JP5155142B2 - Paper container - Google Patents

Description

  The present invention relates to a paper container excellent in gas barrier properties.

  A laminate in which low-density polyethylene having thermal adhesiveness and water resistance is laminated on a paper layer is used for manufacturing a paper container. When retort sterilization is performed, instead of low-density polyethylene, heat-resistant polyolefin with high heat resistance and heat adhesion (for example, linear low-density polyethylene resin, high-density polyethylene resin, and polypropylene resin) Is used.

  When gas barrier properties are required for paper containers, the gas barrier layer includes aluminum foil, aluminum oxide coating, silica coating, metallized stretched polyester, metallized stretched polypropylene, ethylene / vinyl alcohol copolymer, polyvinyl alcohol. A laminated material is described in Patent Document 1.

  However, in a laminate using an ethylene / vinyl alcohol copolymer, polyvinyl alcohol or the like as a gas barrier layer, the gas barrier property is lowered in a wet state, so that it is sufficient when a hot water treatment such as a retort treatment is performed. There is a tendency that gas barrier properties are not exhibited.

  In addition, the aluminum foil layer, the aluminum oxide coating layer, the silica coating layer, the metallized stretched polyester layer, and the metallized stretched polypropylene layer do not have sufficient bending resistance to bending. Therefore, a laminate using these layers as a gas barrier layer has a problem in that pinholes are easily generated in a manufacturing process of a paper container and gas barrier properties are easily impaired.

  In order to deal with the above problem, the present inventors have proposed a paper container having a high oxygen barrier property (Patent Document 2). Patent Document 3 discloses that by appropriately reducing the thickness of the gas barrier layer, cracks due to bending or the like during use are less likely to occur, and high oxygen barrier properties are maintained.

Japanese National Patent Publication No. 11-508502 JP 2006-297925 A JP 2002-46208 A

  However, there is an increasing demand for further extension of the quality retention period for the purpose of increasing the added value of products. In order to meet the demand, it is necessary to enhance the durability of the gas barrier layer against bending and the like.

  Also about the paper container of the said patent document 2, it is anticipated that the durability of a gas barrier layer with respect to bending can be improved by making a gas barrier layer thin. However, in the paper container described in Patent Document 2, when the gas barrier layer is thinned, the oxygen barrier property may decrease exponentially. Further, there is a demand for further improving the oxygen barrier property after the production of the container.

  As an example of a paper container, there is a paper container having a window for viewing contents. By forming the window, the storage state of the contents can be confirmed, and the purchase intention of the purchaser can be promoted. The window layer has the paper layer removed, and the contents can be seen through the gas barrier layer. Therefore, in the paper container with a window, the transparency of the gas barrier layer is important. However, in the paper container described in Patent Document 2, when the retort process is performed under severe conditions, the appearance may be deteriorated.

  In such a situation, an object of the present invention is to provide a paper container that has little deterioration in oxygen barrier properties even after performing a bending process or a retort process and that has a good appearance even after the retort process.

  As a result of intensive studies to achieve the above object, the present inventors have found that the above object can be achieved by using a specific gas barrier laminate. The present invention is based on this new finding.

  The paper container of the present invention is a paper container formed using a gas barrier laminate. The gas barrier laminate includes a paper layer and at least one gas barrier property layer laminated on the paper layer. The layer having the gas barrier property includes a hydrolysis condensate of at least one compound (L) containing a hydrolyzable characteristic group, and at least one functional group selected from a carboxyl group and a carboxylic anhydride group. It consists of a composition containing polymer (X) to contain. The compound (L) includes at least one compound (A) containing a metal atom to which a hydrolyzable characteristic group is bonded. At least a part of —COO— group contained in the functional group of the polymer (X) is neutralized and / or reacted with a compound (P) containing two or more amino groups. At least a part of the —COO— group contained in the functional group of the polymer (X) is neutralized with a divalent or higher valent metal ion. In the composition, a ratio of [equivalent of amino group contained in the compound (P)] / [equivalent of -COO-group contained in the functional group of the polymer (X)] is 0.2 / 100 to It is in the range of 20.0 / 100.

  The paper container of the present invention has little decrease in oxygen barrier properties even when bending or retorting is performed. Moreover, since the transparency of the gas barrier layer is good even after the retort treatment, it is preferably used for a container with a window.

  Embodiments of the present invention will be described below. In the following description, a specific compound may be exemplified as a substance that exhibits a specific function, but the present invention is not limited to this. In addition, the materials exemplified may be used alone or in combination unless otherwise specified.

[Paper container]
The paper container of the present invention is formed using a specific laminate (hereinafter sometimes referred to as “gas barrier laminate”). That is, the paper container of the present invention includes a gas barrier laminate. Note that all of the paper containers may be formed using a gas barrier laminate, or a part thereof may be formed of a material other than the gas barrier laminate. For example, the gas barrier laminate is used for 50% or more, 60% or more, 70% or more, 80% or more, 90% or more, or 100% of the area when the paper container is developed.

  The gas barrier laminate includes a paper layer and at least one gas barrier property layer (hereinafter sometimes referred to as “gas barrier layer”) laminated on the paper layer.

  The kind of the paper container of the present invention is not particularly limited. The paper container of the present invention may be, for example, a single board type gobber top type, brick (brick) type, rectangular parallelepiped type, or conical type paper container. The paper container of the present invention may be a cup type paper container, a spiral type paper container, or an insert molding type paper container.

  The base material of the gas barrier laminate may be a paper layer. Alternatively, the gas barrier laminate may include a substrate on which the gas barrier layer is laminated separately from the paper layer. In that case, the gas barrier laminate includes a paper layer, a base material, and at least one gas barrier layer laminated on the base material. In that case, a base material and a gas barrier layer are laminated | stacked on a paper layer.

[Paper layer]
The paper layer constituting the gas barrier laminate is a layer that maintains shape retention. For the paper layer, for example, white paperboard, Manila ball, milk carton base paper, cup base paper, ivory paper, etc. can be used.

[Heat-resistant polyolefin layer]
The gas barrier laminate may include a heat resistant polyolefin layer. Examples of the resin used for the heat resistant polyolefin layer include a linear low density polyethylene resin, a high density polyethylene resin, and a polypropylene resin. The melting point of the heat-resistant polyolefin layer is 100 ° C. or higher, preferably 120 ° C. or higher, more preferably 130 ° C. or higher. Polypropylene is preferable because of its high heat resistance. Polypropylene may be a homopolymer of polypropylene, a random copolymer or a block copolymer obtained by copolymerizing propylene and one or more other monomers, or one or more other monomers in polypropylene. It may be a graft polymerized polymer. Further, the stereoregularity of polypropylene is not limited, and any of isotactic, atactic, syndiotactic and the like may be used.

  Monomers that may be copolymerized with propylene include ethylene, 1-butene, 1-pentane, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, 3-methyl- Examples include 1-butene, 3-methyl-1-pentene, 4-methyl-1-pentene, 2,2,4-trimethylpentene, and the like.

  Monomers that may be graft polymerized to polypropylene include acrylic acid, methacrylic acid, glycidyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, diethyl maleate, monoethyl maleate, di-n maleate -Butyl, maleic acid, maleic anhydride, fumaric acid, itaconic acid, itaconic anhydride, 5-norbornene-2,3-anhydride, citraconic acid, citraconic anhydride, crotonic acid, crotonic acid anhydride, acrylonitrile Methacrylonitrile, sodium acrylate, calcium acrylate, magnesium acrylate and the like.

  In the production of a gas barrier laminate, a heat-resistant polyolefin layer (for example, an unstretched heat-resistant polyolefin film or a stretched heat-resistant polyolefin film) and another film are combined with a known method (dry lamination method, wet lamination method, hot melt lamination). May be attached by a method, etc.). Moreover, you may form a heat resistant polyolefin layer on another film by the well-known T-die extrusion method etc. Moreover, you may arrange | position an adhesive layer between a heat resistant polyolefin layer and another layer as needed. The adhesive layer is formed using an anchor coat agent, an adhesive, an adhesive resin, or the like. The thickness of the heat-resistant polyolefin layer is preferably in the range of 10 μm to 200 μm, more preferably in the range of 20 μm to 150 μm, from the viewpoint of mechanical toughness, impact resistance, puncture resistance, and the like.

[Gas barrier layer]
The gas barrier layer is made of a specific composition. The composition consists of a composition containing the hydrolysis condensate of compound (L) and polymer (X). The compound (L) is at least one compound containing a hydrolyzable characteristic group, and is typically at least one compound containing a metal atom to which the hydrolyzable characteristic group is bonded. . The polymer (X) is a polymer containing at least one functional group selected from a carboxyl group and a carboxylic anhydride group. Hereinafter, at least one functional group selected from a carboxyl group and a carboxylic anhydride group contained in the polymer (X) may be referred to as “functional group (F)”. At least a part of —COO— group contained in the functional group (F) of the polymer (X) is neutralized and / or reacted with the compound (P) containing two or more amino groups. Further, at least a part of the —COO— group contained in the functional group (F) is neutralized with a divalent or higher metal ion. In other words, at least a part of the functional group constitutes a salt with a divalent or higher valent metal ion. In the composition, the ratio of [equivalent of amino group contained in compound (P)] / [equivalent of -COO- group contained in functional group of polymer (X)] is 0.2 / 100 to 20. It is in the range of 0/100. In addition, [equivalent of amino group contained in compound (P)] / [equivalent of -COO- group contained in functional group of polymer (X)] is "number of moles of amino group contained in compound (P)". ] / [Number of moles of —COO— group contained in the functional group of the polymer (X)].

  The gas barrier layer is laminated on at least one surface of the substrate. A gas barrier layer may be laminated | stacked only on the single side | surface of a base material, and may be laminated | stacked on both surfaces of a base material. The gas barrier laminate used in the present invention may include layers other than the gas barrier layer.

  The proportion of the hydrolyzed condensate of the compound (L) and the polymer (X) in the composition is, for example, 50% or more, 70% or more, 80% or more, 90% or more, 95% or more, or 98% by weight or more.

[Hydrolysis condensate]
The composition which comprises a gas barrier layer contains the hydrolysis-condensation product of a compound (L). By hydrolyzing the compound (L), at least a part of the characteristic group of the compound (L) is substituted with a hydroxyl group. Furthermore, the hydrolyzate condenses to form a compound in which metal atoms are bonded through oxygen. When this condensation is repeated, it becomes a compound that can be regarded as a metal oxide substantially. Here, in order for this hydrolysis and condensation to occur, it is important that the compound (L) contains a hydrolyzable characteristic group (functional group), and these groups are not bonded. , Hydrolysis and condensation reactions do not occur or are very slow. Therefore, in that case, it is difficult to obtain the effect of the present invention. Si may be classified as a metalloid element, but in this specification, Si is described as a metal.

  This hydrolysis-condensation product can be manufactured from a specific raw material using the method used by the well-known sol-gel method, for example. The raw materials include compound (L), compound (L) partially hydrolyzed, compound (L) completely hydrolyzed, compound (L) partially hydrolyzed / condensed, A compound in which the compound (L) is completely hydrolyzed and partly condensed, or a combination thereof is used. These raw materials may be produced by a known method, or commercially available ones may be used. Although there is no particular limitation, for example, a condensate obtained by hydrolysis and condensation of about 2 to 10 molecules can be used as a raw material. Specifically, for example, a material obtained by hydrolyzing and condensing tetramethoxysilane into a dimer to 10-mer linear condensate can be used as a raw material.

Examples of the characteristic group having hydrolyzability include groups exemplified as OR ¹ and X ^{1 in} the following formula (I).

The compound (L) includes at least one compound (A) including a metal atom to which a hydrolyzable characteristic group is bonded. A typical compound (A) is at least one compound represented by the following formula (I).
M ¹ (OR ¹ ) _q R ² _pqr X ¹ _r (I)
[In Formula (I), M ¹ represents Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La, or Nd. R ¹ represents an alkyl group. R ² represents an alkyl group, an aralkyl group, an aryl group or an alkenyl group. X ¹ represents a halogen atom. p is equal to the valence of M ¹ . q represents an integer of 0 to p. r represents an integer of 0 to p. 1 ≦ q + r ≦ p. ]

In the formula, M ¹ represents an atom selected from Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La, and Nd. Of these, Si, Al, Ti or Zr is preferable, and Si, Al or Ti is particularly preferable. Examples of the alkyl group represented by R ¹ include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a t-butyl group, and the like, preferably a methyl group or an ethyl group. is there. Examples of the halogen atom represented by X ² include a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable. Examples of the alkyl group represented by R ² include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, a t-butyl group, and an n-octyl group. Examples include benzyl group, phenethyl group, and trityl group. In addition, examples of the aryl group represented by R ² include a phenyl group, a naphthyl group, a tolyl group, a xylyl group, and a mesityl group. Examples of the alkenyl group include a vinyl group and an allyl group.

  Specific examples of the compound represented by the formula (I) include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, octyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxysilane, vinyltrimethoxysilane. Silane alkoxides such as ethoxysilane, chlorotrimethoxysilane, chlorotriethoxysilane, dichlorodimethoxysilane, dichlorodiethoxysilane, trichloromethoxysilane, and trichloroethoxysilane; halogenated silanes such as vinyltrichlorosilane, tetrachlorosilane, and tetrabromosilane; Alkoxy titanium compounds such as titanium tetramethoxide, titanium tetraethoxide, titanium tetraisopropoxide, titanium methyltriisopropoxide; Titanium genide; alkoxyaluminum compounds such as aluminum trimethoxide, aluminum triethoxide, aluminum triisopropoxide, aluminum methyldiisopropoxide, aluminum tributoxide, diethoxyaluminum chloride; zirconium tetraethoxide, zirconium tetraisopropoxy And alkoxyzirconium compounds such as zirconium methyltriisopropoxide. Preferred examples of the compound (A) represented by the formula (I) include tetramethoxysilane and tetraethoxysilane.

Compound (L) comprises at least one compound (B) containing a metal atom in which a hydrolyzable characteristic group and an alkyl group substituted with a functional group having reactivity with a carboxyl group are bonded. May be included. A typical compound (B) is at least one compound represented by the following formula (II). By containing the compound (B), changes such as oxygen barrier properties and transparency of the gas barrier laminate before and after the boil treatment and before and after the retort treatment are further reduced.
M ² (OR ³ ) _n X ² _k Z ² _mnk (II)
[In Formula (II), M ² represents Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La, or Nd. R ³ represents an alkyl group. X ² represents a halogen atom. Z ² represents an alkyl group substituted with a functional group having reactivity with a carboxyl group. m is equal to the valence of M ² . n represents an integer of 0 to (m-1). k represents an integer of 0 to (m−1). 1 ≦ n + k ≦ (m−1). ]

In formula (II), M ² is selected from Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La and Nd. Represents an atom. M ² is preferably Si, Al, Ti or Zr, and particularly preferably Si. Examples of the alkyl group represented by R ³ include a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, and a t-butyl group, preferably a methyl group or an ethyl group. is there. Examples of the halogen atom represented by X ² include a chlorine atom, a bromine atom, and an iodine atom, and a chlorine atom is preferable. Examples of the functional group having reactivity with a carboxyl group that Z ² has include an epoxy group, an amino group, a hydroxyl group, a halogen atom, a mercapto group, an isocyanate group, a ureido group, an oxazoline group, or a carbodiimide group. An epoxy group, an amino group, an isocyanate group, a ureido group or a halogen atom is preferred, and for example, at least one selected from an epoxy group, an amino group and an isocyanate group is more preferred. Examples of the alkyl group substituted with such a functional group include those exemplified for R ³ .

  Specific examples of the compound represented by the formula (II) include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrichlorosilane, γ-aminopropyltrisilane. Methoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrichlorosilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-chloropropyltrichlorosilane, γ-bromopropyltrimethoxysilane, γ -Bromopropyltriethoxysilane, γ-bromopropyltrichlorosilane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropyltriethoxysilane, γ-mercaptopropyltrichlorosilane, γ-isocyanatopropyltrimethoxysilane, γ Isocyanatopropyltriethoxysilane, .gamma. isocyanate propyl trichlorosilane, .gamma.-ureidopropyltrimethoxysilane, .gamma.-ureidopropyltriethoxysilane, and the like .gamma. ureidopropyltrimethoxysilane trichlorosilane. Preferred examples of the compound represented by the formula (II) include γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-chloropropyltriethoxysilane, γ-aminopropyltrimethoxysilane and γ-aminopropyltriethoxysilane.

In the case where the compound (L) includes at least one compound (A) represented by the above formula (I) and at least one compound (B) represented by the above formula (II), The ratio of [number of moles of M ¹ atom derived from the compound represented by formula (I)] / [number of moles of M ² atom derived from the compound represented by formula (II)] was 99.5 / 0. It is preferable that it exists in the range of 5-80.0 / 20.0. When this ratio is larger than 99.5 / 0.5, the hot water resistance of the gas barrier laminate may be lowered. Moreover, when this ratio becomes smaller than 80.0 / 20.0, the gas barrier property of the gas barrier laminate may be deteriorated. This ratio is more preferably in the range of 98.0 / 2.0 to 89.9 / 10.1.

In addition, [the number of moles of M ¹ atom derived from the compound represented by formula (I)] is substantially the same as the [number of moles of the compound represented by formula (I)] used for generating the hydrolysis condensate. Equally, [the number of moles of M ² atom derived from the compound represented by the formula (II)] is substantially equal to the [number of moles of the compound represented by the formula (II)] used for the production of the hydrolysis condensate. be equivalent to. Therefore, in the following description, the ratio may be replaced with [number of moles of compound represented by formula (I)] / [number of moles of compound represented by formula (II)].

  Ratio of the compound represented by formula (I) and the compound represented by formula (II) in the compound (L) (in the case where the compound represented by formula (II) is not included, in the formula (I) The proportion of the compound represented) is, for example, 80 mol% or more, 90 mol% or more, 95 mol% or more, 95 mol% or more, 98 mol% or more, 99 mol% or more, or 100 mol%.

  The number of molecules condensed in the hydrolysis condensate of the compound (L) can be controlled by the amount of water, the type and concentration of the catalyst used at the time of hydrolysis / condensation, the temperature at which the hydrolysis condensation is performed, and the like.

  In the composition constituting the gas barrier layer, [weight of inorganic component derived from compound (L)] / [weight of organic component derived from compound (L) from the viewpoint of better gas barrier properties of the gas barrier laminate. And the sum of the weight of the organic component derived from the polymer (X)] is preferably in the range of 20.0 / 80.0 to 80.0 / 20.0. 30.0 / 70.0 More preferably, it is in the range of ˜69.9 / 30.1.

  The weight of the inorganic component derived from the compound (L) can be calculated from the weight of the raw material used when preparing the composition. That is, compound (L), compound (L) partially hydrolyzed, compound (L) completely hydrolyzed, compound (L) partially hydrolyzed, compound (L) Assuming that the product is completely hydrolyzed and partly condensed, or a combination of these, is completely hydrolyzed and condensed into a metal oxide, and the weight of the metal oxide is calculated as compound (L). It is regarded as the weight of the inorganic component derived from.

More specifically describing the calculation of the weight of the metal oxide, when the compound (A) represented by the formula (I) does not contain R ² , when it is completely hydrolyzed and condensed, the composition formula is A compound represented by M ¹ O _{p / 2} is obtained. Further, when the compound (A) represented by the formula (I) contains R ² , when it is completely hydrolyzed and condensed, the composition formula is M ¹ O _{(q + r) / 2} R ² _{(pqr )} . Of this compound, the portion of M ¹ O _{(q + r) / 2} is a metal oxide. R ² is an organic component derived from the compound (L). Moreover, it calculates similarly about a compound (B). At this time, Z ² is an organic component derived from the compound (L).

  When the polymer (X) is neutralized by ions not containing metal ions (for example, ammonium ions), the weight of the ions (for example, ammonium ions) is also the weight of the organic component derived from the polymer (X). Added to.

[Compound (P)]
The compound (P) containing two or more amino groups is a compound different from the compound (L) and the polymer (X). Specific examples of the compound (P) include alkylene diamines, polyalkylene polyamines, alicyclic polyamines, aromatic polyamines, polyvinylamines, etc., and the gas barrier property of the gas barrier laminate is better. From the viewpoint of, alkylene diamine is preferable.

  Specific examples of the compound (P) include hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, 1,3-diaminocyclohexane, 1,2-diaminocyclohexane, 1,4-diaminocyclohexane. Xylylenediamine, chitosan, polyallylamine, polyvinylamine and the like. The compound (P) is preferably at least one selected from the group consisting of ethylenediamine, propylenediamine, and chitosan, for example, from the viewpoint that the gas barrier properties of the gas barrier laminate are improved. .

  In the composition constituting the gas barrier layer, the ratio of [equivalent of amino group contained in compound (P)] / [equivalent of -COO-group contained in functional group of polymer (X)] was 0.2 / It exists in the range of 100-20.0 / 100 (for example, the range of 0.2 / 100-19.4 / 100). In this range, the gas barrier laminate exhibits good gas barrier properties. When the ratio is smaller than 0.2 / 100, the hot water resistance of the gas barrier laminate is lowered, and the gas barrier property after retorting is lowered. On the other hand, when the ratio is larger than 20.0 / 100, the gas barrier properties before and after the retort treatment of the gas barrier laminate are deteriorated. The above ratio is preferably in the range of 1.0 / 100 to 4.9 / 100 for the reason described above.

[Compound (Q)]
The composition constituting the gas barrier layer may contain a compound (Q) containing two or more hydroxyl groups. According to this configuration, the gas barrier property after elongation of the gas barrier laminate is improved. More specifically, by adding the compound (Q), even if the gas barrier laminate is stretched, the gas barrier layer is less likely to be damaged, and as a result, the gas barrier layer retains high gas barrier properties even after being stretched. The gas barrier property of the gas barrier laminate is hardly lowered even in a state after elongation due to tension at the time of processing such as laminating or elongation when a paper container filled with food is dropped.

  Compound (Q) is a compound different from compound (L) and polymer (X). The compound (Q) includes a low molecular weight compound and a high molecular weight compound. Preferred examples of the compound (Q) include polyvinyl alcohol, partially saponified polyvinyl acetate, ethylene-vinyl alcohol copolymer, polyethylene glycol, polyhydroxyethyl (meth) acrylate, polysaccharides such as starch, and starches. Polymer compounds such as polysaccharide derivatives derived from saccharides are included.

[Carboxylic acid-containing polymer (polymer (X))]
The composition constituting the gas barrier layer includes a neutralized product of a polymer containing at least one functional group selected from a carboxyl group and a carboxylic anhydride group. Hereinafter, the polymer (polymer (X)) may be referred to as a “carboxylic acid-containing polymer”.

  The neutralized product of the carboxylic acid-containing polymer can be obtained by neutralizing at least a part of the —COO— group contained in the functional group of the carboxylic acid-containing polymer with a divalent or higher metal ion. The carboxylic acid-containing polymer has two or more carboxyl groups or one or more carboxylic anhydride groups in one polymer molecule. Specifically, a polymer containing two or more structural units having one or more carboxyl groups such as an acrylic acid unit, a methacrylic acid unit, a maleic acid unit, and an itaconic acid unit in one molecule of the polymer is used. it can. Moreover, the polymer containing the structural unit which has the structure of carboxylic anhydrides, such as a maleic anhydride unit and a phthalic anhydride unit, can also be used. One type or two types of structural units having one or more carboxyl groups and / or structural units having a structure of carboxylic anhydride (hereinafter, these may be collectively referred to as “carboxylic acid-containing units (G)”) The above may be contained in the carboxylic acid-containing polymer.

  Moreover, the gas barrier property laminated body with favorable gas barrier property is obtained by making the content rate of the carboxylic acid content unit (G) which occupies for all the structural units of a carboxylic acid containing polymer into 10 mol% or more. The content is more preferably 20 mol% or more, further preferably 40 mol% or more, and particularly preferably 70 mol% or more. In addition, when a carboxylic acid containing polymer contains both the structural unit which contains 1 or more of carboxyl groups, and the structural unit which has a structure of a carboxylic anhydride, the sum total of both should just be said range.

  Other structural units other than the carboxylic acid-containing unit (G) that may be contained in the carboxylic acid-containing polymer are not particularly limited, but are methyl acrylate units, methyl methacrylate units, ethyl acrylate units, methacrylic acid. Structural units derived from (meth) acrylic esters such as ethyl units, butyl acrylate units and butyl methacrylate units; structural units derived from vinyl esters such as vinyl formate units and vinyl acetate units; styrene units, One or more structural units selected from p-styrene sulfonic acid units; structural units derived from olefins such as ethylene units, propylene units, and isobutylene units. When the carboxylic acid-containing polymer contains two or more structural units, the carboxylic acid-containing polymer is in the form of an alternating copolymer, a random copolymer, a block copolymer, or a taper. It may be in the form of a type copolymer.

  Specific examples of the carboxylic acid-containing polymer include polyacrylic acid, polymethacrylic acid, and poly (acrylic acid / methacrylic acid). The carboxylic acid-containing polymer may be at least one polymer selected from polyacrylic acid and polymethacrylic acid. Specific examples in the case of containing other structural units other than the above-described carboxylic acid-containing unit (G) include ethylene-maleic anhydride copolymers, styrene-maleic anhydride copolymers, and isobutylene-maleic anhydride. Examples thereof include an alternating copolymer, an ethylene-acrylic acid copolymer, and a saponified ethylene-ethyl acrylate copolymer.

  The molecular weight of the carboxylic acid-containing polymer is not particularly limited, but the number average molecular weight is 5,000 or more from the viewpoint of excellent gas barrier properties of the resulting gas barrier laminate and excellent mechanical properties such as drop impact strength. Preferably, it is preferably 10,000 or more, and more preferably 20,000 or more. The upper limit of the number average molecular weight of the carboxylic acid-containing polymer is not particularly limited, but is generally 1,500,000 or less.

  Further, although the molecular weight distribution of the carboxylic acid-containing polymer is not particularly limited, from the viewpoint of improving the surface appearance such as haze of the gas barrier laminate and the storage stability of the solution (U) described later, The molecular weight distribution represented by the weight average molecular weight / number average molecular weight ratio of the carboxylic acid-containing polymer is preferably in the range of 1-6, more preferably in the range of 1-5, and in the range of 1-4. More preferably.

[Neutralization (ionization)]
The neutralized product of the carboxylic acid-containing polymer is a divalent or higher-valent metal having at least a part of at least one functional group (functional group (F)) selected from the carboxyl group and carboxylic anhydride group of the carboxylic acid-containing polymer. Obtained by neutralization with ions. In other words, this polymer contains a carboxyl group neutralized with a divalent or higher metal ion.

  It is important that the metal ion neutralizing the functional group (F) is divalent or higher. When the functional group (F)) is not neutralized or neutralized only by monovalent ions, a laminate having good gas barrier properties cannot be obtained. Specific examples of divalent or higher metal ions include calcium ions, magnesium ions, divalent iron ions, trivalent iron ions, zinc ions, divalent copper ions, lead ions, divalent mercury ions, barium ions, A nickel ion, a zirconium ion, an aluminum ion, a titanium ion, etc. can be mentioned. For example, the divalent or higher valent metal ion may be at least one ion selected from the group consisting of calcium ion, magnesium ion, barium ion, zinc ion, iron ion and aluminum ion.

  For example, 10 mol% or more (for example, 15 mol% or more) of the —COO— group contained in the functional group (F) of the carboxylic acid polymer is neutralized with a divalent metal ion or more. When the carboxyl group and / or carboxylic anhydride group in the carboxylic acid-containing polymer is neutralized with a metal ion having a valence of 2 or more, the gas barrier laminate used in the present invention exhibits good gas barrier properties.

  Note that the carboxylic anhydride group is considered to contain two —COO— groups. That is, when there are a moles of carboxyl groups and b moles of carboxylic anhydride groups, the total number of —COO— groups contained is (a + 2b) moles. The proportion of the -COO- group contained in the functional group (F) that is neutralized with a divalent or higher metal ion is preferably 60 mol% or more and 100 mol% or less, more preferably 70 mol% or more. More preferably, it is 80 mol% or more. By increasing the proportion of neutralization, higher gas barrier properties can be realized.

  The degree of neutralization (ionization degree) of the functional group (F) is determined by measuring the infrared absorption spectrum of the gas barrier laminate by the ATR method (total reflection measurement method) or scraping the gas barrier layer from the gas barrier laminate, The infrared absorption spectrum can be obtained by measuring by the KBr method. It can also be obtained from the value of the fluorescent X-ray intensity of the metal element used for ionization by fluorescent X-ray measurement.

The infrared absorption spectrum peak attributed to C = O stretching vibration of the carboxyl group or carboxylic anhydride group before the neutralization (ionization front) is observed in the range of 1600cm ^-1 ~1850cm ^-1, neutralization (ionization ), The C═O stretching vibration of the carboxyl group is observed in the range of 1500 cm ^{−1 to} 1600 cm ⁻¹ , so that both can be separated and evaluated in the infrared absorption spectrum. Specifically, the ratio is obtained from the maximum absorbance in each range, and the ionization degree of the polymer constituting the gas barrier layer in the gas barrier laminate can be calculated using a calibration curve prepared in advance. A calibration curve can be created by measuring infrared absorption spectra for a plurality of standard samples having different degrees of neutralization.

  When the film thickness of the gas barrier layer is 1 μm or less and the substrate contains an ester bond, the ester bond peak of the substrate is detected in the infrared absorption spectrum by the ATR method, and the carboxylic acid-containing polymer constituting the gas barrier layer Since it overlaps with the —COO— peak of (= polymer (X)), the degree of ionization cannot be determined accurately. Therefore, the ionization degree of the polymer (X) constituting the gas barrier layer having a film thickness of 1 μm or less is calculated based on the result of the fluorescent X-ray measurement.

  Specifically, the ionization degree of the polymer (X) constituting the gas barrier layer laminated on the substrate not containing an ester bond is measured by an infrared absorption spectrum. Next, the fluorescence X-ray intensity of the metal element used for ionization is determined by fluorescent X-ray measurement for the laminate in which the degree of ionization is measured. Then, the same measurement is implemented about the laminated body from which only an ionization degree differs. A correlation between the degree of ionization and the fluorescent X-ray intensity of the metal element used for ionization is obtained, and a calibration curve is created. And X-ray fluorescence measurement is performed about the gas-barrier laminated body using the base material containing an ester bond, and an ionization degree is calculated | required based on the said calibration curve from the fluorescence X-ray intensity of the metal element used for ionization.

  Further, the composition constituting the gas barrier layer may be carbonate, hydrochloride, nitrate, hydrogen carbonate, sulfate, hydrogen sulfate, phosphate, boric acid within the range not impairing the effects of the present invention. Salts, inorganic acid metal salts such as aluminate; organic acid metal salts such as oxalate, acetate, tartrate, stearate; acetylacetonate metal complexes such as aluminum acetylacetonate, titanocene, etc. Metal complexes such as cyclopentadienyl metal complexes and cyano metal complexes; layered clay compounds, crosslinking agents, plasticizers, antioxidants, ultraviolet absorbers, flame retardants and the like may be contained. The composition constituting the gas barrier layer may contain a metal oxide fine powder, a silica fine powder, and the like.

[Base material]
As the base material used in the gas barrier laminate, base materials made of various materials such as a thermoplastic resin film and a thermosetting resin film can be used. For example, a film having a predetermined shape made of a film such as a thermoplastic resin film or a thermosetting resin film; a fiber aggregate such as fabric or paper; wood; a metal oxide or the like can be used. Especially, a thermoplastic resin film is especially useful as a base material of the gas-barrier laminated body used for food packaging materials. The substrate may also include a paper layer. The base material may have a multilayer structure composed of a plurality of materials.

  Examples of the thermoplastic resin film include polyolefin resins such as polyethylene and polypropylene; polyester resins such as polyethylene terephthalate, polyethylene-2,6-naphthalate, polybutylene terephthalate and copolymers thereof; nylon 6, nylon 66, Polyamide resins such as nylon 12; polystyrene, poly (meth) acrylate, polyacrylonitrile, polyvinyl acetate, polycarbonate, polyarylate, regenerated cellulose, polyimide, polyetherimide, polysulfone, polyethersulfone, polyetheretherketone And a film obtained by molding an ionomer resin or the like. As the base material of the laminate used for the food packaging material, a film made of polyethylene, polypropylene, polyethylene terephthalate, nylon 6 or nylon 66 is preferable.

  The thermoplastic resin film may be a stretched film or an unstretched film. However, the thermoplastic resin film is excellent in processing suitability for printing, laminating and the like of the gas barrier laminate, so that it is particularly suitable for stretched films. An axially stretched film is preferred. The biaxially stretched film may be a biaxially stretched film produced by any of the simultaneous biaxial stretching method, the sequential biaxial stretching method, and the tubular stretching method.

  Further, the gas barrier laminate may further include an adhesive layer (H) disposed between the base material and the gas barrier layer. According to this structure, the adhesiveness of a base material and a gas barrier layer can be improved. The adhesive layer (H) made of an adhesive resin can be formed by treating the surface of the substrate with a known anchor coating agent or applying a known adhesive to the surface of the substrate. As a result of examining various adhesive resins, it is preferable that an adhesive resin containing a urethane bond and having a nitrogen atom (a nitrogen atom of the urethane bond) occupying the entire resin is in the range of 0.5 to 12% by weight. I found it. By using such an adhesive resin, the adhesion between the substrate and the gas barrier layer can be particularly enhanced. When the base material and the gas barrier layer are strongly bonded via the adhesive layer (H), the gas barrier property and the appearance are deteriorated when the gas barrier laminate used in the present invention is subjected to processing such as printing or lamination. Can be suppressed. The content of nitrogen atoms (nitrogen atoms of urethane bonds) contained in the adhesive resin is more preferably in the range of 2 to 11% by weight, and further preferably in the range of 3 to 8% by weight.

  As the adhesive resin containing a urethane bond, a two-component reaction type polyretane-based adhesive in which a polyisocyanate component and a polyol component are mixed and reacted is preferable.

  By increasing the thickness of the adhesive layer (H), the strength of the gas barrier laminate can be increased. However, when the adhesive layer (H) is too thick, the appearance deteriorates. The thickness of the adhesive layer (H) is preferably in the range of 0.03 μm to 0.18 μm. According to this configuration, when processing such as printing or laminating is performed on the gas barrier laminate used in the present invention, deterioration of the gas barrier property and appearance can be suppressed, and further, the gas barrier property used in the present invention. The drop strength of the packaging material using the laminate can be increased. The thickness of the adhesive layer (H) is more preferably in the range of 0.04 μm to 0.14 μm, and still more preferably in the range of 0.05 μm to 0.10 μm.

In the gas barrier laminate used in the present invention, the total thickness of the gas barrier layers contained in the laminate is preferably 1.0 μm or less, for example 0.9 μm or less. By reducing the thickness of the gas barrier layer, the dimensional change of the gas barrier laminate during processing such as printing and laminating can be suppressed low. Further, by making the gas barrier layer thin, the flexibility of the gas barrier laminate is increased, and the mechanical properties of the gas barrier laminate can be brought close to the mechanical properties of the film itself used for the substrate. In the gas barrier laminate used in the present invention, even when the total thickness of the gas barrier layers contained in the laminate is 1.0 μm or less (for example, 0.9 μm or less), oxygen permeation in an 85% RH atmosphere at 20 ° C. The degree can be set to 1.1 cm ³ / (m ² · day · atm) or less (for example, 1.0 cm ³ / (m ² · day · atm) or less). The thickness of one gas barrier layer is preferably 0.05 μm or more (for example, 0.15 μm or more) from the viewpoint of improving the gas barrier property of the gas barrier laminate. Further, the total thickness of the gas barrier layer is more preferably 0.1 μm or more (for example, 0.2 μm or more). The thickness of the gas barrier layer can be controlled by the concentration of the solution used for forming the gas barrier layer and the coating method.

  In addition, the laminate of the present invention may include a layer made of an inorganic material (hereinafter sometimes referred to as “inorganic layer”) between the base material and the gas barrier layer. The inorganic layer can be formed of an inorganic material such as an inorganic oxide. The inorganic layer can be formed by a vapor deposition method such as a vapor deposition method.

  The inorganic substance which comprises an inorganic layer should just have gas barrier property with respect to oxygen, water vapor | steam, etc., Preferably it has transparency. For example, the inorganic layer can be formed using an inorganic oxide such as aluminum oxide, silicon oxide, silicon oxynitride, magnesium oxide, tin oxide, or a mixture thereof. Among these, aluminum oxide, silicon oxide, and magnesium oxide can be preferably used from the viewpoint of excellent barrier properties against gases such as oxygen and water vapor.

  Although the preferable thickness of an inorganic layer changes with kinds of inorganic oxide which comprises an inorganic layer, it is the range of 2 nm-500 nm normally. Within this range, a thickness that provides good gas barrier properties and mechanical properties of the gas barrier laminate may be selected. When the thickness of the inorganic layer is less than 2 nm, the expression of the barrier property of the inorganic layer with respect to a gas such as oxygen or water vapor is not reproducible, and the inorganic layer may not exhibit a sufficient gas barrier property. When the thickness of the inorganic layer exceeds 500 nm, the gas barrier property tends to be lowered when the gas barrier laminate is pulled or bent. The thickness of the inorganic layer is preferably in the range of 5 to 200 nm, more preferably in the range of 10 to 100 nm.

  The inorganic layer can be formed by depositing an inorganic oxide on the substrate. Examples of the forming method include a vacuum deposition method, a sputtering method, an ion plating method, a chemical vapor deposition method (CVD), and the like. Among these, the vacuum evaporation method can be preferably used from the viewpoint of productivity. As a heating method in performing vacuum deposition, any of an electron beam heating method, a resistance heating method, and an induction heating method is preferable. Moreover, in order to improve the adhesiveness of an inorganic layer and a base material, and the denseness of an inorganic layer, you may vapor-deposit using a plasma assist method or an ion beam assist method. Moreover, in order to raise the transparency of an inorganic layer, you may employ | adopt the reactive vapor deposition method which blows in oxygen gas etc. and produces a reaction in the case of vapor deposition.

  The fine structure of the gas barrier layer is not particularly limited. However, when the gas barrier layer has the fine structure described below, it is preferable because a decrease in gas barrier properties when the gas barrier laminate is stretched can be suppressed. A preferable fine structure is a sea-island structure composed of a sea phase (α) and an island phase (β). The island phase (β) is a region where the ratio of the hydrolysis condensate of the compound (L) is higher than that of the sea phase (α).

  Each of the sea phase (α) and the island phase (β) preferably further has a fine structure. For example, the sea phase (α) is composed of a sea phase (α1) mainly composed of a neutralized product of a carboxylic acid-containing polymer and an island phase (α2) mainly composed of a hydrolysis condensate of the compound (L). The sea island structure to be formed may be further formed. The island phase (β) is composed of a sea phase (β1) mainly composed of a neutralized product of a carboxylic acid-containing polymer and an island phase (β2) mainly composed of a hydrolysis condensate of the compound (L). The sea island structure to be formed may be further formed. The ratio (volume ratio) of [island phase (β2) / sea phase (β1)] in the island phase (β) is the ratio of [island phase (α2) / sea phase (α1)] in the sea phase (α). Is preferably larger. The diameter of the island phase (β) is preferably in the range of 30 nm to 1200 nm, more preferably in the range of 50 to 500 nm, and still more preferably in the range of 50 nm to 400 nm. The diameter of the island phase (β2) and the island phase (α2) is preferably 50 nm or less, more preferably 30 nm or less, and even more preferably 20 nm or less.

  In order to obtain the structure as described above, it is necessary that the appropriate hydrolysis condensation of the compound (L) occurs in preference to the crosslinking reaction between the compound (L) and the carboxylic acid-containing polymer. For this purpose, the specific compound (L) is used in an appropriate ratio with the carboxylic acid-containing polymer, and the compound (L) is preliminarily hydrolyzed and condensed before mixing with the carboxylic acid-containing polymer. A method such as using a condensation catalyst can be employed.

  Moreover, when specific manufacturing conditions were selected, it was found that a region where the ratio of the hydrolysis condensate of compound (L) is high is formed in a layered manner on the surface of the gas barrier layer. Hereinafter, the layer of the hydrolytic condensate of compound (L) formed on the surface of the gas barrier layer may be referred to as “skin layer”. By forming the skin layer, the water resistance of the gas barrier layer surface is improved. The skin layer made of the hydrolyzed condensate of compound (L) has a characteristic that the hydrophobic property is imparted to the surface of the gas barrier layer, and the gas barrier layer does not stick even when the gas barrier layers wet with water are stacked. To grant. Surprisingly, even when a skin layer having hydrophobic characteristics is formed on the surface of the gas barrier layer, the wettability of the printing ink or the like to the surface is good. The presence or absence of the skin layer of the gas barrier layer or the state of the formed skin layer varies depending on the production conditions. As a result of intensive studies, the present inventors have found that there is a correlation between the contact angle between the gas barrier layer and water and the preferred skin layer, and the preferred skin layer is formed when the contact angle satisfies the following conditions. I found out. When the contact angle between the gas barrier layer and water is less than 20 °, the skin layer may not be sufficiently formed. In this case, the surface of the gas barrier layer easily swells with water, and if the laminates are stacked in a wet state, they may rarely stick together. Further, when the contact angle is 20 ° or more, the skin layer is sufficiently formed, and the surface of the gas barrier layer does not swell with water, so that no sticking occurs. The contact angle between the gas barrier layer and water is preferably 24 ° or more, and more preferably 26 ° or more. On the other hand, when the contact angle is larger than 65 °, the skin layer becomes too thick and the transparency of the gas barrier laminate is lowered. Therefore, the contact angle is preferably 65 ° or less, more preferably 60 ° or less, and still more preferably 58 ° or less.

  The gas barrier laminate may have various laminate structures. In the following description, a multilayer film including a base material other than the paper layer and a gas barrier layer formed on the base material may be referred to as a “gas barrier multilayer film”. The gas barrier laminate may have the following laminate structure.

(1) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer,
(2) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / hydroxyl group-containing polymer layer,
(3) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyester layer,
(4) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyamide layer,
(5) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / biaxially stretched heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer,
(6) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / biaxially stretched heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / hydroxyl group-containing polymer layer,
(7) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / biaxially stretched heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyester layer,
(8) Heat-resistant polyolefin layer / paper layer / heat-resistant polyolefin layer / biaxially stretched heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyamide layer,
(9) Paper layer / Heat resistant polyolefin layer / Gas barrier multilayer film / Heat resistant polyolefin layer,
Paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / hydroxyl group-containing polymer layer,
(10) Paper layer / heat-resistant polyolefin layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyester layer,
(11) Paper layer / heat resistant polyolefin layer / gas barrier multilayer film / heat resistant polyolefin layer / polyamide layer,
(12) Heat resistant polyolefin layer / paper layer / gas barrier multilayer film / heat resistant polyolefin layer,
(13) Heat-resistant polyolefin layer / paper layer / gas barrier multilayer film / heat-resistant polyolefin layer / hydroxyl group-containing polymer layer,
(14) Heat-resistant polyolefin layer / paper layer / gas barrier multilayer film / heat-resistant polyolefin layer / polyester layer,
(15) Paper layer / Gas barrier multilayer film / Heat resistant polyolefin layer / Polyamide layer,
(16) Gas barrier multilayer film / paper layer / heat-resistant polyolefin layer,
(17) Gas barrier multilayer film / paper layer / heat resistant polyolefin layer / hydroxyl group-containing polymer layer,
(18) Gas barrier multilayer film / paper layer / heat resistant polyolefin layer / polyester layer,
(19) Gas barrier multilayer film / paper layer / heat-resistant polyolefin layer / polyamide layer.

  An adhesive layer may be disposed between the layers. In the above example, the heat-resistant polyolefin layer is composed of either a biaxially stretched heat-resistant polyolefin film or an unstretched heat-resistant polyolefin film.

  From the viewpoint of ease of molding, the heat-resistant polyolefin layer disposed in the outermost layer of the gas barrier laminate is preferably an unstretched polypropylene film. Similarly, the heat-resistant polyolefin layer disposed inside the outermost layer of the gas barrier laminate is preferably an unstretched polypropylene film. In a preferred example, all the heat resistant polyolefin layers constituting the gas barrier laminate are unstretched polypropylene films.

  As the hydroxyl group-containing polymer layer, a film obtained by extruding an ethylene / vinyl alcohol copolymer can be used. The hydroxyl group-containing polymer layer may be a uniaxially stretched film, a biaxially stretched film, or an unstretched film, but a biaxially stretched film is preferred. The thickness of the hydroxyl group-containing polymer layer is not particularly limited, but is preferably in the range of 5 μm to 200 μm, and more preferably in the range of 5 μm to 100 μm, from the viewpoints of gas barrier properties, mechanical toughness, workability, and the like. .

  Moreover, the paper container of this invention may be provided with the window part which does not contain a paper layer. The window can be formed by cutting out a part of the paper layer of the gas barrier laminate. A window part is comprised by the laminated body containing layers other than a paper layer. The window portion includes at least a gas barrier layer, and is, for example, a gas barrier multilayer film (a multilayer film including a base material and a gas barrier layer).

  The laminated body arranged to cover the window (the cutout portion of the paper layer) is formed by cutting out some paper layers (or the paper layer and other layers) of the gas barrier laminate constituting the paper container. It may be formed. Moreover, you may affix a gas barrier multilayer film from the outer side or inner side of a container, or both sides of a container so that a window part (notch part of a paper layer) may be covered.

  A laminate including a gas barrier multilayer film attached from the outside of the container, the inside of the container, or both the outside of the container and the inside of the container so as to cover the notch portion of the paper layer will be described below. .

  Examples of the laminate structure of the laminate including the gas barrier laminate covering the notch portion of the paper layer include polyolefin layer / gas barrier multilayer film / polyolefin layer, gas barrier multilayer film / polyolefin layer. An adhesive layer can be appropriately provided between the polyolefin layer and the gas barrier laminate.

  As this polyolefin layer, the thing similar to the polyolefin layer illustrated by the laminated body which has a paper layer can be mentioned.

  The polyolefin layer is preferably linear low density polyethylene or polypropylene from the viewpoint of heat resistance. The polyolefin layer is preferably unstretched linear low-density polyethylene or unstretched polypropylene, more preferably unstretched polypropylene, from the viewpoint of ease of molding. The thickness of the polypropylene layer is preferably in the range of 10 μm to 200 μm, more preferably in the range of 20 μm to 150 μm, from the viewpoint of mechanical toughness, impact resistance, puncture resistance and the like.

  A polyolefin (PO) layer (for example, an unstretched polyolefin film or a stretched polyolefin film) may be bonded to a film constituting another layer by a known dry lamination method, wet lamination method, hot melt lamination method, or the like. . Moreover, you may form a polyolefin layer on the film which comprises another layer by the well-known T-die extrusion method etc. An adhesive layer may be disposed between the polyolefin layer and other layers. The adhesive layer can be formed using an anchor coating agent, an adhesive, an adhesive resin, or the like. What is necessary is just to select the material of an contact bonding layer according to the kind of polyolefin layer.

  The end of the paper layer appears at the notch of the paper layer. If the edge is exposed, the paper container may be damaged from the edge of the paper layer. Further, when this end comes into contact with the liquid contents in the container, moisture enters from the end of the paper layer. Therefore, it is preferable to cover the end of the paper layer with a resin or the like. As a method for covering the end of the paper layer, for example, the following method can be employed. First, paper (paper layer) provided with a notch is prepared, and a laminate having a configuration of polyethylene (PE) layer / paper layer / PE layer is produced by an extrusion lamination method. By pressing the laminate before the PE is solidified, the two PE layers existing on both sides of the paper layer are bonded to each other at the notch portion of the paper layer. Thereafter, by cutting out the PE layer / PE layer in the cutout portion of the paper layer so that the end portion of the paper layer does not appear, a window portion in which the end portion of the paper layer is not exposed can be produced.

  Similarly, by preparing paper (paper layer) provided with notches, applying hot melt adhesive on both sides of the paper layer by gravure method, and then bonding the paper layer and polyethylene (PE) film together A laminate having a configuration of polyethylene (PE) layer / paper layer / PE layer is prepared. After that, by cutting out the PE layer in the cutout portion of the paper layer so that the end portion of the paper layer does not appear, a window portion where the end portion of the paper layer is not exposed can be produced.

  The gas barrier laminate may include an unstretched heat-resistant polyolefin layer disposed inside the outermost layer. The gas barrier laminate may include a substrate on which a gas barrier layer is laminated. And the inorganic layer may be arrange | positioned between the base material and the gas barrier layer. The gas barrier laminate may include at least two heat resistant polyolefin layers, and the heat resistant polyolefin layers may be laminated on both sides of the gas barrier layer. The heat resistant polyolefin layer may be a polypropylene layer. Moreover, the container of this invention may be provided with the window part which does not contain a paper layer and contains a gas barrier layer. Since there is no paper layer in the window, the contents can be visually observed through the window.

[Method for producing gas barrier laminate]
Hereinafter, a method for producing the gas barrier laminate used in the present invention will be described. According to this method, the gas barrier laminate used in the present invention can be easily produced. Since the materials used in the manufacturing method of the present invention and the configuration of the laminate are the same as those described above, description of overlapping portions may be omitted.

  The production method of the present invention includes steps (i) and (ii).

  Step (i) is a step of forming a layer comprising a composition containing the polymer (X) and the hydrolysis condensate of the compound (L) on a substrate. The layer is formed directly on the substrate or is formed on the substrate via another layer. In the composition, at least a part of —COO— group contained in the functional group (F) of the polymer (X) is neutralized and / or reacted with the compound (P) containing two or more amino groups. ing. In the composition, the ratio of [equivalent of amino group contained in compound (P)] / [equivalent of -COO-group contained in functional group (F) of polymer (X)] was 0.2 / 100. It is in the range of ~ 20.0 / 100.

  About the compound contained in a compound (L), and the ratio of those compounds, it is the same as that of what was demonstrated about the composition which comprises a gas barrier layer.

  Step (ii) is a step of bringing the layer formed in step (i) into contact with a solution containing divalent or higher valent metal ions (hereinafter, this step may be referred to as an ionization step). For example, it can be performed by spraying a solution containing divalent or higher metal ions on the formed layer, or immersing both the base material and the layer on the base material in a solution containing divalent or higher metal ions. . By step (ii), at least a part of the —COO— group contained in the functional group (F) of the polymer (X) is neutralized.

  Hereinafter, step (i) will be described in detail. In addition, since mixing of a compound (P) and a carboxylic acid containing polymer may cause both to react and the coating of a solution (U) may become difficult, a process (i) is compound (P) and It is preferable to include the process (ia) which prepares the solution (S) containing an acid (R). The method for adjusting the solution (U) is not particularly limited as long as the solution (U) can be applied, and examples thereof include the following methods.

  As the method (1), a method of adding and mixing the compound (L), the solution (S) and, if necessary, a solvent to the solution in which the polymer (X) is dissolved can be employed. Moreover, as a method (2), an oligomer (V) (one kind of hydrolysis condensate) is prepared from the compound (L) in the presence or absence of a solvent, and the polymer (X) is dissolved in the oligomer (V). A method of mixing the prepared solution and the solution (S) can also be employed. In addition, a compound (L) and an oligomer (V) may be added to a solution independently, and may be added to a solvent with the form of the solution which dissolved them.

  As a method for preparing the solution (U), a gas barrier laminate having particularly excellent gas barrier properties can be obtained by using the method (2). Hereinafter, the method (2) will be described more specifically.

  In the method of (2) above, the step (i) includes (ia) a step of preparing a solution (S) containing the compound (P) and the acid (R), and (ib) the compound (L). A step of preparing a solution (T) containing an oligomer obtained by hydrolysis and condensation, and (ic) a solution (U) containing the solution (S), the solution (T) and the polymer (X). A step of preparing, and (id) a step of forming the layer by applying the solution (U) to a substrate and drying it. Either step (ia) or step (ib) may be performed first or at the same time.

  In step (ia), a solution (S) containing compound (P) and acid (R) is prepared. By neutralizing the amino group of the compound (P) with an acid (R), it does not gel when mixed with a carboxylic acid-containing polymer. In the drying step of step (id), the acid (R) produced by the exchange reaction between the salt of the amino group of compound (P) and acid (R) and the —COO— group of the carboxylic acid polymer is used. It is preferably removed from the gas barrier layer. As a result of the exchange reaction, a neutralization reaction occurs between the amino group of compound (P) and the —COO— group of the carboxylic acid-containing polymer, and a part of the neutralized salt subsequently becomes an amide group by the amidation reaction. By these neutralization reaction and amidation reaction, the carboxylic acid-containing polymer is cross-linked and exhibits hot water resistance.

  Although acid (R) is not particularly limited, examples of preferable acid (R) include hydrochloric acid, nitric acid, carbonic acid, and acetic acid from the viewpoint of easy removal from the gas barrier layer in the drying step of step (id). Of these, hydrochloric acid is preferred. The amount of acid (R) used in solution (S) is such that the ratio of [equivalent of acid (R)] / [equivalent of amino group of compound (P)] is 0.5 / 1 or more. Good. If the conditions of 0.5 / 1 or more are satisfied, gelation at the time of mixing with the carboxylic acid-containing polymer can be prevented. From the viewpoint of better gas barrier properties of the gas barrier laminate, the ratio of [Equivalent of acid (R)] / [Equivalent of amino group of compound (P)] is in the range of 0.5 / 1 to 10/1. Preferably, it is in the range of 0.7 / 1 to 5/1, more preferably in the range of 0.7 / 1 to 2/1.

  Step (ib) includes, for example, a solution (T) containing an oligomer (V) obtained by hydrolysis and condensation of compound (A) or compound (L) containing compound (A) and compound (B). ). It is preferable to obtain oligomer (V) by hydrolyzing and condensing compound (L) in a reaction system containing compound (L), an acid catalyst, water, and if necessary, an organic solvent. Specifically, a technique used in a known sol-gel method can be applied. As the compound (L), the compound (L) may be previously hydrolyzed and condensed. Hereinafter, compound (L), compound (L) partially hydrolyzed, compound (L) completely hydrolyzed, compound (L) partially hydrolyzed and condensed, and compound (L ) May be referred to as “compound (L) -based component”.

As the acid catalyst used in the step (ib), a known acid can be used. For example, hydrochloric acid, sulfuric acid, nitric acid, p-toluenesulfonic acid, benzoic acid, acetic acid, lactic acid, butyric acid, carbonic acid, oxalic acid, malein An acid etc. are mentioned. Among these, hydrochloric acid, sulfuric acid, nitric acid, acetic acid, lactic acid, and butyric acid are particularly preferable. Preferred amount of acid catalyst may vary depending on the type of acid used, the metal atom to 1 mol of the compound (L), is preferably in the range of 1 × 10 ^-5 to 10 mol, 1 × 10 ^- It is more preferably in the range of ^{4 to} 5 mol, and further preferably in the range of 5 × 10 ⁻⁴ to 1 mol. When the amount of the acid catalyst used is within this range, a gas barrier laminate having a high gas barrier property can be obtained.

  Moreover, although the usage-amount of the water used by process (ib) changes with kinds of compound (L), it is 0.05-10 equivalent with respect to 1 equivalent of characteristic groups which have the hydrolyzability of a compound (L). Preferably, it is in the range of 0.1 to 5 equivalents, more preferably in the range of 0.2 to 3 equivalents. When the amount of water used is in this range, a gas barrier laminate having particularly excellent gas barrier properties can be obtained. In addition, when using the component containing water like hydrochloric acid in process (ib), it is preferable to determine the usage-amount of water also considering the quantity of the water introduce | transduced by the component.

  Furthermore, in the reaction system of the step (ib), an organic solvent may be used as necessary. The organic solvent used will not be specifically limited if it is a solvent in which compound (L) dissolves. For example, alcohols such as methanol, ethanol, isopropanol, and normal propanol are preferably used as the organic solvent, and alcohols having the same molecular structure (alkoxy component) as the alkoxy group contained in the compound (L) are more preferably used. It is done. Specifically, methanol is preferred for tetramethoxysilane and ethanol is preferred for tetraethoxysilane. The amount of the organic solvent used is not particularly limited, but the concentration of the compound (L) is preferably 1 to 90% by weight, more preferably 10 to 80% by weight, and still more preferably 10 to 60% by weight. preferable.

  In the step (ib), when the hydrolysis and condensation of the compound (L) is performed in the reaction system, the temperature of the reaction system is not necessarily limited, but is usually in the range of 2 to 100 ° C., preferably 4 to It is the range of 60 degreeC, More preferably, it is the range of 6-50 degreeC. The reaction time varies depending on the reaction conditions such as the amount and type of the catalyst, but is usually in the range of 0.01 to 60 hours, preferably in the range of 0.1 to 12 hours, more preferably 0.1. It is in the range of ~ 6 hours. In addition, the reaction can be performed in an atmosphere of various gases such as air, carbon dioxide, nitrogen, and argon.

  In step (ib), the entire amount of compound (L) may be added to the reaction system at once, or may be added to the reaction system in small portions several times. In any case, it is preferable that the total amount of the compound (L) used satisfies the above preferable range.

  In the step (ic), the solution (T) containing the oligomer (V) obtained in the step (ib), the solution (S) prepared in the step (ia), and the polymer (X) And preparing a solution (U) containing The solution (U) can be prepared using the solution (T), the polymer (X) (= carboxylic acid-containing polymer), the solution (S), and, if necessary, water and / or an organic solvent. For example, it is possible to employ a method of (1) mixing the solution (S) with a solution in which the carboxylic acid-containing polymer is dissolved, and then adding and mixing the solution (T). Moreover, the method of mixing (2) the solution (S) with the solution in which the carboxylic acid-containing polymer is dissolved, and adding the solution to the solution (T) and mixing can also be employed. Furthermore, (3) a method in which a solution in which a carboxylic acid-containing polymer is dissolved is added to and mixed with the solution (T), and then the solution (S) is added and mixed.

  In the above methods (1), (2), and (3), the solution (T) to be added, the solution in which the carboxylic acid-containing polymer is dissolved, and the solution (S) may be added at once. These may be added in divided portions.

  The solution in which the carboxylic acid-containing polymer is dissolved in the step (ic) can be prepared by the following method. What is necessary is just to select the solvent to be used according to the kind of carboxylic acid containing polymer. For example, in the case of a water-soluble polymer such as polyacrylic acid or polymethacrylic acid, water is suitable. In the case of a polymer such as an isobutylene-maleic anhydride copolymer or a styrene-maleic anhydride copolymer, water containing an alkaline substance such as ammonia, sodium hydroxide, or potassium hydroxide is preferred. In addition, alcohols such as methanol and ethanol; ethers such as tetrahydrofuran, dioxane and trioxane; ketones such as acetone and methyl ethyl ketone; glycols such as ethylene glycol and propylene glycol; methyl cellosolve; Glycol derivatives such as ethyl cellosolve and n-butyl cellosolve; glycerin; acetonitrile, dimethylformamide, dimethyl sulfoxide, sulfolane, dimethoxyethane and the like can be used in combination.

  In the carboxylic acid-containing polymer contained in the solution (U), a part of the —COO— group (eg, 0.1 to 10 mol%) contained in the functional group (F) is neutralized by monovalent ions. May be. The degree of neutralization of the functional group (F) with monovalent ions is more preferably in the range of 0.5 to 5 mol% from the viewpoint of improving the transparency of the gas barrier laminate, and 0.7 to 3 More preferably, it is in the range of mol%. Examples of monovalent ions include ammonium ions, pyridinium ions, sodium ions, potassium ions, and lithium ions, with ammonium ions being preferred.

  The mixing ratio of the solution (T), the polymer (X) (= carboxylic acid-containing polymer), and the solution (S) in the solution (U) is such that the composition of the obtained gas barrier layer satisfies the above-described requirements regarding the composition. There are no particular restrictions.

  The solid content concentration of the solution (U) is preferably in the range of 3% by weight to 20% by weight from the viewpoint of the storage stability of the solution (U) and the coating property of the solution (U) on the base material. It is more preferably in the range of 4% to 15% by weight, and still more preferably in the range of 5% to 12% by weight.

  From the viewpoint of storage stability of the solution (U) and gas barrier properties of the gas barrier laminate, the pH of the solution (U) is preferably in the range of 1.0 to 7.0, and preferably 1.0 to 6. More preferably, it is in the range of 0, and more preferably in the range of 1.5 to 4.0.

  The pH of the solution (U) can be adjusted by a known method. For example, acidic compounds such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, acetic acid, butyric acid, ammonium sulfate, sodium hydroxide, potassium hydroxide, ammonia, trimethylamine, pyridine, It can adjust by adding basic compounds, such as sodium carbonate and sodium acetate. At this time, if a basic compound that provides a monovalent cation is used in the solution, a part of the carboxyl group and / or carboxylic anhydride group of the carboxylic acid-containing polymer may be neutralized with a monovalent ion. it can.

Step (id) will be described. The state of the solution (U) prepared in the step (ic) changes with time, and finally becomes a gel-like composition. The time until the solution (U) becomes gelled depends on the composition of the solution (U). In order to stably apply the solution (U) to the substrate, it is preferable that the solution (U) has a stable viscosity over a long period of time and then gradually increases in viscosity. The solution (U) was measured with a Brookfield viscometer (B-type viscometer: 60 rpm) even after standing at 25 ° C. for 2 days, based on the total amount of the compound (L) component. Is preferably adjusted to be 1 N · s / m ² or less (more preferably 0.5 N · s / m ² or less, particularly preferably 0.2 N · s / m ² or less). The solution (U) has a viscosity of 1 N · s / m ² or less (more preferably 0.1 N · s / m ² or less, particularly preferably 0. It is more preferable to adjust the composition so as to be 05 N · s / m ² or less. The solution (U) has a viscosity of 1 N · s / m ² or less (more preferably 0.1 N · s / m ² or less, particularly preferably 0. More preferably, the composition is adjusted to be 05 N · s / m ² or less. When the viscosity of the solution (U) is in the above range, the storage stability is excellent and the gas barrier property of the obtained gas barrier laminate is often improved.

  In order to adjust the viscosity of the solution (U) to be within the above range, for example, adjusting the concentration of solids, adjusting pH, carboxymethylcellulose, starch, bentonite, tragacanth gum, stearate, alginate, A method of adding a viscosity modifier such as methanol, ethanol, n-propanol, or isopropanol can be used.

  In addition, in order to facilitate the application of the solution (U) to the base material, an organic solvent that can be uniformly mixed with the solution (U) is added so long as the stability of the solution (U) is not hindered. May be. Examples of organic solvents that can be added include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ethers such as tetrahydrofuran, dioxane, and trioxane; ketones such as acetone, methyl ethyl ketone, methyl vinyl ketone, and methyl isopropyl ketone; ethylene glycol, Glycols such as propylene glycol; glycol derivatives such as methyl cellosolve, ethyl cellosolve, n-butyl cellosolve; glycerin; acetonitrile, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, sulfolane, dimethoxyethane and the like.

  In addition, the solution (U) may be carbonate, hydrochloride, nitrate, hydrogen carbonate, sulfate, hydrogen sulfate, phosphate, borate, alumina as long as it does not impair the effects of the present invention. Inorganic acid metal salts such as acid salts; organic acid metal salts such as oxalate, acetate, tartrate and stearate; acetylacetonate metal complexes such as aluminum acetylacetonate; cyclopentadiene such as titanocene Metal complexes such as enyl metal complexes and cyano metal complexes; layered clay compounds, crosslinking agents, compounds containing two or more amino groups as described above (P), compounds containing two or more hydroxyl groups as described above (Q), and other It may contain a polymer compound, a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant and the like. The solution (U) may contain fine metal oxide powder or fine silica powder.

  The solution (U) prepared in the step (ic) is applied to at least one surface of the substrate in the step (id). Before applying the solution (U), the surface of the substrate may be treated with a known anchor coating agent, or a known adhesive may be applied to the surface of the substrate. The method for applying the solution (U) to the substrate is not particularly limited, and a known method can be used. Preferred methods include, for example, a casting method, a dipping method, a roll coating method, a gravure coating method, a screen printing method, a reverse coating method, a spray coating method, a kiss coating method, a die coating method, a metering bar coating method, and a chamber doctor combined coating method. And curtain coating method.

  After applying the solution (U) on the substrate in the step (id), the solvent contained in the solution (U) is removed to obtain a laminate (laminate (I)) before the ionization step. It is done. The method for removing the solvent is not particularly limited, and a known method can be applied. Specifically, methods such as a hot air drying method, a hot roll contact method, an infrared heating method, and a microwave heating method can be applied alone or in combination. A drying temperature will not be restrict | limited especially if it is 15-20 degreeC or more lower than the flow start temperature of a base material, and 15-20 degreeC or more lower than the thermal decomposition start temperature of a carboxylic acid containing polymer. The drying temperature is preferably in the range of 70 ° C to 200 ° C, more preferably in the range of 80 to 180 ° C, and further preferably in the range of 90 to 160 ° C. The removal of the solvent may be carried out under normal pressure or reduced pressure.

  In the gas barrier laminate used in the present invention, a skin layer made of a hydrolyzable condensate of compound (L) is preferably formed on the surface of the gas barrier layer. Further, as described above, it is not preferable that the skin layer becomes too thick because the transparency of the gas barrier laminate is lowered. A method for forming a skin layer having an appropriate thickness will be described below. According to the results of intensive studies by the present inventors, the presence or absence of the skin layer and the state of the skin layer formation are determined by the reactivity of the hydrolyzable condensate of the compound (L), the composition of the compound (L), It depends on the solvent used in the solution (U), the drying speed of the solution (U) after the solution (U) is applied to the substrate, and the like. For example, when the contact angle of water with respect to the gas barrier layer surface is measured and the contact angle is smaller than the above-described predetermined range, by increasing the reaction time of the step (ib) and the step (ic), It is possible to increase the contact angle (that is, to form an appropriate skin layer). On the contrary, when the contact angle is larger than the predetermined range, it is possible to reduce the contact angle by shortening the reaction time of the step (ib) and the step (ic).

  In the step (ii), the laminate (I) obtained by the above step is brought into contact with a solution containing metal ions having a valence of 2 or more (hereinafter sometimes referred to as solution (IW)) (ionization step), A gas barrier laminate (laminate (II)) is obtained. The ionization process may be performed at any stage as long as the effects of the present invention are not impaired. For example, the ionization step may be performed before or after being processed into the form of the packaging material, or may be performed after the packaging material is filled with the contents and sealed.

  The solution (IW) can be prepared by dissolving, in a solvent, a compound that releases a divalent or higher valent metal ion (polyvalent metal compound) upon dissolution. As a solvent used in preparing the solution (IW), it is desirable to use water, but it may be a mixture of an organic solvent miscible with water and water. Examples of such organic solvents include alcohols such as methanol, ethanol, n-propanol, and isopropanol; ethers such as tetrahydrofuran, dioxane, and trioxane; ketones such as acetone, methyl ethyl ketone, methyl vinyl ketone, and methyl isopropyl ketone; ethylene glycol, propylene glycol Glycols such as methyl cellosolve, ethyl cellosolve, and n-butyl cellosolve; glycerin; organic solvents such as acetonitrile, dimethylformamide, dimethylacetamide, dimethylsulfoxide, sulfolane, and dimethoxyethane.

As the polyvalent metal compound, compounds capable of releasing the metal ions exemplified for the gas barrier laminate (that is, divalent or higher metal ions) can be used. For example, calcium acetate, calcium hydroxide, barium hydroxide, calcium chloride, calcium nitrate, calcium carbonate, magnesium acetate, magnesium hydroxide, magnesium chloride, magnesium carbonate, iron (II) acetate, iron (II) chloride, iron acetate ( III), iron chloride (III), zinc acetate, zinc chloride, copper acetate (II), copper acetate (III), lead acetate, mercury acetate (II), barium acetate, zirconium acetate, barium chloride, barium sulfate, nickel sulfate Lead sulfate, zirconium chloride, zirconium nitrate, aluminum sulfate, potassium alum (KAl (SO ₄ ) ₂ ), titanium (IV) sulfate, and the like can be used. Only one type of polyvalent metal compound may be used, or two or more types may be used in combination. Preferred polyvalent metal compounds include calcium acetate, calcium hydroxide, magnesium acetate, and zinc acetate. In addition, you may use these polyvalent metal compounds in the form of a hydrate.

The concentration of the polyvalent metal compound in the solution (IW) is not particularly limited, but is preferably in the range of 5 × 10 ⁻⁴ wt% to 50 wt%, more preferably 1 × 10 ⁻² wt% to 30 wt%. More preferably, it is in the range of 1 to 20% by weight.

  When the laminate (I) is brought into contact with the solution (IW), the temperature of the solution (IW) is not particularly limited, but the higher the temperature, the faster the ionization rate of the carboxyl group-containing polymer. The temperature is, for example, in the range of 30 to 140 ° C, preferably in the range of 40 ° C to 120 ° C, and more preferably in the range of 50 ° C to 100 ° C.

  It is desirable to remove the solvent remaining in the laminate after contacting the laminate (I) with the solution (IW). The method for removing the solvent is not particularly limited, and a known method can be applied. Specifically, drying methods such as a hot air drying method, a hot roll contact method, an infrared heating method, and a microwave heating method can be applied singly or in combination of two or more. The temperature at which the solvent is removed is not particularly limited as long as it is 15 to 20 ° C. or more lower than the flow start temperature of the substrate and 15 to 20 ° C. or lower than the thermal decomposition start temperature of the carboxylic acid-containing polymer. The drying temperature is preferably in the range of 40 to 200 ° C, more preferably in the range of 60 to 150 ° C, and still more preferably in the range of 80 to 130 ° C. The removal of the solvent may be carried out under normal pressure or reduced pressure.

  In order not to impair the appearance of the surface of the gas barrier laminate, it is preferable to remove excess polyvalent metal compound adhering to the surface of the laminate before or after removing the solvent. As a method for removing the polyvalent metal compound, washing using a solvent in which the polyvalent metal compound dissolves is preferable. As the solvent in which the polyvalent metal compound dissolves, a solvent that can be used for the solution (IW) can be used, and the same solvent as the solvent for the solution (IW) is preferably used.

  The production method of the present invention further includes a step of heat-treating the layer formed in step (i) at a temperature of 120 to 240 ° C. after step (i) and before and / or after step (ii). But you can. That is, you may heat-process with respect to laminated body (I) or laminated body (II). The heat treatment may be performed at any stage as long as the removal of the solvent of the coated solution (U) is almost completed, but the layered product (that is, the layered product (I)) before the ionization step is performed. By performing the heat treatment, a gas barrier laminate having a good surface appearance can be obtained. The temperature of the heat treatment is preferably in the range of 120 ° C to 240 ° C, more preferably in the range of 140 to 240 ° C, and still more preferably in the range of 160 ° C to 220 ° C. The heat treatment can be performed in air, under a nitrogen atmosphere, under an argon atmosphere, or the like. By performing the heat treatment, the amidation reaction of the amino group of the compound (P) and the —COO— group of the carboxylic acid-containing polymer further proceeds. As a result, the oxygen barrier properties and appearance (transparency, etc.) after boil treatment and retort treatment are superior, and the gas barrier properties exhibit good oxygen barrier properties and appearance (transparency, etc.) even after retorting under severe retort conditions. A laminate is obtained.

  In the production method of the present invention, the laminate (I) or (II) may be irradiated with ultraviolet rays. The ultraviolet irradiation may be performed any time after the removal of the solvent of the coated solution (U) is almost completed. The method is not particularly limited, and a known method can be applied. The wavelength of the ultraviolet rays to be irradiated is preferably in the range of 170 to 250 nm, more preferably in the range of 170 to 190 nm and / or in the range of 230 to 250 nm. Further, instead of ultraviolet irradiation, radiation such as an electron beam or γ-ray may be irradiated.

  Only one of heat treatment and ultraviolet irradiation may be performed, or both may be used in combination. By performing heat treatment and / or ultraviolet irradiation, the gas barrier performance of the laminate may be expressed to a higher degree.

  In order to dispose the adhesive layer (G) between the base material and the gas barrier layer, the surface of the base material is treated (treatment with an anchor coating agent or application of an adhesive) before application of the solution (U). You may give it. In that case, after the step (i) (application of the solution (U)) and before the heat treatment and the step (ii) (ionization step), the substrate coated with the solution (U) is compared. It is preferable to perform an aging treatment that is allowed to stand at a low temperature for a long time. The temperature of the aging treatment is preferably in the range of 30 to 200 ° C, more preferably in the range of 30 to 150 ° C, and further preferably in the range of 30 to 120 ° C. The aging time is preferably in the range of 0.5 to 10 days, more preferably in the range of 1 to 7 days, and still more preferably in the range of 1 to 5 days. By performing such an aging treatment, the adhesive force between the base material and the gas barrier layer becomes stronger. After the aging treatment, it is preferable to perform the above heat treatment (heat treatment at 120 ° C. to 240 ° C.).

  Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples, when describing the layer structure of the laminate, only the substance name may be described, and the “layer” may be omitted.

[Production and evaluation of laminates and laminates]
The laminates and laminates described below were prepared and evaluated. Evaluation was performed by the following methods (1) to (8).

(1) Oxygen barrier property before retort treatment Oxygen permeability was measured using an oxygen permeation measuring device ("MOCON OX-TRAN 2/20" manufactured by Modern Control). The oxygen permeability (unit: cc / m ² / day / atm) was measured under the conditions of a temperature of 20 ° C., an oxygen pressure of 1 atm, and a carrier gas pressure of 1 atm (cc = cm ³ ). Nitrogen gas containing 2% by volume of hydrogen gas was used as the carrier gas. At this time, the humidity was set to 85% RH, and the oxygen supply side and the carrier gas side were set to the same humidity. For the laminate in which the gas barrier layer was formed only on one side of the substrate, the laminate was set so that the gas barrier layer was directed to the oxygen supply side and the substrate was directed to the carrier gas side.

(2) Oxygen barrier property after 10% elongation and before retort treatment First, the laminate was cut into 30 cm × 21 cm. Next, the cut-out laminate was stretched by 10% using a manual stretching device under the conditions of 23 ° C. and 50% RH, and held for 5 minutes in the stretched state. Thereafter, the oxygen permeability was measured by the same method as described above.

(3) Contact angle The laminate was conditioned for 24 hours under conditions of a temperature of 20 ° C and a humidity of 65% RH. Thereafter, 2 μL of water was dropped onto the gas barrier layer using an automatic contact angle meter (manufactured by Kyowa Interface Science, DM500) under conditions of a temperature of 20 ° C. and a humidity of 65% RH. And the contact angle of a gas barrier layer and water was measured by the method based on Japanese Industrial Standard (JIS) -R3257.

(4) Tensile strength and elongation, Young's modulus The laminate was conditioned for 24 hours under conditions of a temperature of 23 ° C and a humidity of 50% RH. Thereafter, the laminate was cut into 15 cm × 15 mm with respect to the MD direction and the TD direction. About the cut-out laminated body, tensile strength and Young's modulus were measured by the method based on JIS-K7127 on the conditions of temperature 23 degreeC and humidity 50% RH.

(5) Dry heat shrinkage The laminate was cut into 10 cm × 10 cm, and the length in MD and TD was measured with calipers. This laminate was heated in a dryer at 80 ° C. for 5 minutes, and the length in MD and TD after heating was measured. And the dry heat shrinkage rate was measured from the following formula.
Dry heat shrinkage (%) = (l _a −l _b ) × 100 / l _b
[Wherein _lb represents a length before heating. l _a represents the length after heating. ]

(6) Degree of neutralization of carboxyl groups by metal ions (degree of ionization)
[Calculation of ionization degree by FT-IR]
Polyacrylic acid having a number average molecular weight of 150,000 was dissolved in distilled water, and the carboxyl group was neutralized with a predetermined amount of sodium hydroxide. The obtained aqueous solution of neutralized polyacrylic acid was coated on a substrate so as to have the same thickness as the gas barrier layer of the laminate to be measured for ionization degree, and dried. The substrate was coated on the surface with a two-component anchor coating agent (Mitsui Takeda Chemical Co., Ltd., Takelac 626 (trade name) and Takenate A50 (trade name), hereinafter abbreviated as “AC”). A stretched polyamide film (manufactured by Unitika Ltd., Emblem ON-BC (trade name), thickness 15 μm, hereinafter sometimes abbreviated as “OPA”) was used. In this way, a standard sample [laminated body (layer made of neutralized polyacrylic acid / AC / OPA)] having a carboxyl group neutralization degree of 0, 25, 50, 75, 80, and 90 mol% was prepared. Produced. About these samples, the infrared absorption spectrum was measured in the mode of ATR (total reflection measurement) using the Fourier-transform infrared spectrophotometer (The product made from Perkin Elmer, Spectrum One). The two peaks corresponding to the C = O stretching vibration in the layer consisting of neutralized product of polyacrylic acid, i.e., a peak observed in the range of 1600cm ^-1 ~1850cm ^-1 and 1500cm ^-1 ~1600cm ^- The ratio of the maximum absorbance was calculated for the peak observed in the range of ¹ . And the calibration curve 1 was created using the calculated ratio and the ionization degree of each standard sample.

For a laminate using a stretched polyamide film (“OPA” above) as a substrate, a gas barrier layer in a mode of ATR (total reflection measurement) using a Fourier transform infrared spectrophotometer (Perkin Elmer, Spectrum One) The peak of the C═O stretching vibration contained in was observed. Peak attributed to C = O stretching vibration of the carboxyl group of the ionization front of a carboxylic acid-containing polymer, was observed in the range of 1600cm ^-1 ~1850cm ^-1. Furthermore, C = O stretching vibration of the carboxyl group after being ionized was observed in the range of 1500cm ^-1 ~1600cm ^-1. Then, the ratio was calculated from the maximum absorbance in each range, and the degree of ionization was determined using the ratio and the calibration curve 1.

[Calculation of ionization degree by fluorescent X-ray]
About the laminated body using OPA mentioned above as a base material, the standard sample from which the degree of ionization differs was measured from the measurement of FT-IR. Specifically, eleven types of standard samples having different degrees of ionization (ions: calcium ions) of about 10 mol% between 0 to 100 mol% were prepared. For each sample, the fluorescence X-ray intensity of calcium element was measured using a wavelength dispersion type fluorescent X-ray apparatus (manufactured by Rigaku Corporation, ZSXmini II), and a calibration curve 2 was created from the degree of ionization measured in advance by FT-IR. did. Using the obtained calibration curve 2, the degree of calcium ionization of the laminate produced under various conditions was calculated.

  Also in the case of ionization with other metal ions (magnesium ion, zinc ion, etc.), the calibration curve 2 was created by the same method as described above, and the degree of ionization was calculated.

  For a laminate (such as PET) using a substrate other than OPA, the degree of ionization was calculated using the calibration curve 2 obtained by fluorescent X-ray intensity measurement.

(7) Weight of hydrolysis condensate and polymer (X) By the method described above, the weight of the inorganic component derived from compound (L) and the weight of the organic component derived from compound (L) and polymer (X ) And the total weight of the organic components derived from it were calculated.

(8) Oxygen barrier property after retorting Two laminates (size: 12 cm × 12 cm) were produced. Then, the two sheets were laminated so that the unstretched polypropylene film (Tosero Co., Ltd., RXC-18 (trade name), thickness 50 μm, hereinafter abbreviated as “CPP”) might be inside. The three sides of the laminate were heat sealed to 5 mm from the end. After injecting 80 g of distilled water between the two heat-sealed laminates, the remaining fourth side was similarly heat-sealed. In this way, a pouch containing distilled water was produced.

  Next, the pouch was put into a retort treatment device (manufactured by Nisaka Seisakusho, Flavor Ace RCS-60), and retort treatment was performed under the conditions of 120 ° C., 30 minutes, and 0.15 MPa. After the retort treatment, heating was stopped, and the pouch was taken out from the retort treatment device when the internal temperature of the retort treatment device reached 60 ° C. Then, the pouch was left for 1 hour in a room at 20 ° C. and 65% RH. Thereafter, the heat-sealed portion was cut off with scissors, and the water adhering to the surface of the laminate was wiped off by lightly pressing a paper towel. Thereafter, the pouch was left in a desiccator adjusted to 20 ° C. and 85% RH for one day or longer. The oxygen barrier property after the retort treatment was evaluated by measuring the oxygen permeability of the laminate subjected to such a retort treatment.

The oxygen transmission rate was measured using an oxygen transmission amount measuring device ("MOCON OX-TRAN 2/20" manufactured by Modern Control). Specifically, the laminate is set so that the gas barrier layer faces the oxygen supply side and the CPP faces the carrier gas side, the temperature is 20 ° C., the humidity is 85% RH on the oxygen supply side, the humidity is 85% RH on the carrier gas side, The oxygen permeability (unit: cc / m ² / day / atm) was measured under conditions of an oxygen pressure of 1 atm and a carrier gas pressure of 1 atm.

<Laminated body (1)>
Polyacrylic acid (PAA) having a number average molecular weight of 150,000 was dissolved in distilled water to obtain a PAA aqueous solution having a solid content concentration of 13% by weight in the aqueous solution. Subsequently, 13% ammonia aqueous solution was added to this PAA aqueous solution to neutralize 1 mol% of the carboxyl group of PAA, thereby obtaining a partially neutralized aqueous solution of PAA.

  Moreover, 1N-HCl was added to EDA so that the equivalent ratio of [amino group contained in ethylenediamine (EDA)] / [HCl] was 1/1, to obtain an EDA hydrochloride aqueous solution (S1).

  Subsequently, the ratio of [weight of inorganic component derived from tetramethoxysilane (TMOS)] / [weight of partially neutralized PAA] was 30.0 / 70.0, and [amino group of EDA] / [PAA The mixed solution (U1) was prepared so that the equivalent ratio of [carboxyl group] was 0.2 / 100. Specifically, first, 50 parts by weight of TMOS was dissolved in 50 parts by weight of methanol. Subsequently, 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid were added so that the ratio of water to TMOS was 1.95 molar equivalent, and hydrolysis was performed at 10 ° C. for 1 hour. Then, a condensation reaction was performed to obtain a mixed liquid (T1). Next, after diluting the mixed liquid (T1) with 567 parts by weight of distilled water and 283 parts by weight of methanol, 354 parts by weight of an aqueous solution of a partially neutralized product of PAA (concentration 13% by weight) was rapidly added while stirring. Furthermore, 1.27 parts by weight of the above-mentioned EDA hydrochloride aqueous solution (S1) was added to obtain a mixed solution (U1) having a solid content concentration of 5% by weight.

  On the other hand, a two-component anchor coating agent dissolved in 67 parts by weight of ethyl acetate (Mitsui Takeda Chemical Co., Ltd .: Takelac A-626 (trade name) 1 part by weight and Takenate A-50 (trade name) 2 parts by weight) Is coated on a stretched polyethylene terephthalate film (manufactured by Toray Industries, Inc., Lumirror P60 (trade name), thickness 12 μm, hereinafter sometimes abbreviated as “PET”), and dried to form a base material having an anchor coat layer (AC / PET) was prepared. The mixed solution (U1) was coated on the anchor coat layer of the base material with a bar coater so that the thickness after drying was 0.4 μm, and dried at 120 ° C. for 5 minutes. Subsequently, coating was also performed on the opposite surface of the substrate in the same procedure. The obtained laminate was aged at 40 ° C. for 3 days. Next, the laminate was heat-treated at 180 ° C. for 5 minutes using a dryer. Next, the laminate was immersed in a 2 wt% aqueous calcium acetate solution (85 ° C.) for 12 seconds, and then dried at 110 ° C. for 1 minute. In this way, a laminate (1) having a structure of gas barrier layer (0.4 μm) / AC (0.1 μm) / PET (12 μm) / AC (0.1 μm) / gas barrier layer (0.4 μm) is obtained. It was.

<Laminated body (2)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). A mixed liquid (U2) was prepared at the same charging ratio as that of the laminate (1) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 1.0 / 100. did. Specifically, first, the mixture (T2) prepared by the same composition and method as the mixture (T1) of the laminate (1) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then stirred. 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was quickly added, and 6.3 parts by weight of an aqueous EDA hydrochloride solution (S2) was further added. U2) was obtained.

  Using the mixed solution (U2), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (2).

<Laminated body (3)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). And the liquid mixture (U3) was prepared by changing only reaction time by the preparation ratio similar to a laminated body (1).

  Specifically, first, 50 parts by weight of TMOS was dissolved in 50 parts by weight of methanol. Thereto was added 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid so that the ratio of water to TMOS was 1.95 molar equivalents, and hydrolysis and condensation reaction at 10 ° C. for 5 hours. And a liquid mixture (T3) was obtained. Next, after the mixed liquid (T3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 1.27 parts by weight of an EDA hydrochloride aqueous solution (S3) was added to obtain a mixed liquid (U3) having a solid content concentration of 5% by weight.

  Using the mixed solution (U3), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a gas barrier laminate (3).

<Laminated body (4)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). A mixed liquid (U4) was prepared at the same charging ratio as that of the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 19.4 / 100. did. Specifically, first, the mixture (T4) prepared by the same composition and method as the mixture (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then stirred. While adding 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight), 127 parts by weight of an aqueous EDA hydrochloride solution (S4) was further added, and a mixed liquid (U4) having a solid content concentration of 5% by weight. Got.

  Using the mixed solution (U4), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (4).

<Laminated body (5)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). A mixed liquid (U5) was prepared at the same charging ratio as that of the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 4.9 / 100. did. Specifically, first, the mixture (T5) prepared by the same composition and method as the mixture (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then stirred. While quickly adding 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight), 32 parts by weight of an EDA hydrochloride aqueous solution (S5) was added, and a mixed liquid (U5) having a solid content concentration of 5% by weight was added. Obtained.

  Using the mixed solution (U5), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a gas barrier laminate (5).

<Laminated body (6)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). Then, a mixed liquid (U6) was prepared with the same charging ratio as that of the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 1.0 / 100. did. Specifically, first, the mixture (T6) prepared by the same composition and method as the mixture (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then stirred. While adding 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight), 6.3 parts by weight of an aqueous EDA hydrochloride solution (S6) was further added, and a mixed liquid (U6 )

  Using the mixed solution (U6), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (6).

<Laminated body (7)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). Subsequently, the molar ratio of [TMOS] / [γ-glycidoxydoxypropyltrimethoxysilane (GPTMOS)] is 99.5 / 0.5, [inorganic component derived from TMOS and GPTMOS] / [organic component of GPTMOS) And a partially neutralized product of PAA] in a mixed solution (so that the molar ratio of 30.0 / 70.0 and [amino group of EDA] / [carboxyl group of PAA] is 1.0 / 100) U7) was prepared. Specifically, first, 49.6 parts by weight of TMOS and 0.4 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalents, and 5 hours at 10 ° C. Hydrolysis and condensation reaction were performed to obtain a mixed solution (T7). Subsequently, after the mixed solution (T7) was diluted with 566 parts by weight of distilled water and 284 parts by weight of methanol, 352 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 6.3 parts by weight of an EDA hydrochloride aqueous solution (S7) was added to obtain a mixed solution (U7) having a solid content concentration of 5% by weight.

  Using the mixed solution (U7), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (7).

<Laminated body (8)>
A mixed solution (U8) was prepared with the same charging ratio as that of the laminate (7) except that the molar ratio of TMOS / GPTMOS was 80.0 / 20.0. Specifically, first, 36 parts by weight of TMOS and 14 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 3.0 parts by weight of distilled water and 7.4 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalents. Decomposition | disassembly and condensation reaction were performed and the liquid mixture (T8) was obtained. Subsequently, after the mixed liquid (T8) was diluted with 520 parts by weight of distilled water and 301 parts by weight of methanol, 267 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 4.8 parts by weight of an EDA hydrochloride aqueous solution (S8) was added to obtain a mixed solution (U8) having a solid content concentration of 5% by weight.

  Using the mixed solution (U8), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (8).

<Laminated body (9)>
A mixed solution (U9) was prepared with the same charging ratio as that of the laminate (7) except that the molar ratio of TMOS / GPTMOS was 89.9 / 10.1. Specifically, first, 42.6 parts by weight of TMOS and 7.4 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 3.2 parts by weight of distilled water and 7.8 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalent, and the mixture was hydrolyzed at 10 ° C for 5 hours. Decomposition | disassembly and condensation reaction were performed and the liquid mixture (T9) was obtained. Subsequently, after the mixture (T9) was diluted with 542 parts by weight of distilled water and 293 parts by weight of methanol, 308 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Furthermore, 5.5 parts by weight of an EDA hydrochloride aqueous solution (S9) was added to obtain a mixed solution (U9) having a solid content concentration of 5% by weight.

  Using the mixed solution (U9), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (9).

<Laminated body (10)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). Subsequently, the molar ratio of [TMOS] / [GPTMOS] was 98.0 / 2.0, and the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA]. Was 32.4 / 67.6, and a mixed solution (U10) was prepared so that the molar ratio of [amino group of EDA] / [carboxyl group of PAA] was 1.1 / 100. Specifically, first, 48.5 parts by weight of TMOS and 1.5 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalents, and the mixture was hydrolyzed at 10 ° C. for 5 hours. Decomposition and condensation reactions were performed to obtain a mixed solution (T10). Subsequently, after the mixed liquid (T10) was diluted with 562 parts by weight of distilled water and 293 parts by weight of methanol, 308 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 6.2 parts by weight of an EDA hydrochloride aqueous solution (S10) was added to obtain a mixed solution (U10) having a solid content concentration of 5% by weight.

  Using the mixed solution (U10), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (10).

<Laminated body (11)>
A mixed solution (U11) was obtained with the same charging ratio as that of the laminate (7) except that the molar ratio of TMOS to GPTMOS was 99.9 / 0.1. Specifically, first, 49.9 parts by weight of TMOS and 0.1 part by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalents, and the mixture was hydrolyzed at 10 ° C. for 5 hours. Decomposition | disassembly and condensation reaction were performed and the liquid mixture (T11) was obtained. Subsequently, after the mixture (T11) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 6.3 parts by weight of an EDA hydrochloride aqueous solution (S11) was added to obtain a mixed solution (U11) having a solid content concentration of 5% by weight.

  Using the mixed solution (U11), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (11).

<Laminated body (12)>
A mixed solution (U12) was prepared with the same charging ratio as that of the laminate (7) except that the molar ratio of TMOS / GPTMOS was 70.0 / 30.0. Specifically, first, 30 parts by weight of TMOS and 20 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Thereto was added 2.9 parts by weight of distilled water and 7.0 parts by weight of 0.1N hydrochloric acid so that the ratio of water to the total of TMOS and GPTMOS was 1.95 molar equivalents, Decomposition and condensation reactions were performed to obtain a mixed solution (T12). Subsequently, after the mixed solution (T12) was diluted with 500 parts by weight of distilled water and 310 parts by weight of methanol, 229 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Furthermore, 4.1 parts by weight of an EDA hydrochloride aqueous solution (S12) was added to obtain a mixed solution (U12) having a solid content concentration of 5% by weight.

  Using the mixed solution (U12), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (12).

<Laminated body (13)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). The laminate (10) except that the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 20.0 / 80.0. A mixed solution (U13) was prepared at the same charging ratio. Specifically, first, a mixed solution (T13) was obtained by the same composition and method as the mixed solution (T10) of the laminate (10). Subsequently, after the mixture (T13) was diluted with 842 parts by weight of distilled water and 405 parts by weight of methanol, 595 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Furthermore, 10.6 parts by weight of an EDA hydrochloride aqueous solution (S13) was added to obtain a mixed solution (U13) having a solid content concentration of 5% by weight.

  Using the mixed solution (U13), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (13).

<Laminated body (14)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). The laminated body (10) except that the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 80.0 / 20.0. A mixed solution (U14) was prepared at the same charging ratio. Specifically, first, a mixed solution (T14) was obtained by the same composition and method as the mixed solution (T10) of the laminate (10). Subsequently, after the mixture (T14) was diluted with 211 parts by weight of distilled water and 135 parts by weight of methanol, 32 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 0.6 part by weight of an EDA hydrochloride aqueous solution (S14) was added to obtain a mixed solution (U14) having a solid content concentration of 5% by weight.

  Using the mixed solution (U14), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (14).

<Laminated body (15)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). The laminate (10) except that the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 69.9 / 30.1 A mixed liquid (U15) was obtained with the same charging ratio. Specifically, first, a mixed solution (T15) was obtained by the same composition and method as the mixed solution (T10) of the laminate (10). Subsequently, after the mixture (T15) was diluted with 241 parts by weight of distilled water and 148 parts by weight of methanol, 59 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Furthermore, 1.0 part by weight of an EDA hydrochloride aqueous solution (S15) was added to obtain a mixed liquid (U15) having a solid content concentration of 5% by weight.

  Using the mixed solution (U15), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (15).

<Laminated body (16)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). The laminate (10) except that the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 10.0 / 90.0. A mixed solution (U16) was obtained with the same charging ratio. Specifically, first, a mixed solution (T16) was obtained by the same composition and method as the mixed solution (T10) of the laminate (10). Subsequently, after the mixture (T16) was diluted with 1683 parts by weight of distilled water and 766 parts by weight of methanol, 1346 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 24 parts by weight of an EDA hydrochloride aqueous solution (S16) was added to obtain a mixed solution (U16) having a solid content concentration of 5% by weight.

  Using the mixed solution (U16), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (16).

<Laminated body (17)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). The laminate (10) except that the weight ratio of [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 90.0 / 10.0. A mixed liquid (U17) was obtained with the same charging ratio. Specifically, first, a mixed solution (T17) was obtained by the same composition and method as the mixed solution (T10) of the laminate (10). Subsequently, after the mixture (T17) was diluted with 188 parts by weight of distilled water and 125 parts by weight of methanol, 11 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring. Further, 0.2 part by weight of an EDA hydrochloride aqueous solution (S17) was added to obtain a mixed solution (U17) having a solid content concentration of 5% by weight.

  Using the mixed solution (U17), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (17).

<Laminated body (18)>
1N-HCl was added to PDA so that the equivalent ratio of [amino group contained in propylenediamine (PDA)] / [HCl] was 1/1 to obtain PDA hydrochloride aqueous solution (S18). A mixed solution (U18) was obtained by the same composition and method as the mixed solution (U10) of the laminate (10) except that the EDA hydrochloride aqueous solution was changed to the PDA hydrochloride aqueous solution (S18).

  Using the mixed solution (U18), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (18).

<Laminated body (19)>
1N-HCl was added to chitosan so that the equivalent ratio of [amino group contained in chitosan] / [HCl] was 1/1 to obtain an aqueous chitosan hydrochloride solution (S19). A mixed solution (U19) was obtained by the same composition and method as the mixed solution (U10) of the laminate (10) except that the EDA hydrochloride aqueous solution was changed to a chitosan hydrochloride aqueous solution (S19).

  Using the mixed solution (U19), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (19).

<Laminated body (20)>
1N-HCl was added to HMDA so that the equivalent ratio of [amino group contained in hexamethylenediamine (HMDA)] / [HCl] was 1/1 to obtain an aqueous HMDA hydrochloride (S20). A mixed solution (U20) was obtained by the same composition and method as the mixed solution (U10) of the laminate (10) except that the EDA hydrochloride aqueous solution was changed to the HMDA hydrochloride aqueous solution (S20).

  Using the mixed solution (U20), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (20).

<Laminated body (21)>
For the production of the laminate (21), a mixture (U21) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used.

  Using the mixed solution (U21), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate. Ionization was performed by immersing this laminate in a 0.1 wt% aqueous calcium acetate solution (85 ° C.) for 12 seconds. Next, the laminate (21) was obtained by drying the laminate in the same manner as the laminate (1).

<Laminated body (22)>
For the production of the laminate (22), a mixture (U22) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used.

  Using the mixed solution (U22), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate. Ionization was performed by immersing this laminate in a 0.2 wt% calcium acetate aqueous solution (85 ° C.) for 6 seconds. Next, this laminate was dried in the same manner as the laminate (1) to obtain a laminate (22).

<Laminated body (23)>
For the production of the laminate (23), a mixture (U23) obtained by the same composition and method as the mixture (U10) obtained from the laminate (10) was used.

  Using the mixed solution (U23), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate. Ionization was performed by immersing this laminate in a 0.2 wt% aqueous calcium acetate solution (85 ° C.) for 12 seconds. Next, the laminate (23) was obtained by drying the laminate in the same manner as the laminate (1).

<Laminated body (24)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). On the other hand, polyvinyl alcohol (manufactured by Kuraray Co., Ltd., PVA117 (trade name), hereinafter sometimes abbreviated as “PVA”) is added to distilled water so as to be 10% by weight, and heated at 85 ° C. for 3 hours. An aqueous solution was obtained.

  The mixed solution (U24) was prepared at the same charging ratio as the laminate (6) except that the PVA aqueous solution was added so that the equivalent ratio of [hydroxyl group of PVA] / [carboxyl group of PAA] was 18.2 / 100. Obtained.

  Specifically, first, after the liquid mixture (T24) obtained by the same composition and method as the liquid mixture (T6) of the laminate (6) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, While stirring, 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added, and further 6.3 parts by weight of an aqueous EDA hydrochloride solution (S24) was added, followed by the above-mentioned 10% by weight PVA aqueous solution 51 Part by weight was added. In this way, a liquid mixture (U24) having a solid content concentration of 5% by weight was obtained.

  Using the mixed solution (U24), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (24).

<Laminated body (25)>
For the production of the laminate (25), a mixture (U25) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used. Using the mixed solution (U25), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate. Ionization was performed by immersing this laminate in a 2 wt% magnesium acetate aqueous solution (85 ° C.) for 12 seconds. Next, the laminate (25) was obtained by drying the laminate in the same manner as the laminate (1).

<Laminated body (26)>
For the production of the laminate (26), a mixture (U26) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used. Using the mixed solution (U26), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate. Ionization was performed by immersing this laminate in a 2 wt% zinc acetate aqueous solution (85 ° C.) for 12 seconds. Next, the laminate (26) was obtained by drying the laminate in the same manner as the laminate (1).

<Laminated body (27)>
For the production of the laminate (27), a mixed solution (U27) obtained by the same composition and method as the mixed solution (U10) of the laminate (10) was used. Coating, heat treatment, ionization and drying were carried out in the same manner as in the laminate (1) except that the mixed liquid (U27) was used and the coating was made only on one side to obtain a laminate (27).

<Laminated body (28)>
For the production of the laminate (28), a mixture (U28) obtained by the same composition and method as the mixture (U6) of the laminate (6) was used. Coating, heat treatment, ionization, and drying are performed in the same manner as in the laminate (1) except that the mixed liquid (U28) is used and the base material is a stretched polyamide film (“OPA” above) to obtain a laminate (28). It was.

<Laminated body (29)>
For the production of the laminate (29), a mixture (U29) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used.

  Except for using the mixed solution (U29), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (28) to obtain a laminate (29).

<Laminated body (30)>
For the production of the laminate (30), a mixture (U30) obtained by the same composition and method as the mixture (U6) of the laminate (6) was used. Using the mixed solution (U30), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (28) to obtain a laminate (30).

<Laminated body (31)>
For the production of the laminate (31), a mixture (U31) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used.

  Except for using the mixed solution (U31), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (28) to obtain a laminate (31).

<Laminated body (32)>
For the production of the laminate (32), a mixture (U32) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used. Coating, heat treatment, ionization, and drying were carried out in the same manner as in the laminate (28) except that the mixed liquid (U32) was used and the coating was made only on one side to obtain a laminate (32).

<Laminated body (33)>
An aqueous solution of a partially neutralized product of PAA was prepared in the same manner as in the laminate (1). Subsequently, the molar ratio of TMOS / GPTMOS was 89.9 / 10.1, the [inorganic component derived from TMOS and GPTMOS] / [partial neutralized product of organic component of GPTMOS and PAA] was 31.5 / A mixed solution (U33) was prepared so as to be 68.5. Specifically, first, 46 parts by weight of TMOS and 8 parts by weight of GPTMOS were dissolved in 50 parts by weight of methanol. Subsequently, 3.2 parts by weight of distilled water and 7.8 parts by weight of 0.1N hydrochloric acid were added so that the ratio of water to TMOS was 1.95 molar equivalent and the pH was 2 or less. Then, hydrolysis and condensation reaction were performed to obtain a mixed solution (T33). Subsequently, after the mixed solution (T33) was diluted with 61 parts by weight of distilled water, 308 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added while stirring to obtain a solid concentration of 13% by weight. % Mixed liquid (U33) was obtained.

  On the other hand, a two-component anchor coating agent dissolved in 67 parts by weight of ethyl acetate (Mitsui Takeda Chemical Co., Ltd .: Takelac A-626 (trade name) 1 part by weight and Takenate A-50 (trade name) 2 parts by weight) Was coated on a stretched polyethylene terephthalate film (the above “PET”) and dried to prepare a base material (AC (0.1 μm) / PET (12 μm)) having an anchor coat layer. The mixed solution (U33) was coated on the anchor coat layer of the base material with a bar coater so that the thickness after drying was 1.0 μm, and dried at 120 ° C. for 5 minutes. In the same procedure, the other side of the substrate was also coated. The obtained laminate was aged at 40 ° C. for 3 days. Next, the laminate was heat-treated at 180 ° C. for 5 minutes using a dryer. Next, the laminate was ionized by immersing it in a 2% by weight calcium acetate aqueous solution (85 ° C.) for 12 seconds, and then dried at 50 ° C. for 5 minutes. In this way, a laminate (33) having a structure of gas barrier layer (1.0 μm) / AC (0.1 μm) / PET (12 μm) / AC (0.1 μm) / gas barrier layer (1.0 μm) is obtained. It was.

<Laminated body (34)>
For the production of the laminate (34), a mixture (U34) obtained by the same composition and method as the mixture (U33) of the laminate (33) was used. Also, except that the base material was OPA, coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (34).

<Laminated body (35)>
A mixed liquid (U35) was obtained by the same composition and method as the mixed liquid (U33) of the laminate (33) except that the solid content concentration was 5% by weight. Specifically, first, a mixed solution (T35) prepared by the same composition and method as the mixed solution (T33) of the laminate (33) was diluted with 542 parts by weight of distilled water and 293 parts by weight of methanol. While stirring the obtained mixed solution, 308 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was quickly added thereto to obtain a mixed solution (U35) having a solid content concentration of 5% by weight.

  Using the mixed solution (U35), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (35).

<Laminated body (36)>
A mixed solution (U36) was obtained by the same composition and method as the mixed solution (U35) of the laminate (35). Except for using the mixed solution (U36), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (28) to obtain a laminate (36).

<Laminated body (37)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). On the other hand, a mixed solution (U37) was prepared with the same charging ratio as the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 0.1 / 100. did. Specifically, first, a mixed solution (T37) prepared by the same composition and method as the mixed solution (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol. While stirring the resulting mixture, 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was quickly added thereto, and 0.6 part by weight of an EDA hydrochloride aqueous solution (S37) was further added. A liquid mixture (U37) having a solid content concentration of 5% by weight was obtained.

  Using the mixed solution (U37), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (37).

<Laminated body (38)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). On the other hand, a mixed liquid (U38) was prepared with the same charging ratio as that of the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 29.0 / 100. did. Specifically, first, a mixed solution (T38) prepared by the same composition and method as the mixed solution (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol. While stirring the resulting mixture, 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was quickly added thereto, and 190 parts by weight of an aqueous EDA hydrochloride solution (S38) was further added. A mixed solution (U38) having a concentration of 5% by weight was obtained.

  Using the mixed solution (U38), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (38).

<Laminated body (39)>
A mixed solution (U39) was prepared by changing the reaction time only in the same manner as in the laminate (38). Specifically, first, 50 parts by weight of TMOS was dissolved in 50 parts by weight of methanol. Subsequently, 3.3 parts by weight of distilled water and 8.2 parts by weight of 0.1N hydrochloric acid were added so that the ratio of water to TMOS was 1.95 molar equivalent, and hydrolysis and condensation were carried out at 10 ° C. for 1 hour. Reaction was performed and the liquid mixture (T39) was obtained. The obtained mixed liquid (T39) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was rapidly added thereto while stirring. Further, 190 parts by weight of an EDA hydrochloride aqueous solution (S38) was added to obtain a mixed solution (U39) having a solid content concentration of 5% by weight.

  Using the mixed solution (U39), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (39).

<Laminated body (40)>
For the production of the laminate (40), a mixture (U40) obtained by the same composition and method as the mixture (U10) of the laminate (10) was used.

  Using the mixed solution (U40), coating and heat treatment were performed in the same manner as in the laminate (1) to obtain a laminate (40). This laminate (40) was not ionized and dried.

<Laminated body (41)>
A partially neutralized aqueous solution of PAA and an EDA hydrochloride aqueous solution were prepared in the same manner as in the laminate (1). Then, a mixed liquid (U41) was prepared with the same charging ratio as that of the laminate (3) except that the equivalent ratio of [amino group of EDA] / [carboxyl group of PAA] was 20.0 / 100. did. Specifically, first, a mixed solution (T41) prepared by the same composition and method as the mixed solution (T3) of the laminate (3) was diluted with 567 parts by weight of distilled water and 283 parts by weight of methanol, and then stirred. 354 parts by weight of a partially neutralized aqueous solution of PAA (concentration 13% by weight) was quickly added, and 131 parts by weight of an aqueous EDA hydrochloride solution (S41) was further added, and a mixed liquid (U41) having a solid content concentration of 5% by weight. Got.

  Using the mixed solution (U41), coating, heat treatment, ionization and drying were performed in the same manner as in the laminate (1) to obtain a laminate (41).

[Evaluation results of laminate]
The produced laminate was evaluated by the method described above. The stretched polyethylene terephthalate film (PET) and stretched polyamide film (OPA) used as the substrate of the laminate were evaluated in the same manner as the laminate. The production conditions for the laminate are shown in Table 1.

  Table 2 shows the evaluation results of the laminate and the substrate.

  The total thickness of the gas barrier layers of the laminate (34) is 2.0 μm. Thus, when the total thickness of the gas barrier layer is large (for example, larger than 1.0 μm), the physical properties of the laminate are greatly different from the physical properties of the base material (PET), and the workability is reduced. End up. Therefore, when the gas barrier layer is made thick, there arises a problem that productivity is lowered. On the other hand, a laminate having a thin total gas barrier layer, such as laminates (1) to (27) and (41), exhibits physical properties close to that of the base material (PET) and has good workability. is there. Further, as will be described later, in order to increase the durability of the gas barrier layer against bending, it is necessary to make the gas barrier layer thin.

[Production of laminate]
A laminate was produced using the laminate (1). First, on each of the stretched polyamide film (OPA) and the unstretched polypropylene film (CPP), a two-pack type adhesive (Mitsui Takeda Chemical Co., Ltd., A-385 (trade name) and A-50 (product) Name)) was coated and dried. And these and a laminated body (1) were laminated. Thus, a laminate (1) having a structure of laminate (1) / adhesive / OPA / adhesive / CPP was obtained. In addition, other laminates were produced and evaluated in the same manner as the laminate (1). Table 3 shows the laminate used for the production of the laminate and the evaluation results of the laminate.

[Production and evaluation of paper containers]
Brick type and gable top type paper containers (with an internal volume of 500 ml) were prepared using the laminates described above and evaluated. The appearance of the manufactured gable top type paper container is shown in FIG. The paper container 10 of FIG. 1 has a window portion 11 on the side surface. The paper container was evaluated by the following methods (1) to (3).

(1) Oxygen permeability after retorting of flat portion After injecting 500 g of distilled water into a brick type paper container (internal volume 500 ml), retorting was performed under the conditions of 120 ° C., 30 minutes, 0.15 MPa. After the retort treatment, the paper container was taken out and left for 1 week in a room maintained at 20 ° C. and 85% RH. Thereafter, the water in the paper container was drained, the sample was cut out, and the oxygen barrier property after the retort treatment was evaluated. For the measurement, an oxygen permeation measuring device (“MOCON OX-TRAN10 / 50” manufactured by Modern Control) was used. Specifically, first, a circular sample (diameter: 6.5 cm) not including a bent portion was cut out from the side surface of the brick-type paper container. Next, the circular sample is placed on a circle having a diameter of 4.5 cm opened in a 10 cm square aluminum foil (thickness 30 μm), and a two-component curing type epoxy adhesive is used between the sample and the aluminum foil. Sealed. The measurement sample thus obtained was set in a measuring apparatus, and the oxygen permeability (unit: cm ³ / (m ² · day · atm)). At this time, the humidity on the oxygen supply side and the humidity on the carrier gas side were both set to 85% RH.

(2) Oxygen permeability after retorting of bent portion When cutting out a circular sample (diameter: 6.5 cm) from a paper container after retorting, the above-mentioned "(" 1) Oxygen permeability after retorting of the bent portion was measured by the same method and conditions as in “1) Oxygen permeability after retorting”.

(3) Appearance observation after retort treatment 500 g of distilled water was poured into a gable-top paper container and sealed, and then retort treatment was performed at 135 ° C. for 60 minutes. After the retort treatment, the paper container was taken out and left at 20 ° C. in a 65% RH room for 1 hour.

  Then, the external appearance of the window part was observed. As in the case before retort processing, when the window is not cloudy, it is “very good (◎)”, and when it is slightly cloudy but there is no practical problem, it is “good (○)”. When it was cloudy, it was determined as “bad (×)”.

<Example 1>
An adhesive was applied to both sides of a 400 g / m ² board, and a polypropylene resin (PP) was extrusion laminated on both sides to form PP layers (20 μm in thickness each) on both sides of the board. Thereafter, an adhesive was applied to the surface of one PP layer, and the laminate (3) was laminated thereon. Next, an adhesive was applied to the surface of the laminate (3), and the laminate (3) and an unstretched polypropylene film (manufactured by Tosero Co., Ltd., Tosero CP RXC-18, thickness 50 μm, CPP) were bonded together. . In this way, a laminate (1A) having a configuration of PP / paperboard / PP / laminate (3) / CPP was produced. In the production of the laminate (1A), an anchor coating agent was used as necessary. A brick-type paper container was produced using the laminate (1A).

PP layers (thickness 25 μm each) were formed on both sides of the paperboard by extrusion coating polypropylene resin (PP) on both sides of the 400 g / m ² paperboard. Next, the paperboard of the part used as a window part was cut off. Next, an adhesive was applied to the surface of one PP layer, and the laminate (3) was laminated thereon. Next, a PP layer (thickness 40 μm) was formed by extrusion coating a polypropylene resin (PP) on the surface of the laminate (3). In this way, a laminate (1B) having a configuration of PP / paperboard / PP / laminate (3) / PP was produced. In the production of the laminate (1B), an anchor coating agent was used as necessary. Using the laminate (1B), a gable-top windowed paper container was prepared. The appearance of the manufactured gable top type paper container is shown in FIG. The paper container 10 of FIG. 1 has a window portion 11 on the side surface.

<Examples 2 to 17 and Comparative Examples 1 to 7>
A laminate having a laminated structure of PP / paperboard / PP / laminate / CPP was produced in the same manner as in Example 1 except that another laminate was used instead of the laminate (3). A brick-type paper container was produced in the same manner as in Example 1 except that the produced laminate was used instead of the laminate (1A).

  A laminate having a laminated structure of PP / paperboard / PP / laminate / PP was produced in the same manner as in Example 1 except that another laminate was used instead of the laminate (3). A gable top-type paper container with a window was produced in the same manner as in Example 1 except that the produced laminate was used instead of the laminate (1B).

  Table 4 shows the numbers of the laminates used in the paper containers of Examples and Comparative Examples, and the conditions for producing the laminates.

  Table 5 shows the evaluation results of the paper containers of Examples and Comparative Examples.

  The paper container of the example showed a good oxygen barrier property even after the retort treatment regardless of whether it was a bent portion or not. In addition, the window portion of the paper container of the example had a good appearance even when retorting was performed under severe conditions of 135 minutes at 135 ° C.

  In the examples, the ratio of [equivalent of amino group contained in compound (P)] / [equivalent of -COO-group contained in functional group of polymer (X)] was 0.2 / 100 to 20.0 /. It was shown that it was preferably in the range of 100 and more preferably in the range of 1.0 / 100 to 4.9 / 100.

In the examples, the ratio of [number of moles of M ¹ atom derived from the compound represented by formula (I)] / [number of moles of M ² atom derived from the compound represented by formula (II)] was 99. It was shown that it was preferably in the range of 0.5 / 0.5 to 80.0 / 20.0, and more preferably in the range of 98.0 / 2.0 to 89.9 / 10.1.

  In the examples, the ratio of [weight of inorganic component derived from compound (L)] / [total weight of organic component derived from compound (L) and weight of organic component derived from polymer (X)] is It was shown that it is preferably in the range of 20.0 / 80.0 to 80.0 / 20.0, and more preferably in the range of 30.0 / 70.0 to 69.9 / 30.1. .

  The paper containers of Comparative Examples 1 and 2 had relatively good oxygen barrier properties before and after the retort treatment. However, this is because the sum of the gas barrier layers of Comparative Examples 1 and 2 is as thick as 2 μm. In Comparative Examples 1 and 2 where the gas barrier layer is thick, the durability of the gas barrier layer against bending is low, and the oxygen barrier property is greatly reduced by the bending test.

  In Comparative Examples 3 to 7, in which the thickness of the gas barrier layer was the same as that of the example, the oxygen barrier property was low at any stage before the retort treatment, after the retort treatment, and after the bending test. In addition, the appearance of the window portion of the paper container of the comparative example was deteriorated by retorting at 135 ° C. for 60 minutes.

  As described above, similarly to the evaluation of the gas barrier laminate alone, the paper container of the present invention using a predetermined gas barrier layer exhibited excellent characteristics.

  The present invention can be used for paper containers. The paper container of the present invention has heat resistance that can withstand retort treatment, has a good appearance after retort treatment, and is excellent in gas barrier properties. The paper container of the present invention is also suitable for heating by a microwave oven.

It is a perspective view which shows the external appearance of the gable top type paper container produced in the Example.

Explanation of symbols

10 Paper container 11 Window

Claims (13)

A paper container formed using a gas barrier laminate,
The gas barrier laminate includes a paper layer and at least one gas barrier layer laminated on the paper layer,
The layer comprises a hydrolysis condensate of at least one compound (L) containing a hydrolyzable characteristic group, and a polymer containing at least one functional group selected from a carboxyl group and a carboxylic anhydride group. A composition comprising (X),
The compound (L) includes at least one compound (A) containing a metal atom to which a hydrolyzable characteristic group is bonded,
At least a part of —COO— group contained in the functional group of the polymer (X) is neutralized and / or reacted with a compound (P) containing two or more amino groups,
At least a part of —COO— group contained in the functional group of the polymer (X) is neutralized with a divalent or higher metal ion,
In the composition, a ratio of [equivalent of amino group contained in the compound (P)] / [equivalent of -COO-group contained in the functional group of the polymer (X)] is 0.2 / 100 to Paper container in the range of 20.0 / 100. The paper container according to claim 1, wherein the compound (A) is at least one compound represented by the following formula (I).
M ¹ (OR ¹ ) _q R ² _pqr X ¹ _r (I)
[In Formula (I), M ¹ represents Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La, or Nd. R ¹ represents an alkyl group. R ² represents an alkyl group, an aralkyl group, an aryl group or an alkenyl group. X ¹ represents a halogen atom. p is equal to the valence of M ¹ . q represents an integer of 0 to p. r represents an integer of 0 to p. 1 ≦ q + r ≦ p. ]   The compound (L) is at least one compound (B) containing a metal atom in which a hydrolyzable characteristic group and an alkyl group substituted with a functional group having reactivity with a carboxyl group are bonded. The paper container of Claim 1 or 2 containing this. The compound (B) is at least one compound represented by the following formula (II):
The ratio of [number of moles of M ¹ atom derived from the compound represented by the formula (I)] / [number of moles of M ² atom derived from the compound represented by the formula (II)] was 99.5. The paper container of Claim 3 which exists in the range of /0.5-80.0 / 20.0.
M ² (OR ³ ) _n X ² _k Z ² _mnk (II)
[In Formula (II), M ² represents Si, Al, Ti, Zr, Cu, Ca, Sr, Ba, Zn, Ga, Y, Ge, Pb, Sb, V, Ta, W, La, or Nd. R ³ represents an alkyl group. X ² represents a halogen atom. Z ² represents an alkyl group substituted with a functional group having reactivity with a carboxyl group. m is equal to the valence of M ² . n represents an integer of 0 to (m-1). k represents an integer of 0 to (m−1). 1 ≦ n + k ≦ (m−1). ]   The ratio of [weight of inorganic component derived from the compound (L)] / [total weight of organic component derived from the compound (L) and weight of organic component derived from the polymer (X)] is: The paper container of any one of Claims 1-4 which exists in the range of 20.0 / 80.0-80.0 / 20.0.   The paper container according to any one of claims 1 to 5, wherein the compound (P) is at least one selected from the group consisting of ethylenediamine, propylenediamine, and chitosan.   The paper container according to any one of claims 1 to 7, wherein 60 mol% or more of -COO- groups contained in the functional group of the polymer (X) are neutralized by the metal ions.   The paper container according to any one of claims 1 to 7, wherein the gas barrier laminate includes an unstretched heat-resistant polyolefin layer disposed inside the outermost layer.   The paper container according to claim 1, wherein the gas barrier laminate includes an inorganic layer formed by a vapor deposition method. The gas barrier laminate includes a substrate on which the gas barrier layer is laminated,
The paper container according to claim 9, wherein the inorganic layer is disposed between the base material and the layer having gas barrier properties. The gas barrier laminate includes at least two heat resistant polyolefin layers,
The paper container according to any one of claims 1 to 10, wherein the heat-resistant polyolefin layer is laminated on each of both surfaces of the layer having gas barrier properties.   The paper container according to claim 11, wherein the heat-resistant polyolefin layer is a polypropylene layer.   The paper container of any one of Claims 1-12 provided with the window part which does not contain the said paper layer and contains the layer which has the said gas-barrier property.

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