 (50) H, manufactured by Taoka Chemical Industry Co., Ltd.) is added, and the mixture is further stirred. bottom. Further, 0.30 parts by mass of a 25% by mass aqueous ammonia solution was added to the dispersion liquid B and stirred. Further, diluted water was added to the dispersion liquid B to adjust the solid content concentration to 40% by mass to prepare a coating material for a water vapor barrier layer.
Urethane emulsion A (solid concentration 30 wt%, the glass transition temperature of 130 ° C., 25 [mu] m thick sheet formed when oxygen permeability ^{2.0mL / (m 2 · day ·} atm), product name: Takelac WPB-341, Mitsui Chemicals (Manufactured) was added with diluted water so that the solid content concentration was 20% by mass to prepare a paint for the gas barrier layer. The urethane resin of the urethane emulsion A had a solubility in water at 25 ° C. of 10 g / L or less. Further, when 1H-NMR measurement was performed on the urethane emulsion A, 50 mol% or more of the constituent units derived from metaxylylene diisocyanate was contained with respect to the constituent units derived from polyisocyanate.
The resulting water vapor barrier layer coating, as the coating amount of the water vapor barrier layer is 12.0 g / ^{m 2,} bleached kraft paper (Oji Materia Corp., basis weight 50 g / ^{m 2,} a thickness of 66 .mu.m, the density 0.76 g / m ³ , Oji-type smoothness of one side 63 seconds, Wang-ken type smoothness of the other side 45 seconds, kraft size degree 15 seconds) Wang-ken type smoothness 63 seconds on the surface Was painted using a Mayer bar. Then, the bleached kraft paper coated with the water vapor barrier layer paint was dried at 120 ° C. for 1 minute in a hot air dryer. Further, the gas barrier layer paint is applied onto the water vapor barrier layer ^{with a Mayer bar so that the coating amount of the gas barrier layer is 3.0 g / m 2,} and then dried in a hot air dryer at 120 ° C. for 1 minute. , A gas barrier laminate was obtained.

<Example 2>
Urethane emulsion A (solid) in a layered inorganic compound (engineered kaolin, average length 10 μm, aspect ratio about 100, thickness about 100 nm, product name: Varisurf HX, manufactured by Imeris) in an aqueous dispersion with a solid content concentration of 50% by mass. min concentration 30 mass%, the glass transition temperature of 130 ° C., ^/ 25 [mu] m thick sheet formed when oxygen permeability 2.0mL (m 2 · day · atm ), product name: Takelac WPB-341, manufactured by Mitsui Chemicals) a solids The mixture was added so that the mass ratio (layered inorganic compound: urethane resin) was 1: 1 and stirred. Further, diluted water was added so that the solid content concentration became 20% by mass to prepare a coating material for the gas barrier layer. A gas barrier laminate was obtained in the same manner as in Example 1 except that the paint for the gas barrier layer was used.

<Example 3>
Diluted water was added to a vinylidene chloride emulsion (vinylidene chloride copolymer latex, solid content concentration 48.0% by mass, product name: Saran Latex L549B, manufactured by Asahi Kasei) so that the solid content concentration was 10% by mass, and a gas barrier was added. It was used as a layer of paint. A gas barrier laminate was obtained in the same manner as in Example 1 except that the paint for the gas barrier layer was used. The vinylidene chloride-based resin of the above-mentioned vinylidene chloride-based emulsion had a solubility of 10 g / L or less in water at 25 ° C.

<Comparative example 1>
Prepare a solution of ethylene-modified polyvinyl alcohol (PVA) (completely saponified type, product name: Excelval AQ-410, solid content concentration 15% by mass, manufactured by Kuraray) with a solid content concentration of 15% by mass, add diluted water, and solidify. The concentration was 10% by mass, and the paint was used as a gas barrier layer paint. A gas barrier laminate was obtained in the same manner as in Example 1 except that the paint for the gas barrier layer was used.

<Example 4>
Aqueous dispersion of layered inorganic compound (swellable mica, average length 6.3 μm, aspect ratio about 1000, thickness about 5 nm, solid content concentration 6% by mass, product name: NTO-05, manufactured by Topy Industries) 30.0 A self-emulsifying emulsion of an ethylene / acrylic acid copolymer (solid content concentration: 29.2% by mass, product name: Zyxen AC, manufactured by Sumitomo Seika) was added to the parts by mass with stirring, and the mixture was stirred. .. To this, 2.55 parts by mass of a modified polyamide resin (solid content concentration 53% by mass, product name: SPI203 (50) H, manufactured by Taoka Chemical Industry Co., Ltd.) was added, and the mixture was stirred. Further, 0.30 parts by mass of a 25% by mass aqueous ammonia solution was added and stirred. Further, diluted water was added to adjust the solid content concentration to 19% by mass to prepare a coating material for a water vapor barrier layer.
Urethane emulsion A (solid concentration 30 wt%, the glass transition temperature of 130 ° C., 25 [mu] m thick sheet formed when oxygen permeability ^{2.0mL / (m 2 · day ·} atm), product name: Takelac WPB-341, Mitsui Chemicals (Manufactured) was added with diluted water so that the solid content concentration was 20% by mass to prepare a paint for the gas barrier layer.
The resulting water vapor barrier layer coating, as the coating amount of the water vapor barrier layer is 6.0 g / ^{m 2,} bleached kraft paper (Oji Materia Corp., basis weight 50 g / ^{m 2,} a thickness of 66 .mu.m, the density 0.76 g / m ³ , Oji-type smoothness of one side 63 seconds, Wang-ken type smoothness of the other side 45 seconds, kraft size degree 15 seconds) Wang-ken type smoothness 63 seconds on the surface Was painted using a Mayer bar. Then, the bleached kraft paper coated with the water vapor barrier layer paint was dried at 120 ° C. for 1 minute in a hot air dryer. Further, the gas barrier layer paint is applied to the upper layer of the water vapor barrier layer ^{with a Mayer bar so that the coating amount of the gas barrier layer is 3.0 g / m 2,} and then dried in a hot air dryer at 120 ° C. for 1 minute. , A gas barrier laminate was obtained.

<Example 5>
A layered inorganic compound aqueous dispersion (swelling mica, average length 6.3 μm, aspect ratio about 1000, thickness about 5 nm, solid content concentration 6% by mass, product name: NTO-05, manufactured by Topy Industries), urethane system emulsion A (solid concentration 30 wt%, the glass transition temperature of 130 ° C., 25 [mu] m thick sheet formed when oxygen permeability ^{2.0mL / (m 2 · day ·} atm), product name: Takelac WPB-341, manufactured by Mitsui Chemicals ) Was added so that the mass ratio of the solid content (layered inorganic compound: urethane resin) was 1:10, and the mixture was stirred. Further, diluted water was added so that the solid content concentration became 20% by mass to prepare a coating material for the gas barrier layer. A gas barrier laminate was obtained in the same manner as in Example 4 except that the paint for the gas barrier layer was used.

<Example 6>
Urethane emulsion A (solid concentration 30 wt%, the glass transition temperature of 130 ° C., 25 [mu] m thick sheet formed when oxygen permeability ^{2.0mL / (m 2 · day ·} atm), product name: Takelac WPB-341, Mitsui Chemicals (Manufactured by) 33.3 parts by mass, aqueous dispersion of the first layered inorganic compound (swellable mica, average length 6.3 μm, aspect ratio about 1000, thickness about 5 nm, solid content concentration 6% by mass, product name : NTO-05, manufactured by Topy Industries) was added in an amount of 16.7 parts by mass. In addition, an aqueous dispersion of a second layered inorganic compound (engineered kaolin, average length 0.89 μm, aspect ratio about 33, thickness about 30 nm, solid content concentration 50% by mass, product name: Konzer Extreme, Imeris Manufactured) was added in an amount of 6 parts by mass, and the mixture was stirred. Further, diluted water was added to adjust the solid content concentration to 10% by mass to prepare a coating material for the gas barrier layer. A gas barrier laminate was obtained in the same manner as in Example 4 except that the paint for the gas barrier layer was used.

<Example 7>
Instead of bleached kraft paper, single glossy paper (manufactured by Oji Materia Co., Ltd., basis weight 50 g / m ² , thickness 62 μm, density 0.81 g / m ³ , Oji Materia smoothness 427 seconds on one side, other side A gas barrier laminate was obtained in the same manner as in Example 6 except that the Oken-type smoothness of 17 seconds) was used. The water vapor barrier layer paint was applied on a single-gloss paper with a smoothness of 17 seconds.

<Example 8>
Diluted water was added to a vinylidene chloride emulsion (vinylidene chloride copolymer latex, solid content concentration 48.0% by mass, product name: Saran Latex L549B, manufactured by Asahi Kasei) so that the solid content concentration was 10% by mass, and a gas barrier was added. It was used as a layer of paint. A gas barrier laminate was obtained in the same manner as in Example 4 except that the paint for the gas barrier layer was used.

<Example 9>
Urethane emulsion B having a hydroxy group (manufactured by Dainichi Seika Co., Ltd., HPU W-003, hydroxyl value 235 mgKOH / g, solid content concentration 30%, glass transition temperature 70 ° C., oxygen permeability at the time of forming a 25 μm thick sheet 1.6 mL ^{/ (m 2 · day · atm} )) in the dilution water to a solid concentration of 10 wt% was added to obtain a coating of the gas barrier layer. A gas barrier laminate was obtained in the same manner as in Example 4 except that the paint for the gas barrier layer was used.

<Example 10>
Instead of bleached kraft paper, single-gloss paper (manufactured by Oji F-Tex Co., Ltd., basis weight 50 g / m ² , thickness 63 μm, density 0.80 g / m ³ , Oken-style smoothness on one side 416 seconds, the other A gas barrier laminate was obtained in the same manner as in Example 9 except that the surface had a smoothness of 16 seconds). The water vapor barrier layer paint was applied on a single-gloss paper with a smoothness of 17 seconds.

<Example 11>
Urethane emulsion B having a hydroxy group (manufactured by Dainichi Seika Co., Ltd., HPU W-003, hydroxyl value 235 mgKOH / g, solid content concentration 30%, glass transition temperature 70 ° C., oxygen permeability at the time of forming a 25 μm thick sheet 1.6 mL ^{/ (m 2 · day · atm} )) 33.3 parts by weight, aqueous dispersion of the first layered inorganic compound (swelling mica, average length 6.3 [mu] m, an aspect ratio of about 1000, a thickness of about 5 nm, solid 33.3 parts by mass of a component concentration of 6% by mass, product name: NTO-05, manufactured by Topy Industries) was added. In addition, an aqueous dispersion of a second layered inorganic compound (engineered kaolin, average length 0.89 μm, aspect ratio about 33, thickness about 30 nm, solid content concentration 50% by mass, product name: Konzer Extreme, Imeris Manufactured) was added in an amount of 6 parts by mass, and the mixture was stirred. Further, diluted water was added to adjust the solid content concentration to 10% by mass to prepare a coating material for the gas barrier layer. A gas barrier laminate was obtained in the same manner as in Example 10 except that the paint for the gas barrier layer was used.

<Comparative example 2>
An aqueous solution of ethylene-modified polyvinyl alcohol (completely saponified type, product name: Excelval AQ-4104, manufactured by Kuraray) having a solid content concentration of 15% by mass was prepared, and diluted water was added thereto to obtain a solid content concentration of 10% by mass, and the gas barrier layer was prepared. It was used as the paint. A gas barrier laminate was obtained in the same manner as in Example 4 except that the gas barrier layer was the above.

(Evaluation method)
(1) Moisture vapor transmission rate The water vapor transmission rate of the gas barrier laminates obtained in Examples and Comparative Examples was JIS Z 0208: 1976 (cup method) B method (40 ° C ± 0.5 ° C, relative humidity 90% ± 2). %), And the measurement was performed with the gas barrier layer inside.

(2) Oxygen permeability The oxygen permeability of the gas barrier laminates obtained in Examples and Comparative Examples was 23 ° C. and a relative humidity of 50 using an oxygen permeability measuring device (OX-TRAN2 / 20 manufactured by MOCON). It was measured under the condition of%.
The oxygen permeability of the gas barrier laminate under high humidity conditions was similarly measured under the conditions of 23 ° C. and 85% relative humidity.
The oxygen permeability ratio was calculated using the following formula.
Oxygen permeability ratio = 23 ° C, oxygen permeability at relative humidity 85% (cc / m ² · day · atm) / 23 ° C, oxygen permeability at relative humidity 50% (cc / m ² · day · atm)

(3) Contact angle The contact angle on the surface of the gas barrier layer of the gas barrier laminates obtained in Examples and Comparative Examples was measured. Specifically, 4 μl of water was dropped on the surface of the gas barrier layer of the gas barrier laminate, and the contact angle 60 seconds after the dropping was measured using a dynamic contact angle measuring device DAT1100 manufactured by Matsubo Co., Ltd.

(4) Water resistance The water resistance of the gas barrier laminates obtained in Examples and Comparative Examples was obtained by dropping 1 mL of water at 60 ° C. on the gas barrier layer of the gas barrier laminate, holding it for 1 minute, and then wiping off the water. The condition of the coated surface of the gas barrier layer was evaluated visually and by touching it.
〇: No stickiness or dissolution of the gas barrier layer of the gas barrier laminate ×: Stickiness or dissolution of the gas barrier layer of the gas barrier laminate

(5) Heat-sealing property A set of gas-barrier laminated bodies are laminated so that the gas barrier layers face each other, and heat-sealed and laminated under the conditions of ^{160 ° C., 2.0 kgf / cm 2, 1 second using a heat press tester.} The body was made. This laminate was cut to prepare a rectangular measurement sample having a width of 15 mm and a length of 100 mm. When preparing the measurement sample, a non-heat-sealed portion was formed at the end portion in order to grasp the measurement sample by hand and peel the measurement sample. Then, the peeling state when the end portion that was not heat-sealed was held by hand and pulled was evaluated according to the following criteria.
〇: There is resistance when the end part that is not heat-sealed is held by hand and pulled, and one set of gas barrier laminates does not peel off from the other gas barrier laminate.
X: The end portion that is not heat-sealed is held by hand, there is no resistance when pulled, and one set of gas barrier laminates is easily peeled off from the other gas barrier laminate.

Urethane A: Urethane resin containing a structural unit derived from metaxylylene diisocyanate (Takelac WPB-341)
Urethane B: Hydroxy group-containing urethane resin (HPU W-003)

Compared with the comparative example, in the example, the oxygen permeability under high humidity conditions was suppressed. Further, in the examples, a gas barrier laminate having a large water contact angle was obtained, and the water repellency was excellent. Further, in the examples, a gas barrier laminate having excellent water resistance was obtained. Furthermore, by incorporating the layered inorganic compound in the gas barrier layer, 50% RH oxygen permeability was further suppressed. In addition, by incorporating two types of layered inorganic compounds having different aspect ratios in the gas barrier layer, the oxygen permeability ratio became smaller (the humidity dependence of oxygen permeability was suppressed to be smaller).

The gas barrier laminates obtained in Examples 3 and 8 to 11 in which a hydroxy group-containing urethane resin or a vinylidene chloride resin was used for the gas barrier layer were also excellent in heat sealability.

10 Paper support 20 Water vapor barrier layer 30 Gas barrier layer 100 Gas barrier laminate

Claims (17)

1. A gas-barrier laminate having a water vapor barrier layer and a gas barrier layer in this order on at least one surface of the paper support.
   The water vapor barrier layer contains a layered inorganic compound, a cationic resin and an anionic binder.
   A gas barrier laminate in which the gas barrier layer contains a water-suspendable polymer.
2. The gas barrier laminate according to claim 1, wherein the water-suspendable polymer is at least one selected from a urethane resin and a vinylidene chloride resin.
3. The gas barrier laminate according to claim 2, wherein the water-suspendable polymer is derived from a polymer dispersed in an emulsion, and the gas barrier layer is a coating layer of the emulsion.
4. The water-suspendable polymer is a urethane-based resin and is
   Any of claims 1 to 3, wherein when a sheet having a thickness of 25 μm is formed from the urethane resin, the oxygen permeability of the sheet at 23 ° C. and 50% relative humidity is 100 mL / (m ² · day · atm) or less. The gas barrier laminate according to item 1.
5. The water-suspendable polymer is a urethane-based resin and is
   The urethane resin contains at least one selected from the group consisting of a structural unit derived from metaxylylene diisocyanate and a structural unit derived from hydrogenated metaxylylene diisocyanate, according to any one of claims 1 to 4. The gas barrier laminate according to the description.
6. Claimed that the total number of the constituent units derived from the metaxylylene diisocyanate and the constituent units derived from the hydrogenated metaxylylene diisocyanate is 50% or more with respect to the number of constituent units derived from the polyisocyanate in the urethane resin. Item 5. The gas barrier laminate according to Item 5.
7. The water-suspendable polymer is a urethane-based resin and is
   The gas barrier laminate according to any one of claims 1 to 6, wherein the urethane resin has a hydroxy group and has a hydroxyl value of 50 mgKOH / g or more.
8. The gas barrier laminate according to any one of claims 1 to 7, wherein the gas barrier layer further contains a layered inorganic compound.
9. The gas barrier laminate according to claim 8, wherein the layered inorganic compound contained in the gas barrier layer has an aspect ratio of 20 or more and a thickness of 200 nm or less.
10. The gas barrier laminate according to claim 8 or 9, wherein the layered inorganic compound contained in the gas barrier layer is at least one selected from the group consisting of mica, bentonite and kaolin.
11. The gas barrier laminate according to any one of claims 1 to 10, wherein the layered inorganic compound contained in the water vapor barrier layer has an aspect ratio of 20 or more and a thickness of 200 nm or less.
12. The gas barrier laminate according to any one of claims 1 to 11, wherein the layered inorganic compound contained in the water vapor barrier layer is at least one selected from the group consisting of mica, bentonite and kaolin.
13. Claims 1 to 12, wherein the anionic binder is at least one selected from the group consisting of a styrene-butadiene copolymer, a styrene-acrylic copolymer and an olefin / unsaturated carboxylic acid copolymer. The gas barrier laminate according to any one item.
14. The gas barrier laminate according to any one of claims 1 to 13, wherein the cationic resin has a surface charge of 0.1 to 10 meq / g.
15. The gas barrier laminate according to any one of claims 1 to 14, further comprising a sealant layer in at least one outermost layer.
16. The gas barrier laminate according to claim 15, wherein the sealant layer contains a biodegradable resin.
17. The gas barrier laminate according to any one of claims 1 to 16, which is a packaging material.

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