JP2000169652A - Ethylene-vinyl alcohol copolymer composition and laminated film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ethylene-vinyl alcohol copolymer composition containing a metal oxide, which can highly maintain excellent gas barrier properties even in an atmosphere of high temperature and high humidity. Offer things. The present invention comprises a metal oxide and an ethylene-vinyl alcohol copolymer, and comprises the following conditions (1) to (5):
It is a composition satisfying (4). (1) Si content based on all metal atoms in metal oxide =
20 mol% or more (2) Weight ratio of (metal atom) / (carbon atom) = 0.00
(3) The phase separation structure of the ethylene-vinyl alcohol copolymer phase and the metal oxide phase is (a) a co-continuous structure; or (b) the sea of the ethylene-vinyl alcohol copolymer and the average. Sea-island structure consisting of islands of a co-continuous structure in which an ethylene-vinyl alcohol copolymer phase is embedded in metal oxide particles having a particle diameter of 100 nm or less (4) Average pore diameter of sintered residue = 4.0 nm or less

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an ethylene-vinyl alcohol copolymer composition having excellent gas barrier properties, particularly excellent gas barrier properties under high temperature and high humidity, and to the ethylene-vinyl alcohol copolymer composition. The present invention relates to a laminated film containing a gas barrier layer.

[0002]

2. Description of the Related Art Packaging materials for packaging foods and various articles often require gas barrier properties, particularly oxygen barrier properties. This is to prevent effects such as oxidative deterioration of the package contents due to oxygen or the like. Particularly in the packaging of foods, there is a problem that the presence of oxygen causes microorganisms to propagate and the contents to spoil. For this reason,
A conventional packaging material is provided with a gas barrier layer for preventing the permeation of oxygen to prevent permeation of oxygen and the like.

As one type of the gas barrier layer, a metal foil or a vapor-deposited layer of a metal or a metal compound can be mentioned. In general, an aluminum foil, an aluminum vapor-deposited layer, a silicon oxide vapor-deposited layer, or the like is used. However, when these metals are used, there are drawbacks such as the invisible contents of the package and poor disposability.

[0004] Ethylene-vinyl alcohol copolymers are sometimes used as gas barrier layers because of their excellent gas barrier properties. Ethylene-vinyl alcohol copolymers have the advantage of being transparent and having few problems in terms of disposal, and are thus being used in a wider range of applications.

[0005] However, ethylene-vinyl alcohol copolymers exhibit high gas barrier properties in a dry state because they are crystallized by the hydrogen bond between the hydroxyl groups in the molecule to exhibit gas barrier properties.
It is known that in a state where moisture is absorbed by water vapor or the like in an atmosphere, the hydrogen bond is loosened and the gas barrier property tends to be reduced. Therefore, it is difficult for the ethylene-vinyl alcohol copolymer to exhibit high gas barrier properties even at high temperature and high humidity.

One of the methods for reducing the hygroscopicity of the ethylene-vinyl alcohol copolymer is to increase the content of ethylene units. However, this method involves a decrease in the content of vinyl alcohol units. Gas barrier performance tends to be impaired. Further, a crosslinked modified ethylene-vinyl alcohol copolymer having a crosslinking property such as a silyl group-modified ethylene-vinyl alcohol copolymer may be crosslinked, or the ethylene-vinyl alcohol copolymer may be γ-vinyl alcohol.
A crosslinked structure is introduced by reacting with a coupling agent such as glycidoxypropyltrimethoxysilane or by subjecting a crosslinkable vinyl carboxylate copolymer such as an ethylene-vinyl acetate copolymer to a saponification / crosslinking reaction. In such a case, it is possible to improve the moisture resistance, but it is undeniable that the gas barrier property tends to decrease. The cause of the gas barrier property decrease is based on a difference in crosslink density between a position near the crosslink point and a position relatively far from the crosslink point. It is considered that such a local void is sometimes referred to as a pinhole), which becomes a path for oxygen. Therefore, in these methods, there is a limit to exhibiting a high gas barrier property under both low humidity and high humidity in the ethylene-vinyl alcohol copolymer.

On the other hand, metal oxides such as silicon alkoxides are polycondensed in the presence of an organic polymer using a so-called sol-gel method, so that the metal oxide is relatively finely dispersed in the organic polymer. It has been proposed to prepare certain organic / inorganic composites. However, the composites obtained by these methods, even when mixed fairly homogeneously, are in most cases heterogeneous microscopically and consequently opaque. For example, JP-A-9-278968 and JP-A-8-993
No. 90, for example, in order to obtain an ethylene-vinyl alcohol copolymer material having improved water resistance, ethylene-vinyl by polycondensation of a metal alkoxide in the presence of an ethylene-vinyl alcohol copolymer Although a method for preparing a composition of an alcohol copolymer and a metal oxide has been proposed, a slight increase in the preparation stage due to the high crystallinity of the starting ethylene-vinyl alcohol copolymer has been proposed. Micro phase separation occurs.

[0008]

According to the study of the present inventors, it has been found that an ethylene-vinyl alcohol copolymer obtained by the above-mentioned preparation method using the ethylene-vinyl alcohol copolymer or a modified product thereof as a starting material is mixed with a metal. In the composition with the oxide, the dispersion state and / or the homogeneity are still insufficient as described above, so that not only the transparency tends to be poor, but also it is considered to be caused by pinhole generation under high humidity. Insufficient moisture resistance in gas barrier performance was found.

An object of the present invention, however, is to provide an ethylene-vinyl alcohol copolymer composition containing a metal oxide, which highly retains excellent gas barrier properties even in an atmosphere of high temperature and high humidity. To provide a composition that can be used. Another object of the present invention is to provide a material suitable for a packaging material, having such a composition as a gas barrier layer.

[0010]

The present inventors have conducted intensive studies to solve the above-mentioned problems, and as a result, have found that metal oxide-containing ethylene-vinyl resins satisfying specific conditions in micro phase separation structure, composition ratio and the like. The present inventors have found that the above problems can be solved by providing an alcohol copolymer composition and a laminated film using the same, and have completed the present invention.

That is, the present invention firstly provides a composition comprising a metal oxide and an ethylene-vinyl alcohol copolymer,

(1) The content of silicon atoms on the basis of all metal atoms in the metal oxide is 20 mol% or more;

(2) The ratio Wm / Wc of the weight Wm of the metal atom derived from the metal oxide contained in the composition to the weight Wc of the carbon atom contained in the composition is 0.001 to 0.001. 3.
0, and

(3) (a) the phase comprising the ethylene-vinyl alcohol copolymer and the phase comprising the metal oxide each form a co-continuous structure, or (b) the phase comprising the ethylene-vinyl alcohol copolymer The phase composed of the polymer and the phase composed of the metal oxide form a sea-island structure, and the sea component is composed of an ethylene-vinyl alcohol copolymer, and the average particle diameter of the island component composed of the metal oxide is 100 nm or less. It has a form of a co-continuous structure in which a phase made of an ethylene-vinyl alcohol copolymer has entered the particles, and

(4) BE for sintering residue at 500 ° C.
The average pore diameter determined by the T method is 4.0 nm or less;

An ethylene-vinyl alcohol copolymer composition characterized by the following:

Further, the present invention provides, secondly, the ethylene-
At least one of a vinyl alcohol copolymer composition
It is a laminated film containing two layers.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

The ethylene-vinyl alcohol copolymer composition of the present invention is an organic / inorganic composite composed of a specific metal oxide and an ethylene-vinyl alcohol copolymer. The above-mentioned metal oxide needs to have a silicon atom content of 20 mol% or more based on all metal atoms therein. If less than 20 mol%, ethylene-
Gas barrier properties and mechanical strength of the vinyl alcohol copolymer composition under high humidity are reduced. From the viewpoint of high gas barrier properties and high mechanical strength under high humidity, the content of silicon atoms on the same basis is preferably 50 mol% or more, and more preferably 80 mol% or more. When the metal oxide also contains a metal atom other than silicon, the metal atom other than silicon may be a divalent or more (more preferably 3
(Valent or tetravalent) metal atoms. As the metal oxide, silica, silica-titania, silica-
Alumina, silica-zirconia and the like are exemplified.

The ethylene-vinyl alcohol copolymer constituting the ethylene-vinyl alcohol copolymer composition of the present invention comprises an ethylene unit (—CH ₂ —CH ₂ —) and a vinyl alcohol unit (—CH ₂ —CH (OH) )-). The ethylene-vinyl alcohol copolymer includes a vinyl acetate unit, a vinyl propionate unit,
Although it may have a vinyl carboxylate unit such as a vinyl methylpropionate unit, from the viewpoint of the gas barrier properties of the ethylene-vinyl alcohol copolymer composition, from the viewpoint of the total of the vinyl alcohol unit and the vinyl carboxylate unit The ratio of the vinyl alcohol unit (degree of saponification) is preferably 80 mol% or more, more preferably 90 mol% or more, further preferably 95 mol% or more, and more preferably 99 mol% or more. Particularly preferred. In addition, the ethylene-vinyl alcohol copolymer in the present invention has a small proportion (preferably less than 10 mol% of all the structural units) as long as the effects of the present invention are not lost.
Α-olefins having 3 or more carbon atoms such as propylene and 1-butene; vinyl ethers such as methyl vinyl ether, ethyl vinyl ether and t-butyl vinyl ether;
Allyl alcohol; may contain a structural unit derived from another addition-polymerizable monomer such as vinyltrimethylsilane. However, in the ethylene-vinyl alcohol copolymer composition of the present invention, from the viewpoint of balance of gas barrier properties under both low humidity and high humidity conditions, ethylene based on all structural units in the ethylene-vinyl alcohol copolymer. The unit content is preferably in the range of 20 to 70 mol%, and more preferably in the range of 30 to 50 mol%.

The ethylene-vinyl alcohol copolymer may be a modified product such as a modified product of a silyl group and a modified product of boronic acid as long as the effect of the present invention is not impaired. However, since it is difficult to form pinholes, which serve as gas escape paths, in the ethylene-vinyl alcohol copolymer composition, the modification amount is preferably limited to 0.1 mol% or less, and 0.01 mol% or less. Is more preferable, and it is particularly preferable that it is unmodified. The molecular weight of the ethylene-vinyl alcohol copolymer in the present invention is not necessarily limited. Thus, the present invention encompasses a wide range of embodiments, from low molecular weight to high molecular weight, depending on the purpose. However, generally, the number average molecular weight is 5000
１００100,000, preferably 10,000 to 500
00 and its weight average molecular weight is 10,000.
~ 1,000,000, preferably 50,000 ~ 50
0000.

In the ethylene-vinyl alcohol copolymer composition of the present invention, the value of the ratio of the weight Wm of the metal atom derived from the metal oxide to the weight Wc of the carbon atom contained in the composition is contained. Wm / Wc is in the range of 0.001 to 3.0. When the value of Wm / Wc is less than 0.001, the gas-barrier property of the ethylene-vinyl alcohol copolymer composition at high temperature and high humidity becomes insufficient. Also,
When the value of Wm / Wc exceeds 3.0, ethylene-
The inherent flexibility of the vinyl alcohol copolymer composition is greatly impaired, the refractive resistance is insufficient in the form of a single-layer film or a laminated film with another substrate, and the gas barrier property tends to be significantly reduced after bending. From the viewpoint of the balance between gas barrier properties and flexibility, the value of Wm / Wc is 0.001 to 0.001.
It is preferably in the range of 1.0.

The above Wm and Wc can be determined based on the fluorescent X-ray analysis, the organic element analysis and the weight of the sintering residue as follows. That is, a sample obtained by sintering a sample of the ethylene-vinyl alcohol copolymer composition at 500 ° C. and then heat-treating it at 200 ° C. for 2 hours (a porous material composed of a metal oxide (however, ethylene-vinyl When a small amount of a metal-containing compound such as a clay mineral is present in the alcohol copolymer composition, an oxide derived from the metal component may be included))) is regarded as the weight of the metal oxide. Then, the residue is qualitatively determined for the metal element and the concentration thereof by X-ray fluorescence analysis. Based on the result and the weight of the metal oxide, the metal atom in the ethylene-vinyl alcohol copolymer composition is determined. The abundance (Wm) can be determined. Further, the analysis result of the sample before sintering of the ethylene-vinyl alcohol copolymer composition by the organic element analysis method is corrected based on the above-mentioned metal oxide amount and calculated, thereby obtaining the ethylene-vinyl alcohol copolymer composition. The abundance (Wc) of carbon atoms in a substance can be determined.

In the ethylene-vinyl alcohol copolymer composition of the present invention, the phase composed of the ethylene-vinyl alcohol copolymer and the phase composed of the metal oxide form a co-continuous structure or a specific sea-island structure. However, in the case of the sea-island structure, the sea component is made of an ethylene-vinyl alcohol copolymer, and the island component is made of a metal oxide and has an average particle diameter of 1
It is composed of a co-continuous structure in which a phase of an ethylene-vinyl alcohol copolymer is embedded in particles having a size of 00 nm or less. Such a phase separation structure can be confirmed by observing the ethylene-vinyl alcohol copolymer composition of the present invention with an electron microscope photograph. Also,
Similarly, the average particle size of the metal oxide particles of the island component in the case of the sea-island structure can be determined based on an electron micrograph. A composition having no phase-separated structure limited as described above has low gas barrier properties under high temperature and high humidity conditions. In the case of the sea-island structure, the average particle diameter of the island component particles is preferably 50 nm or less from the viewpoint of gas barrier properties under high temperature and high humidity conditions.
In addition, from the same viewpoint, a bicontinuous structure is more preferable.

In the ethylene-vinyl alcohol copolymer composition of the present invention, the sintering residue at 500 ° C.
It is necessary that the average pore diameter determined by the ET method is 4.0 nm or less. If the average pore diameter is larger than 4.0 nm, the gas barrier properties under high temperature and high humidity conditions will be low. The sintering residue of the ethylene-vinyl alcohol copolymer composition at 500 ° C. is obtained when the ethylene-vinyl alcohol copolymer composition is sintered at 500 ° C. and then heat-treated at 200 ° C. for 2 hours. Residue. When the ethylene-vinyl alcohol copolymer composition of the present invention is heated and calcined at 500 ° C., and then heat-treated at 200 ° C. for 2 hours, the phase of the metal oxide in the composition retains its shape, Since the phase composed of the ethylene-vinyl alcohol copolymer is completely burned, the resulting residue is a porous substance composed of a metal oxide. In the present invention, the pore size distribution of such a porous substance is measured using the BET method, and the average pore size is calculated based on the distribution. The average pore diameter is preferably 2.0 nm or less, more preferably 0.5 nm or less, and more preferably 0.3 nm or less, in that the gas barrier properties under high-temperature and high-humidity conditions are particularly good. Particularly preferred.

In the ethylene-vinyl alcohol copolymer composition of the present invention, a chemical bond may be partially formed between the ethylene-vinyl alcohol copolymer and the metal oxide. However, when this kind of chemical bond is formed, the average molecular weight of the ethylene-vinyl alcohol copolymer means the average molecular weight of the case where the chemical bond with the metal oxide is cut. .

The ethylene-vinyl alcohol copolymer composition of the present invention may be, if desired, a metal salt, a metal complex, a layered clay compound, an ethylene-vinyl alcohol copolymer as long as the effects of the present invention are not impaired. A polymer compound other than the above, a plasticizer, an antioxidant, an ultraviolet absorber, a flame retardant, and the like may be further contained. Examples of metal salts include:
Inorganic acid metal salts such as carbonate, hydrochloride and nitrate; organic acid metal salts such as oxalate and the like. Examples of the metal complex include an acetylacetonate metal complex, a cyclopentadienyl metal complex, and a cyano metal complex. Examples of the layered clay compound include natural smectite, lipophilic treated smectite, hydrophilic treated smectite, natural mica, lipophilic treated mica, talc, and the like. Examples of other polymer compounds include polyamide, polyolefin, and styrene-based block copolymer.

The ethylene-vinyl alcohol copolymer composition of the present invention can be produced by the following method. The method for producing the ethylene-vinyl alcohol copolymer composition of the present invention includes a metal alkoxide containing a silicon alkoxide or an oligomer thereof (hereinafter, a “metal alkoxide or a oligomer thereof containing a silicon alkoxide” is referred to as a “metal alkoxide”). System component)), using a solution (sol) containing a vinyl carboxylate polymer and an organic solvent to evaporate low-boiling substances including the organic solvent, and evaporating the metal in the same reaction system. By conducting the polycondensation reaction of the alkoxide or oligomer and the saponification reaction of the vinyl carboxylate polymer in parallel, a polyvinyl alcohol composition (gel or solid organic / inorganic composite) comprising a metal oxide and polyvinyl alcohol ) Manufacturing method (for example,
Polymer. Prep. Jpn., Vol. 45 (No. 5), pp. 907 (19
96) and Appl. Organometal. Chem., Vol. 12, No. 755
(Refer to page (1998))
abbreviated as “u-saponified sol-gel method”), a production method comprising using an ethylene-vinyl carboxylate copolymer instead of a vinyl carboxylate polymer. However, in order to produce the ethylene-vinyl alcohol copolymer composition of the present invention, the reaction is preferably performed so as to satisfy the following conditions (i) and (ii).

(I) As a metal alkoxide-based component, the content of silicon atoms based on all metal atoms is 2%.
Use at least 0 mol%

(Ii) The calculated value of the weight of the carbon atom in the ethylene-vinyl alcohol copolymer derived from the ethylene-vinyl carboxylate copolymer and the calculated value of the weight of the metal atom in the metal alkoxide-based component are respectively: Wc 'and W
When represented by m ′, the value of Wm ′ / Wc ′ is 0.001 to
The use ratio between the ethylene-vinyl carboxylate copolymer and the metal alkoxide-based component is set so as to fall within the range of 3.0.

Hereinafter, the above manufacturing method will be described in detail.

The metal alkoxide-based component used in the above production method includes silicon alkoxide, metal alkoxides other than silicon alkoxide, oligomers of metal alkoxides having units derived from silicon alkoxide, and oligomers of metal alkoxides having no units derived from silicon alkoxide. At least one component selected from the group consisting of silicon alkoxide and an oligomer of a metal alkoxide having a unit derived from silicon alkoxide. Since the metal alkoxide-based component is derived from the metal oxide contained in the ethylene-vinyl alcohol copolymer composition of the present invention, the desired silicon in the metal oxide in the obtained ethylene-vinyl alcohol copolymer composition is obtained. A metal alkoxide-based component having a silicon atom content (based on all metal atoms) substantially equal to the atom content (based on all metal atoms) may be used. Therefore, the metal alkoxide-based component used preferably has a silicon atom content of 20 mol% or more based on all metal atoms, more preferably 50 mol% or more, and more preferably 80 mol% or more. Those are particularly preferred.

The silicon alkoxide is preferably one having one silicon atom and having a chemical structure in which two, three or four alkoxy groups are bonded to a silicon atom. Here, the number of alkoxy groups is more preferably three or four, and particularly preferably four.
When the number of alkoxy groups is two or three, an alkyl group (eg, a methyl group), an aryl group (eg, a phenyl group), a halogen atom (eg, a chlorine atom), and the like are further bonded to the silicon atom. Examples of the alkoxy group include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, and a butoxy group. Specific examples of silicon alkoxide include tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane,
Examples include phenyltrimethoxysilane and chlorotrimethoxysilane.

The metal alkoxide other than the above silicon alkoxide has one or more (more preferably trivalent or tetravalent) metal atom such as titanium, aluminum and zirconium, and has one or more (more than one) metal atom. Preferably 2
(Preferably 3 or more, particularly preferably 3 or more) compounds having a chemical structure to which alkoxy groups are bonded. Specific examples of the alkoxy group include those exemplified above for the silicon alkoxide. The metal atom may have a substituent other than the alkoxy group, and examples of the substituent include an alkyl group (such as a methyl group), an aryl group (such as a phenyl group), and a halogen atom (such as a chlorine atom). . Specific examples of the metal alkoxide include alkoxytitanium compounds such as tetramethoxytitanium, tetraethoxytitanium, tetraisopropoxytitanium, and methyltriisopropoxytitanium; trimethoxyaluminum, triethoxyaluminum, triisopropoxyaluminum, and methyldiisopropoxy. Alkoxyaluminum compounds such as aluminum, tributoxyaluminum and diethoxyaluminum chloride; and alkoxyzirconium compounds such as tetraethoxyzirconium, tetraisopropoxyzirconium and methyltriisopropoxyzirconium.

The above-mentioned oligomers of metal alkoxides having units derived from silicon alkoxide include oligomers of the above-mentioned silicon alkoxides alone and co-oligomers of the above-mentioned silicon alkoxides with other metal alkoxides. Examples of the other metal alkoxide include titanium, aluminum, zirconium and the like.
One or more (more preferably trivalent or tetravalent) metal atoms
Compounds having a chemical structure in which one or more (more preferably two or more, particularly preferably three or more) alkoxy groups are bonded thereto are preferred. Oligomers of metal alkoxides having units derived from silicon alkoxides can be produced by hydrolyzing / polycondensing a silicon alkoxide alone or in a mixture with other metal alkoxides by a known method, and having a low molecular weight hydroxyl group. It is preferably an oligomer containing. Preferred specific examples of the oligomer of a metal alkoxide having a unit derived from a silicon alkoxide include a silanol group-containing tetramethoxysilane dimer or an oligomer of a trimer or more thereof, and a silanol group-containing tetraethoxysilane dimer or a trimer thereof The above oligomers, silanol-terminal-modified oligodimethylsiloxane, and the like can be mentioned. Although the degree of polymerization is not necessarily limited, it is preferably in the range of 2 to 25, and more preferably in the range of 2 to 10.

Examples of the metal alkoxide oligomer having no unit derived from silicon alkoxide include divalent or higher (more preferably trivalent or tetravalent) metal atoms such as titanium, aluminum and zirconium.
One or two compounds having a chemical structure in which one or more (excluding silicon atoms) is bonded to one or more (more preferably two or more, particularly preferably three or more) alkoxy groups The above is preferably a low molecular weight hydroxyl group-containing oligomer which can be produced by hydrolysis and polycondensation by a known method. Preferred specific examples of the oligomer of a metal alkoxide having no unit derived from silicon alkoxide include a hydroxyl group-containing tetraisopropoxy titanium dimer or an oligomer of a trimer or more thereof. Although the degree of polymerization is not necessarily limited, it is preferably in the range of 2 to 25, and more preferably in the range of 2 to 10.

The ethylene-vinyl carboxylate copolymer used in the above production method is a copolymer mainly composed of ethylene units and vinyl carboxylate units. Since the ethylene-vinyl alcohol copolymer is derived from the ethylene-vinyl alcohol copolymer contained in the ethylene-vinyl alcohol copolymer composition of the present invention, the resulting ethylene-vinyl alcohol copolymer composition contains Depending on the desired chemical structure, molecular weight, etc. of the ethylene-vinyl alcohol copolymer, it is preferable to use a suitable one as appropriate.
As the ethylene-vinyl carboxylate copolymer, for example, a binary copolymer such as an ethylene-vinyl acetate copolymer or an ethylene-vinyl propionate copolymer is preferable,
It may contain a small proportion of units or modified portions derived from other comonomers. Although it is possible to use a partially saponified ethylene-carboxylate copolymer, the degree of saponification is limited to 10 mol% or less because the composition of the present invention is easily obtained. Preferably, 1
It is more preferable to keep the amount to not more than mol%. Further, the average molecular weight of the ethylene-vinyl carboxylate copolymer used is not particularly limited, but in general, the number-average molecular weight of the ethylene-vinyl alcohol copolymer obtained by saponifying it is generally used. 5000-100
000, preferably in the range of 10,000 to 50,000, and the weight average molecular weight of the ethylene-vinyl alcohol copolymer is generally 10,000 to 1
000000, preferably 50,000-5000
Those that fall within the range of 00 are used.

With respect to the ethylene-vinyl carboxylate copolymer and the metal alkoxide component used in the reaction in the above-mentioned production method, the value of Wm '/ Wc' defined above falls within the range of 0.001 to 3.0. Thus, it is preferable to set the usage ratio of both. Since the value of Wm ′ / Wc ′ is usually close to the value of Wm / Wc in the obtained ethylene-vinyl alcohol copolymer composition, the value of Wm ′ / Wc ′ is 0.001 to 1.0. Is more preferably set to be within the range.

The reaction in the above-mentioned production method is such that the above-mentioned polycondensation reaction of the metal alkoxide-based component and the saponification reaction of the ethylene-vinyl carboxylate copolymer proceed in parallel in the same system. Is in sit
This is based on a known reaction technique in the u-saponification sol-gel method. The polycondensation reaction of the metal alkoxide-based component produces a macromolecularized metal oxide. When a compound containing an alkoxy group or an oligomer containing an alkoxy group is used, such as a metal alkoxide, the alkoxy group is used. It proceeds by a dehydration condensation reaction via a hydrolysis reaction that changes into a hydroxyl group, but when an oligomer containing a hydroxyl group is used, it may proceed only by a dehydration condensation reaction without going through a hydrolysis reaction. Either case is applicable. On the other hand, the saponification reaction of the ethylene-vinyl carboxylate copolymer produces an ethylene-vinyl alcohol copolymer, and the acyloxy group derived from the vinyl carboxylate unit in the ethylene-vinyl carboxylate copolymer becomes a hydroxyl group. At the same time, carboxylic acid compounds (depending on the type of organic solvent and catalyst used, but usually one or more compounds of carboxylic acids, carboxylic esters and carboxylate salts) are converted to secondary compounds. Live. In addition, in the ethylene-vinyl alcohol copolymer composition obtained by this simultaneous reaction, a covalent bond may be partially formed between the ethylene-vinyl alcohol copolymer and the metal oxide. Presumed.

In the above reaction, in addition to the acid catalyst known in the in situ saponification sol-gel method, various catalysts known in the general sol-gel method can be used. Examples of usable catalysts include acidic catalysts such as hydrochloric acid, sulfuric acid, p-toluenesulfonic acid, benzoic acid, acetic acid, lactic acid, and carbonic acid; and ammonia, sodium hydroxide, magnesium hydroxide, potassium hydroxide, triethylamine, ethylenediamine and the like. Basic catalysts can be mentioned, and these may be used alone or in combination. In general,
It is preferable to use an acidic catalyst, and it is more preferable to use a combination of an acidic catalyst and a basic catalyst. However, when a low molecular weight hydroxyl group-containing oligomer that has been hydrolyzed and polycondensed to some extent in advance is used as the metal alkoxide-based component, it is preferable to use a basic catalyst. The amount of the catalyst used is not strictly limited, but the number of moles of the alkoxy group in the metal alkoxide component used and the acyl group derived from the vinyl carboxylate unit of the ethylene-vinyl carboxylate copolymer used 0.001 to 1 mole of the sum (total mole number) of
Preferably it is in the range of 0.1 gram equivalent,
More preferably, it is in the range of from 0.01 to 0.05 gram equivalent.

In the reaction in the above production method, a solution (sol) obtained by dissolving an ethylene-vinyl carboxylate copolymer and a metal alkoxide-based component in an organic solvent is used.
The organic solvent used at this time is not particularly limited as long as it can sufficiently dissolve both the ethylene-vinyl carboxylate copolymer and the metal alkoxide-based component, but methanol, ethanol, propanol, butanol, and the like. It is preferable to use alcohols; amides such as dimethylformamide and dimethylacetamide; and sulfoxides such as dimethylsulfoxide alone or in combination of two or more. Among them, methanol, ethanol, dimethylsulfoxide and the like are particularly preferable. The use amount of the organic solvent is not necessarily limited, but is preferably in the range of 20 to 2,000 parts by weight with respect to 100 parts by weight of the total weight of the ethylene-vinyl carboxylate copolymer and the metal alkoxide-based component. And more preferably in the range of 100 to 1000 parts by weight. Vinyl carboxylate units in the ethylene-vinyl carboxylate copolymer used in the organic polymer in the reaction system (the final product derived from the saponification reaction of the ethylene-vinyl carboxylate copolymer used or an intermediate thereof) When it is desired to reduce the residual ratio of acyl groups derived from the above, a uniform solvent containing 5% by weight or more of an organic solvent having an affinity for a predetermined ethylene-vinyl alcohol copolymer is suitably used.

In the above reaction, if necessary, water may be present in the reaction system. For example, when using a metal alkoxide having an alkoxy group or an oligomer having an alkoxy group as a metal alkoxide-based component,
The progress of the hydrolysis reaction of the alkoxy group requires the presence of water. The amount of water used is not necessarily limited, and as described above, can be appropriately set in consideration of the metal alkoxide-based component to be used, the type of catalyst, and the like. It is preferable to select from a range of 1.5 to 4.0 times the mole of the alkoxy group in the metal alkoxide component. When a water-containing component such as hydrochloric acid is used, the amount of water to be used should be determined in consideration of the amount of water introduced by the component.

The ethylene-vinyl alcohol copolymer composition of the present invention may contain a metal salt, a metal complex, a layered clay compound, another polymer compound, a plasticizer, an antioxidant, an ultraviolet absorber,
When it is desired to include other components such as a flame retardant, it is preferable to add an optional component to be contained in a solution containing the ethylene-vinyl carboxylate copolymer and the metal alkoxide-based component. preferable. Note that the addition of a coupling agent such as γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, and the like in the resulting ethylene-vinyl alcohol copolymer composition high temperature·
The use of such a coupling agent often gives better results because it may hinder the improvement of gas barrier properties under high humidity conditions. However, when the above-mentioned metal salts, metal complexes, layered clay compounds and the like are blended, the use of a coupling agent may be effective in improving their dispersibility. Therefore, when a coupling agent is used, it is desirable to keep the amount to 0.1 mol% or less, more preferably 0.01 mol% or less, based on the metal component in the metal alkoxide-based component used.

In the reaction in the above production method, the degree of saponification of the resulting ethylene-vinyl alcohol copolymer is preferably at least 80 mol%, more preferably at least 90 mol%, further preferably at least 95 mol%, particularly preferably at least 95 mol%. Continue until 99 mol% or more. In order to increase the degree of saponification in this way, it is preferable to carry out the reaction while evaporating the low-boiling substances at least at a later stage. As the low-boiling point compound, when an excess amount of water such as an organic solvent, the above-mentioned carboxylic acid-based compound by-produced by saponification of a vinyl carboxylate polymer, and water by-produced by polycondensation of a metal alkoxide-based component is added. Includes excess water and the like. In order to highly increase the degree of saponification, for example, the amount of the solvent used is adjusted so that the water content in the reaction system is 3% by weight or less, more preferably 1% by weight or less, and further preferably 0.5% by weight or less. Adjusting the amount of water in the reaction system within the range of 30 to 100 mol%, more preferably 40 to 100 mol%, based on the alkoxy group derived from the metal alkoxide component.
~ 75 mol% in the range, and, as a metal alkoxide-based component, an alkoxy group and a hydroxyl group,
1 / 0.5 to 1 in molar ratio of alkoxy group / hydroxyl group
/2.0, more preferably 1 / 0.8-1 /
It is desirable to employ one or more conditions of using a metal alkoxide or an oligomer thereof contained in the range of 1.25.

The ethylene-vinyl alcohol copolymer composition obtained has an excellent transparency and good color tone (ie, does not cause coloring such as brown, black, etc.). Ethylene in the polymer (the final product or its intermediate derived by the saponification reaction of the ethylene-vinyl carboxylate copolymer used)
In the region where the residual ratio X of the acyl group derived from the vinyl carboxylate unit in the vinyl carboxylate copolymer is 40 mol% or less, the carboxylic acid-based compound is represented by the following formula:

[0046]

[Equation 1] Y ≦ 0.9X + 5.0 (I)

(In the formula, X represents the residual ratio (unit: mol%) of the above acyl group, and Y represents the acyl group derived from the vinyl carboxylate unit in the ethylene-vinyl carboxylate copolymer used. (Represents the relative ratio (unit: mol%) of the amount of the carboxylic acid compound contained in the reaction system based on the initial amount.)

It is desirable to carry out the reaction while removing it from the reaction system (the reaction is in a solution state at the beginning of the reaction, but in a solid state at the end of the reaction) so as to satisfy the following. The residual ratio X (mol%) of the acyl group of the organic polymer in the reaction system was determined based on the organic weight contained in the reaction system based on the initial amount of the acyl group in the ethylene-vinyl carboxylate copolymer used. It is a relative ratio of the amount of the acyl group in the coalescence, and the degree of saponification of the organic polymer by only the saponification reaction from the used ethylene-vinyl carboxylate copolymer is represented by Z (mol%), and is represented by 100-Z. be able to.

The above formula (I) qualitatively indicates that the content of the by-produced carboxylic acid compound in the reaction system must be further reduced as the reaction proceeds, that is, the carboxylic acid This means that removal of the system compound from the reaction system needs to be performed more strictly. For the purpose of satisfying the formula (I), after the point in time during the reaction (the point when the residual ratio X of the acyl group in the organic polymer in the reaction system becomes 40 mol% or before), the reaction system It is preferable to promote the evaporation of the carboxylic acid compound by performing a reaction under reduced pressure conditions controlled based on the quantitative value while quantifying the carboxylic acid compound present in the carboxylic acid compound. However, since the carboxylate salt cannot be removed by evaporation among the carboxylic acid compounds, it is preferable to suppress the formation of the carboxylate salt so that the carboxylic acid and / or the carboxylic acid ester can be preferentially formed.

When the pressure of the reaction system is reduced to remove the carboxylic acid compound from the reaction system, the pressure condition is expressed by the formula (I)
May be adjusted appropriately so as to satisfy the following. However, if the pressure is lowered unnecessarily, the evaporation of the organic solvent may be too early to obtain a uniform composition, or the composition may not be obtained in a predetermined shape due to foaming. It is preferable to gradually lower the pressure while observing the state of the reaction system. From these facts, it is generally preferable that the pressure condition at the time of pressure reduction is selected from the range of 0.01 to 700 mmHg in absolute pressure, more preferably from the range of 0.1 to 400 mmHg.

The residual ratio X of the acyl group and the abundance Y of the carboxylic acid compound can be determined by quantitative analysis using a small amount of a sample collected from the reaction system at any time during the reaction. That is, the residual ratio X of the acyl group is, for example, a value obtained by quickly drying a small amount of a sample collected from a liquid (sol), gel or solid reaction system at a temperature of about 40 ° C. under reduced pressure. (Acetyl group, propionyl group, etc.) was quantitatively analyzed by a diffuse reflection method using FT-IR for the composition containing the organic polymer of The determination can be made on the basis of the analysis value of the acyl group obtained by quantitatively analyzing the merging in the same manner. Further, the abundance Y of the carboxylic acid-based compound can be determined by, for example, dissolving a small amount of a sample collected from a liquid (sol), gel, or solid reaction system in deuterated methanol, using ¹³ C—N
Using an MR, quantitative analysis of all acyl groups (acetyl group, propionyl group, etc.) of the organic polymer in the course of the reaction and the carboxylic acid compound produced as a by-product was carried out. The relative ratio (mol%) based on the analysis value of the acyl group of the ethylene-vinyl carboxylate copolymer obtained by quantitatively analyzing the copolymer in the same manner was calculated. It can be determined by obtaining the difference from the residual ratio X of the group. Even when it is desired to satisfy the above formula (I), in a region where the residual ratio X of the acyl group in the organic polymer is 40 mol% or less, the residual ratio X and the abundance Y of the carboxylic acid compound are present. It is not always necessary to always determine It is desirable that the formula (I) is always satisfied in a region where the acyl group residual ratio X is 40 mol% or less, but the condition may be out of order as long as it is instantaneous. Therefore, as long as a condition that satisfies the above formula (I) with a certain margin is adopted, it is practical to determine both of them at appropriate time intervals and to control the pressure condition as necessary. .

The temperature of the reaction system in the reaction in the above production method is not necessarily limited, but is usually 20 to
It is in the range of 100C, preferably in the range of 40-60C. The reaction time varies depending on the reaction conditions such as the amount and type of the catalyst. The operation may be continued until a predetermined degree of saponification is achieved within a range of 24 hours. The atmosphere of the reaction system is not necessarily limited, and conditions such as an air atmosphere and a nitrogen stream can be adopted.

In the reaction in the above-mentioned production method, the initial stage of the reaction (the stage before the acyl group residual ratio X reaches 40 mol%)
It is preferable to carry out the reaction while suppressing the evaporation of the organic solvent and the like, and evaporating the organic solvent, the carboxylic acid compound and the like in the latter half of the subsequent reaction. For this purpose, it is preferable to carry out the reaction under normal pressure or under pressure in the initial stage of the reaction, and to shift to a reduced pressure system in the latter stage of the reaction.

In the reaction in the above production method, the metal alkoxide-based component, the ethylene-vinyl carboxylate copolymer, the organic solvent and, if necessary, other components (catalyst,
The reaction is started using a solution (sol) containing water, etc.). Changes during the reaction, ethylene-
A gel-like organic / inorganic composite containing a vinyl alcohol copolymer, a metal oxide and a small amount of an organic solvent is formed, and finally, a solid composition is formed. When the reaction system is liquid, stirring may be performed.

In the above-mentioned production method, the heat treatment may be performed at the latter stage of the reaction and / or after the completion of the reaction.
It is preferably in the range of 50 ° C.,
More preferably, it is in the range of ° C.

In the above reaction, the ethylene-vinyl alcohol copolymer composition is produced in a predetermined shape such as a film or sheet by placing the solution at the beginning or during the reaction in a mold having a predetermined shape. can do. A gel-like organic / inorganic composite comprising an ethylene-vinyl alcohol copolymer and a metal oxide in a state where an organic solvent remains is spun according to a known method, and then the reaction is driven to obtain an ethylene-vinyl alcohol. The alcohol copolymer composition can be manufactured in a fibrous form.
Further, after the reaction at the beginning or in the middle of the reaction is impregnated into a substrate made of a fiber aggregate such as a fabric, by performing the reaction, the ethylene-vinyl alcohol copolymer composition is impregnated into the fiber aggregate base. Can be produced.

Further, in the above reaction, after forming a film comprising a solution at the beginning or in the middle of the reaction on a substrate having a predetermined shape, the reaction is carried out to form a layer comprising the ethylene-vinyl alcohol copolymer composition. Can be produced. The substrate is not necessarily limited and includes, for example, polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate, polybutylene terephthalate and polyethylene naphthalate; polyamides such as nylon 6 and nylon 66; A molded article made of a polymer or the like can be employed. In order to form a film made of the solution on the substrate, a known method such as a casting method, a dipping method, a roll coating method, a spray method, and a screen printing method can be adopted. The application of the solution to the substrate may be repeated a plurality of times, whereby the thickness of the composition layer formed after the reaction can be adjusted. The thickness of the composition layer in the laminate is not necessarily limited, but may be 0.01 to 20.
0 μm, preferably 0.01 to 50 μm.
More preferably, it is within the range of μm.

[0058] Among the laminates thus produced, the laminated film containing at least one layer comprising the ethylene-vinyl alcohol copolymer composition of the present invention includes the ethylene-vinyl alcohol copolymer of the present invention. The characteristics of the united composition are particularly effectively exhibited. The substrate of the laminated film is not necessarily limited,
From the viewpoint of strength and the like, biaxially stretched polypropylene film,
A stretched resin film such as a biaxially stretched polyethylene terephthalate film or a biaxially stretched nylon 66 film is preferred. The laminated film may have two or more layers made of a base material, and may have a layer made of paper as at least one of the base material layers. The total thickness of the laminated film is not necessarily limited, but is generally in the range of 0.01 to 0.3 mm. The laminated film can be processed into a three-sided seal bag, a four-sided seal bag, a gazette-like bag, a standing pouch, a pillow packaging bag, and the like by an adhesive method such as a heat sealing method. It can be used as a packaging material such as a packaging material.

[0059]

EXAMPLES The method of the present invention will be described in more detail with reference to the following examples, but it should not be construed that the present invention is limited thereto.

The measurement or evaluation in the following examples and the like was performed by the following methods (1) to (8).

(1) Amount of acyl group: Ethylene-vinyl carboxylate copolymer (ethylene-vinyl acetate copolymer, ethylene-vinyl propionate copolymer, etc.) and the finally obtained composition For the corresponding ethylene-vinyl alcohol copolymer, the acyl group (acetyl group or propionyl group) was quantitatively analyzed by FT-IR ("FTIR8200" manufactured by Shimadzu Corporation) by a diffuse reflection method. For the acyl group-containing organic polymer in the course of the reaction, a small amount of a sample is collected from the liquid (sol), gel or solid reaction system, dried at 40 ° C. under reduced pressure, and dried in the same manner. Was quantitatively analyzed. The residual ratio of acyl groups in the organic polymer during the reaction and the final ethylene-vinyl alcohol copolymer (unit: mol%)
Was calculated based on the amount of these acyl groups.

(2) Carboxylic acid compound amount: Simultaneously with the above-mentioned measurement of the acyl group amount, a small amount of a sample is sampled from a liquid (sol), gel or solid reaction system and deuterated methanol is added. Dissolved in 100 MHz ¹³ C-NMR
(JNM-LA400 / WB, manufactured by JEOL) using an organic polymer in the course of the reaction and a carboxylic acid-based compound (acetic acid and its derivatives (esters, salts, etc.) or propionic acid and its derivatives) produced as a by-product. All of the acyl groups (acetyl group, propionyl group, etc.) were quantitatively analyzed. With respect to the analysis value, a relative ratio (mol) based on the analysis value of the acyl group of the ethylene-vinyl carboxylate copolymer obtained by quantitatively analyzing the ethylene-vinyl carboxylate copolymer used in the same manner. %) And the difference between the relative ratio and the above-mentioned residual ratio of acyl groups was determined to determine the amount (unit: mol%) of the carboxylic acid compound in the reaction system.

(3) Wm / Wc ratio of the composition: ethylene-
A sample of the vinyl alcohol copolymer composition was sintered at 500 ° C. and then heat-treated at 200 ° C. for 2 hours, and the weight of the residue obtained was regarded as the weight of the metal oxide. Then, the residue is qualitatively determined for the metal element and the concentration thereof by X-ray fluorescence analysis. Based on the result and the weight of the metal oxide, the metal atom in the ethylene-vinyl alcohol copolymer composition is determined. The abundance (Wm) was determined. Further, the analysis result of the sample before sintering of the ethylene-vinyl alcohol copolymer composition by the organic element analysis method is corrected based on the above-mentioned metal oxide amount and calculated, thereby obtaining the ethylene-vinyl alcohol copolymer composition. The abundance (Wc) of carbon atoms in the product was determined. The Wm / Wc ratio was calculated based on the values of Wm and Wc.

(4) Morphology of the composition: By observing the obtained ethylene-vinyl alcohol copolymer composition with an electron microscope photograph, the microphase separation structure between the ethylene-vinyl alcohol copolymer phase and the metal oxide phase was obtained. It was confirmed. In addition, the average particle diameter of the metal oxide particles of the island component in the case of the sea-island structure was similarly determined based on an electron micrograph.

(5) Average pore size of sintered residue: The obtained ethylene-vinyl alcohol copolymer composition was sintered at 500 ° C. and then heat-treated at 200 ° C. for 2 hours. The pore size distribution was measured using the method, and the average pore size was calculated based on the distribution.

(6) Gas barrier property: The obtained film-form ethylene-vinyl alcohol copolymer composition or laminated film was measured for oxygen permeation amount ("MOCON OX-TRAN 2/20" manufactured by Modern Control Co., Ltd.).
The oxygen permeation amount (unit: cc ·) under the conditions of temperature 20 ° C and humidity 65% RH, temperature 60 ° C and humidity 100% RH and temperature 90 ° C and humidity 100% RH, respectively. ^{20μm / m 2 · 24hr · atm} ) was measured (oxygen pressure: 2.
5 kg / cm ² ). It can be determined that the smaller the oxygen permeation amount under the condition of the temperature of 20 ° C. and the humidity of 65% RH, the better the gas barrier property under the normal condition. In addition, temperature 20
60 ° C., humidity 65% RH, temperature 60
° C, humidity 100% RH or temperature 90 ° C, humidity 1
It can be determined that the smaller the relative value of the oxygen permeation amount under the condition of 00% RH and the value is closer to 1, the less likely the gas barrier property is to be affected by environmental changes such as humidity.

(7) Flexibility: Regarding the flexibility of the obtained film-like ethylene-vinyl alcohol copolymer composition or laminated film, a 0.1 mm-thick dumbbell-shaped test piece was prepared and subjected to a tensile test. Machine (Shimadzu “AG5”
000 "), the tensile elongation (unit:%) was measured under the conditions of a temperature of 20 ° C., a humidity of 40% RH and a strain rate of 50 cm / min, respectively, and the ethylene-vinyl alcohol copolymer alone (number average molecular weight : 26000; weight average molecular weight: 92000; ethylene unit content: 44 mol%; saponification degree: 99.9 mol%), the value of which is in the range of 50 to 150% based on the tensile elongation similarly measured. In this case, “good (」) ”,“ 33% or more and less than 50% (half) ”or“ more than 150% and 167% or less ”is“ slightly poor (△) ”, and“ less than 33% or 167 ” %, It was judged as "poor (x)".

(8) Appearance: The transparency and color of the obtained film-form ethylene-vinyl alcohol copolymer composition or laminated film were visually confirmed. The case of colorless and transparent was judged as “good (○)”, and the case of opaque or colored was judged as “bad (x)”.

Example 1 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight:
60000; weight average molecular weight: 400,000) 16.5
After dissolving parts by weight in 200 parts by weight of methanol, 1.26 parts by weight of tetramethoxysilane, 0.5 parts by weight of distilled water and 1.0 parts by weight of 1N (normal) -hydrochloric acid were added to prepare a sol. Was reacted at 60 ° C. for 4 hours while stirring.
The obtained sol is transferred to a flat-bottomed polytetrafluoroethylene (Dupont “Teflon”) container so as to have a height of 2 mm, and then the upper open part of the container is made of a polyvinylidene chloride film (Asahi Kasei Kogyo “Saran Wrap”). And reacted at 60 ° C. for another 4 hours. Thereafter, a hole was formed in the coated film with a needle so that the porosity was 1% based on the area of the coated film, and the reaction was continued at 60 ° C. for 4 hours. Next, when the residual ratio of acyl groups (residual ratio of acetyl groups in this example) in the organic polymer in the system reached 60 mol%, the pressure in the reaction system was reduced (pressure: 100 mmHg).
The reaction was carried out at 60 ° C. while controlling the amount of the carboxylic acid compound (acetic acid compound in this example) in the reaction system to satisfy the above formula (I). After 4 hours, the pressure was changed to 20 mmHg, and the reaction was continued at 40 ° C for 4 hours.
Thus, a colorless and transparent film composed of the ethylene-vinyl alcohol copolymer / silica composite was obtained. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. Table 1 shows the obtained results.
Shown in In Table 1, the amount of the carboxylic acid compound present in the reaction system is also shown for each 10 mol% residual ratio at the stage where the acyl group residual ratio is 45 mol% or less.

<Examples 2 to 6> In Example 1, the ethylene-vinyl acetate copolymer (ethylene unit content: 32
Mol% ;; number average molecular weight: 60000; weight average molecular weight: 400,000). A combination of 16.5 parts by weight and 1.26 parts by weight of tetramethoxysilane was mixed with an ethylene-vinyl acetate copolymer (ethylene unit content: 32 Mol%; number average molecular weight: 35,000; weight average molecular weight: 20,000
0) Combination of 15.6 parts by weight and 2.5 parts by weight of tetramethoxysilane (Example 2), ethylene-vinyl acetate copolymer (ethylene unit content: 44 mol%; number average molecular weight: 20,000; weight) (Average molecular weight: 50,000) 11.
A combination of 4 parts by weight and 7.6 parts by weight of tetramethoxysilane (Example 3), an ethylene-vinyl acetate copolymer (ethylene unit content: 44 mol%; number average molecular weight: 420)
00; weight average molecular weight: 150,000) in combination with 8.2 parts by weight of tetraethoxysilane (17.3 parts by weight) (Example 4), ethylene-vinyl propionate copolymer (ethylene unit content: 38 mol%; Number average molecular weight: 430
00; weight average molecular weight: 200000) in combination with 4.1 parts by weight of tetramethoxysilane (Example 5), or ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; Number average molecular weight: 3500
0; weight average molecular weight: 200000) The reaction was carried out in the same manner except that the combination was changed to 15.6 parts by weight of methyltrimethoxysilane and 2.03 parts by weight of methyltrimethoxysilane (Example 6). A colorless and transparent film composed of the polymer / silica composite was obtained. However, the transition of the amount of the carboxylic acid compound during the reaction was as shown in Table 1. About the obtained film, Wm
Table 1 also shows the results of the determination of the / Wc ratio, the morphology observation, the measurement of the average pore size of the sintered residue, the evaluation of gas barrier properties, and the evaluation of flexibility.

Comparative Example 1 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight:
(35,000; weight-average molecular weight: 200000) was dissolved in a mixed solution consisting of 150 parts by weight of methanol and 50 parts by weight of distilled water, and then 24.0 parts by weight of tetramethoxysilane and 2.0 parts by weight of 1N hydrochloric acid. A sol was prepared by adding the mixture, and the mixture was reacted at 60 ° C. for 4 hours while stirring. The obtained sol is transferred to a flat-bottomed polytetrafluoroethylene (Dupont “Teflon”) container so as to have a height of 2 mm, and then the upper open part of the container is made of a polyvinylidene chloride film (Asahi Kasei Kogyo “Saran Wrap”). And reacted at 60 ° C. for another 4 hours. Thereafter, a hole was formed in the coating film with a needle so that the porosity was 1% based on the coating film area, and the reaction was continued at 80 ° C. for further 8 hours. Next, the inside of the reaction system was evacuated (pressure: 20 m).
mHg), and the reaction was continued at 40 ° C for 4 hours. Thus, a colorless and transparent film composed of the ethylene-vinyl alcohol copolymer / silica composite was obtained. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. Table 1 shows the obtained results. In Table 1, the amount of the carboxylic acid compound present in the reaction system is also shown for each 10 mol% residual ratio at the stage where the acyl group residual ratio is 45 mol% or less.

[0072]

[Table 1]

The "amount of the carboxylic acid compound" in Table 1 means the amount of the by-produced carboxylic acid compound in the reaction system by the amount of acyl in the ethylene-vinyl carboxylate copolymer used. It is expressed as a mole fraction based on the group. Further, the "acyl group residual ratio" refers to the residual amount of the acyl group in the organic polymer in the reaction system or the ethylene-vinyl alcohol copolymer in the finally obtained composition, and the ethylene-carboxylic acid used It is represented by a mole fraction based on the acyl group in the vinyl copolymer.
“Cocontinuous” in the column of “morphology” means a bicontinuous structure composed of an ethylene-vinyl alcohol copolymer phase and a metal oxide phase. In addition, “sea island” in the same column indicates that the sea component is ethylene-unless otherwise specified.
It means a sea-island structure composed of a vinyl alcohol copolymer phase and a co-continuous structure in which the ethylene-vinyl alcohol copolymer phase is embedded in particles composed of a metal oxide as an island component. However, “sea-island (island: EVOH)” in Comparative Example 1 means that the island component has an ethylene-vinyl alcohol copolymer phase and the sea component has a sea-island structure including a metal oxide phase. Further, in the item of “gas barrier properties” in Table 1, “20 ° C., 65% R
Column of H "is a representation temperature 20 ° C., the oxygen permeability under conditions of RH 65% humidity in units of" ^{cc · 20μm / m 2 · 24hr} · atm ". "(60 ° C, 100% RH) /
(20 ° C, 65% RH) ”and“ (90 ° C, 100% RH)
H) / (20 ° C., 65% RH) ”, respectively.
° C, the amount of oxygen permeation under the condition of 100% RH and the temperature of 90 ° C, the amount of oxygen permeation under the condition of 100% RH,
It is a relative value based on the amount of oxygen permeated under the conditions of a temperature of 20 ° C. and a humidity of 65% RH.

Example 7 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight:
35000; weight-average molecular weight: 200000) 15.6
After dissolving the sol in 200 parts by weight of methanol, 2.28 parts by weight of tetramethoxysilane, 0.35 parts by weight of tetraisopropoxytitanium and 1.0 part by weight of 1N hydrochloric acid were added under a nitrogen atmosphere, and the sol was added. It was prepared and reacted at 60 ° C. for 4 hours while stirring. The obtained sol is transferred to a flat-bottomed polytetrafluoroethylene (Dupont “Teflon”) container so as to have a height of 2 mm, and then the upper open part of the container is made of a polyvinylidene chloride film (Asahi Kasei Kogyo “Saran Wrap”). And reacted at 60 ° C. for another 4 hours. Thereafter, the coating film was removed, and the reaction was continued at 60 ° C. for another 4 hours. Next, when the residual ratio of acetyl groups in the organic polymer in the system reached 60 mol%, the reaction system was decompressed (pressure: 100 mmH).
g), and the reaction was carried out at 60 ° C. while controlling the amount of the carboxylic acid compound (acetic acid compound in this example) in the reaction system to satisfy the above formula (I). After 4 hours, the pressure was changed to 20 mmHg, and the reaction was continued at 40 ° C for 4 hours. Thus, a colorless and transparent film composed of the ethylene-vinyl alcohol copolymer / silica-titania composite was obtained. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. Table 2 shows the obtained results. Table 2 also shows the amount of the carboxylic acid compound present in the reaction system for each 10 mol% of the residual ratio of acyl groups at a stage of 45 mol% or less.

Example 8 Tetramethoxysilane 2.2
Instead of the combination of 8 parts by weight and 0.35 parts by weight of tetraisopropoxytitanium, 2.02 parts of tetramethoxysilane were used.
The reaction was carried out in the same manner as in Example 7 except that a combination of 0.71 parts by weight of tetraisopropoxytitanium and 0.71 parts by weight of tetraisopropoxytitanium was used.
A colorless and transparent film composed of the silica-titania composite was obtained. However, changes in the amount of carboxylic acid compounds are shown in Table 2.
Was as shown in FIG. About the obtained film, W
The m / Wc ratio was determined, the morphology was observed, the average pore diameter of the sintering residue was measured, the gas barrier properties were evaluated, and the flexibility was evaluated. The results are shown in Table 2.

Example 9 Tetramethoxysilane 2.2
Instead of the combination of 8 parts by weight and 0.35 parts by weight of tetraisopropoxytitanium, 1.77 of tetramethoxysilane was used.
The reaction was carried out in the same manner as in Example 7 except that a combination of 1.06 parts by weight of tetraisopropoxytitanium and 1.06 parts by weight of tetraisopropoxytitanium was used.
A colorless and transparent film composed of the silica-titania composite was obtained. However, changes in the amount of carboxylic acid compounds are shown in Table 2.
Was as shown in FIG. About the obtained film, W
The m / Wc ratio was determined, the morphology was observed, the average pore diameter of the sintering residue was measured, the gas barrier properties were evaluated, and the flexibility was evaluated. The results are shown in Table 2.

Example 10 Tetramethoxysilane 2.
Instead of the combination of 28 parts by weight and 0.35 parts by weight of tetraisopropoxytitanium, 3.2 parts by weight of tetraethoxysilane were used.
By conducting the reaction in the same manner as in Example 7 except that a combination of 9 parts by weight and 0.20 parts by weight of triisopropoxyaluminum was used, a colorless ethylene-vinyl alcohol copolymer / silica-alumina composite was obtained. A transparent film was obtained. However, the transition of the amount of the carboxylic acid-based compound was as shown in Table 2. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. The results are shown in Table 2.

Example 11 Tetramethoxysilane 2.
Instead of the combination of 28 parts by weight and 0.35 parts by weight of tetraisopropoxytitanium, 3.2 parts by weight of tetraethoxysilane were used.
9 parts by weight and 0.13 of tetraisopropoxy zirconium
A colorless and transparent film composed of an ethylene-vinyl alcohol copolymer / silica-zirconia composite was obtained by carrying out the reaction in the same manner as in Example 7 except that the combination with parts by weight was used. However, the transition of the amount of the carboxylic acid-based compound was as shown in Table 2. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. The results are shown in Table 2.

[0079]

[Table 2]

The term "silica / metal oxide" in Table 2 indicates the ratio of silica to the total metal oxide produced by the mole fraction of metal atoms (mol%). In addition, "abundance of carboxylic acid compound",
The “acyl group remaining rate”, “morphology” and “gas barrier property” are as described in Table 1 above.

<Example 12> A colorless and transparent film comprising an ethylene-vinyl alcohol copolymer / silica composite was obtained by conducting the reaction in the same manner as in Example 2 except that 0.5 parts by weight of distilled water was not added. I got Changes in the amount of carboxylic acid compounds during the reaction, determination of the Wm / Wc ratio, morphology observation, measurement of the average pore diameter of the sintering residue, evaluation of gas barrier properties, and evaluation of flexibility were performed on the obtained film. It is shown in Table 3.

<Example 13> The amount of 1N hydrochloric acid used was changed to 1.
Example 2 except for changing from 0 parts by weight to 0.1 parts by weight
By carrying out the reaction in the same manner as described above, a colorless and transparent film composed of an ethylene-vinyl alcohol copolymer / silica composite was obtained. Changes in the amount of the carboxylic acid compound during the reaction, and Wm performed on the obtained film
Table 3 shows the results of the determination of the / Wc ratio, the morphology observation, the measurement of the average pore diameter of the sintering residue, the evaluation of the gas barrier properties, and the evaluation of the flexibility.

<Example 14> Example 2 was repeated except that 0.6 parts by weight of acetic acid was used instead of 1.0 part by weight of 1N hydrochloric acid.
By carrying out the reaction in the same manner as described above, a colorless and transparent film composed of an ethylene-vinyl alcohol copolymer / silica composite was obtained. Changes in the amount of the carboxylic acid compound during the reaction, and Wm performed on the obtained film
Table 3 shows the results of the determination of the / Wc ratio, the morphology observation, the measurement of the average pore diameter of the sintering residue, the evaluation of the gas barrier properties, and the evaluation of the flexibility.

Example 15 The amount of 1N hydrochloric acid used was changed to 1.
Same as Example 2 except that the sol was changed from 0 parts by weight to 0.1 parts by weight, and 0.1 parts by weight of triethylamine was added to the sol and completely dissolved before the transfer to the polytetrafluoroethylene container. To obtain a colorless and transparent film composed of an ethylene-vinyl alcohol copolymer / silica composite. Changes in the amount of carboxylic acid compounds during the reaction, determination of the Wm / Wc ratio, morphology observation, measurement of the average pore diameter of the sintering residue, evaluation of gas barrier properties, and evaluation of flexibility were performed on the obtained film. It is shown in Table 3.

Comparative Example 2 Instead of 15.6 parts by weight of ethylene-vinyl acetate copolymer, an ethylene-vinyl alcohol copolymer (EVAL EP-F manufactured by Kuraray Co., Ltd.) was used.
101 "), except that 9.0 parts by weight of the ethylene-vinyl alcohol copolymer were used. / Silica composite was obtained. About the obtained film, Wm /
The Wc ratio was determined, the morphology was observed, the average pore size of the sintering residue was measured, the gas barrier property was evaluated, and the flexibility was evaluated. Table 3 shows the obtained results.

[0086]

[Table 3]

The "amount of carboxylic acid compound", "acyl group residual ratio", "morphology" and "gas barrier property" in Table 3 are as described in Table 1 above.

Example 16 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 35,000; weight average molecular weight: 200000) 1
14.9 weight parts saponified ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; saponification degree: 10 mol%; number average molecular weight: 33500; weight average molecular weight: 190000) instead of 5.6 parts by weight The reaction was carried out in the same manner as in Example 2 except that
A colorless and transparent film composed of a vinyl alcohol copolymer / silica composite was obtained. Changes in the amount of carboxylic acid compounds during the reaction, determination of the Wm / Wc ratio, morphology observation, measurement of the average pore diameter of the sintering residue, evaluation of gas barrier properties, and evaluation of flexibility were performed on the obtained film. It is shown in Table 4.

Example 17 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 35000; weight average molecular weight: 200000) 1
Instead of 5.6 parts by weight, an ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight:
35000; weight average molecular weight: 200000) 14.0
Weight part and ethylene-vinyl alcohol copolymer (ethylene unit content: 32 mol%; saponification degree: 99.95 mol%; number average molecular weight: 20,000; weight average molecular weight: 11
6000) except that a mixture with 0.9 parts by weight (apparent degree of saponification of the mixture: 10 mol%) was used. A colorless transparent film consisting of a body was obtained. Changes in the amount of the carboxylic acid compound present during the reaction, and Wm / W performed on the obtained film
Table 4 shows the results of the determination of the c ratio, the morphology observation, the measurement of the average pore size of the sintering residue, the evaluation of gas barrier properties, and the evaluation of flexibility.

Example 18 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 35000; weight average molecular weight: 200000) 1
Instead of 5.6 parts by weight, an ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight:
20,000; weight average molecular weight: 80000) By reacting in the same manner as in Example 2 except that a mixture of 12.5 parts by weight and 3.5 parts by weight of polyvinyl acetate was used, an ethylene-vinyl alcohol copolymer was obtained. A colorless and transparent film composed of a mixture with polyvinyl alcohol / silica composite was obtained. Changes in the amount of the carboxylic acid compound present during the reaction, and Wm / W performed on the obtained film
Table 4 shows the results of the determination of the c ratio, the morphology observation, the measurement of the average pore size of the sintering residue, the evaluation of gas barrier properties, and the evaluation of flexibility.

Example 19 Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 35000; weight average molecular weight: 200000) 1
Instead of 5.6 parts by weight, a modified ethylene-vinyl acetate copolymer modified with 0.1 mol% (based on acetoxy group) silyl group (ethylene unit content: 32 mol%; number average molecular weight:
30,000; weight average molecular weight: 180000) 15.6
A colorless and transparent film comprising a modified ethylene-vinyl alcohol copolymer / silica composite was obtained by carrying out the reaction in the same manner as in Example 2 except that the parts by weight were used. Changes in the amount of the carboxylic acid compound present during the reaction, and determination of the Wm / Wc ratio performed on the obtained film,
Table 4 shows the results of the morphology observation, the measurement of the average pore size of the sintering residue, the evaluation of the gas barrier property, and the evaluation of the flexibility.

Example 20 Tetramethoxysilane 2.
Instead of 5 parts by weight, a mixture consisting of 2.2 parts by weight of tetramethoxysilane, 0.10 parts by weight of hydrophilic treated smectite having an aspect ratio of 1000 and 0.1 part by weight of γ-glycidoxypropyltrimethoxysilane was used. A colorless and transparent film comprising an ethylene-vinyl alcohol copolymer / silica composite was obtained by carrying out the reaction in the same manner as in Example 2 except for the above points. Changes in the amount of carboxylic acid compounds during the reaction, determination of the Wm / Wc ratio, morphology observation, measurement of the average pore diameter of the sintering residue, evaluation of gas barrier properties, and evaluation of flexibility were performed on the obtained film. It is shown in Table 4.

Comparative Example 3 In preparing a sol from ethylene-vinyl alcohol copolymer, tetramethoxysilane, methanol, distilled water and 1N hydrochloric acid, γ-glycidoxypropyltrimethoxysilane (coupling agent) was used. By conducting the reaction in the same manner as in Comparative Example 2 except that 0.1 part by weight was added, a film comprising an ethylene-vinyl alcohol copolymer / silica composite was obtained. About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. Table 4 shows the obtained results.

Comparative Example 4 0.1 mol% (based on hydroxyl group)
Modified ethylene-vinyl alcohol copolymer modified with a silyl group (ethylene unit content: 32 mol%; saponification degree: 9)
(9 mol%; number average molecular weight: 30000; weight average molecular weight: 180,000) is dissolved in a mixture of 120 parts by weight of distilled water and 180 parts by weight of propanol, and then 2.5 parts by weight of tetramethoxysilane is dissolved. And 1N-
A sol was prepared by adding 1.0 part by weight of hydrochloric acid, and the mixture was reacted at 60 ° C. for 4 hours while stirring. The obtained sol is transferred to a flat-bottomed polytetrafluoroethylene (Dupont “Teflon”) container so as to have a height of 3 mm, and then the upper open part of the container is a polyvinylidene chloride film (Asahi Kasei Kogyo “Saran Wrap”). And reacted at 60 ° C. for another 4 hours. Thereafter, a hole was formed in the coating film with a needle so that the porosity was 2% based on the area of the coating film, and the reaction was continued at 60 ° C. for further 6 hours. Next, the inside of the reaction system was transferred to a reduced pressure system (pressure: 100 mmHg), and low boiling substances in the reaction system were removed at 60 ° C. for 4 hours. Thus, a colorless and transparent film composed of the modified ethylene-vinyl alcohol copolymer / silica composite was obtained.
About the obtained film, Wm / Wc ratio determination, morphology observation, measurement of the average pore diameter of the sintering residue, gas barrier property evaluation, and flexibility evaluation were performed. Table 4 shows the obtained results.

[0095]

[Table 4]

The term “ethylene-vinyl alcohol copolymer or precursor” in Table 4 refers to the ethylene-vinyl alcohol copolymer used for preparing the composition and / or
Or, it means an ethylene-vinyl alcohol copolymer-forming precursor, and “EVAc” and “EVOH” represent “ethylene-vinyl acetate copolymer” and “ethylene-vinyl alcohol copolymer”, respectively. "PVAc" in the item "Other additives" is "Polyvinyl acetate"
Represents In addition, "abundance of carboxylic acid compound",
The “acyl group remaining rate”, “morphology” and “gas barrier property” are as described in Table 1 above.

<Example 21> The porosity of the coated film was set to 1
% To 10%, and the subsequent reaction operation was performed at 60 ° C.
For 4 hours, and when the residual ratio of acyl groups of the organic polymer in the reaction system reaches 55 mol%, the reaction system is transferred to a reduced pressure system (pressure: 150 mmHg), and the carboxylic acid compound in the reaction system is reacted. (Acetic acid compound in this example) The reaction is carried out at 60 ° C. while controlling the amount to satisfy the above formula (I). After 4 hours, the reaction is continued for 4 hours under the conditions of pressure of 30 mmHg and 40 ° C. A colorless and transparent film composed of an ethylene-vinyl alcohol copolymer / silica composite was obtained by carrying out the reaction in the same manner as in Example 2 except for the above changes. Changes in the amount of the carboxylic acid-based compound during the reaction, and W performed on the obtained film
Table 5 shows the results of the determination of the m / Wc ratio, the morphology observation, the measurement of the average pore size of the sintering residue, the evaluation of the gas barrier property, and the evaluation of the flexibility.

<Examples 22 and 23> Except that the amount of the carboxylic acid compound in the reaction system was changed as shown in Table 5 by changing the reaction pressure and the reaction temperature,
By carrying out the reaction in the same manner as in Example 21, a colorless and transparent film comprising the ethylene-vinyl alcohol copolymer / silica composite was obtained. Table 5 shows the results of the Wm / Wc ratio determination, morphology observation, measurement of the average pore size of the sintering residue, gas barrier property evaluation, and flexibility evaluation performed on the obtained film.

[0099]

[Table 5]

The "amount of carboxylic acid compound", "residual acyl group", "morphology" and "gas barrier property" in Table 5 are as described in Table 1 above.

According to Tables 1 to 5, the ethylene-vinyl alcohol copolymer compositions according to the present invention obtained in Examples 1 to 23 only have excellent gas barrier properties under ordinary temperature and humidity conditions. In addition, it can be seen that the gas barrier property is hardly reduced even under high temperature and high humidity conditions. Among them, the Wm / Wc ratio is 0.001.
Examples 1-4 and Examples 6-2 within the range of ~ 1.0
It can be seen that the ethylene-vinyl alcohol copolymer composition obtained in 3 is further excellent in flexibility.

On the other hand, the ethylene-vinyl alcohol copolymer composition of Comparative Example 1, which is different from the present invention in the Wm / Wc ratio, the morphology and the average pore diameter of the sinter residue, the morphology and the sinter residue It can be seen that in the ethylene-vinyl alcohol copolymer compositions of Comparative Examples 2 to 4, which differ from the present invention in the average pore diameter of the present invention, the gas barrier properties under the conditions of high temperature and high humidity are significantly reduced.

<Example 24> Ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 60000; weight average molecular weight: 400,000) 1
After dissolving 6.5 parts by weight in 100 parts by weight of methanol, 1.26 parts by weight of tetramethoxysilane and 0.4 of distilled water are dissolved.
A sol was prepared by adding 1 part by weight and 1.2 parts by weight of 1N-hydrochloric acid, and reacted at 60 ° C. for 6 hours while stirring.
The obtained sol was applied on a 100 μm-thick polyethylene terephthalate film and reacted at 60 ° C. for 4 hours. Thereafter, the reaction system was transferred to a reduced pressure system, and the reaction was carried out at 150 ° C. while controlling the amount of the carboxylic acid compound (acetic acid compound in this example) in the reaction system to satisfy the above formula (I). . Thus, a colorless and transparent laminated film composed of the layer of the ethylene-vinyl alcohol copolymer / silica composite and the layer of polyethylene terephthalate was obtained.
The laminated film had good morphology without warpage. For the layer of the ethylene-vinyl alcohol copolymer / silica composite of the obtained laminated film, the Wm / Wc ratio was determined, the morphology was observed, and the average pore size of the sintering residue was measured. And flexibility evaluation. Table 6 shows the obtained results. Table 6 also shows the amount of the carboxylic acid-based compound present in the reaction system for each residual ratio of 10 mol% at a stage where the residual ratio of acyl groups is 45 mol% or less.

<Examples 25 to 28> In Example 24, 16.5 parts by weight of an ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%; number average molecular weight: 60000; weight average molecular weight: 400,000) Combination with 1.26 parts by weight of tetramethoxysilane was combined with an ethylene-vinyl acetate copolymer (ethylene unit content: 32 mol%;
Number average molecular weight: 35000; Weight average molecular weight: 2000
00) Combination of 15.6 parts by weight and 2.5 parts by weight of tetramethoxysilane (Example 25), ethylene-vinyl acetate copolymer (ethylene unit content: 44 mol%; number average molecular weight: 20,000; weight) (Average molecular weight: 50,000) 1
A combination of 1.4 parts by weight and 7.6 parts by weight of tetramethoxysilane (Example 26), an ethylene-vinyl acetate copolymer (ethylene unit content: 44 mol%; number average molecular weight: 4)
2000; weight average molecular weight: 150,000) in combination with 8.2 parts by weight of tetramethoxysilane (Example 27), or ethylene-vinyl acetate copolymer (ethylene unit content: 47 mol%; Number average molecular weight: 3
6000; weight average molecular weight: 130,000) The reaction was carried out in the same manner except that the combination was changed to 3.2 parts by weight of tetramethoxysilane (Example 28) to obtain a copolymer of ethylene-vinyl alcohol. A colorless and transparent film composed of the combined / silica composite was obtained. However,
Table 6 shows changes in the amount of carboxylic acid compounds present during the reaction.
Was as shown in FIG. About the obtained film, W
Table 6 also shows the results of the determination of the m / Wc ratio, the morphology observation, the measurement of the average pore size of the sintering residue, the evaluation of the gas barrier property, and the evaluation of the flexibility.

[0105]

[Table 6]

The "amount of carboxylic acid compound", "acyl group residual ratio", "morphology" and "gas barrier property" in Table 6 are as described in Table 1 above.

According to Table 6, the laminated films obtained in Examples 24 to 28 according to the present invention not only have excellent gas barrier properties under normal temperature and humidity conditions, but also have high temperature and high humidity conditions. It can be seen that the lowering of the gas barrier property is small even below. Among them, Wm
Example 24 in which the / Wc ratio was in the range of 0.001 to 1.0
It can be seen that the laminated films obtained in Nos. To 27 were particularly excellent in flexibility.

[0108]

According to the present invention, there is provided an ethylene-vinyl alcohol copolymer composition containing a metal oxide,
Provided is a composition having excellent barrier properties against gases such as oxygen, water vapor, carbon dioxide gas, and nitrogen, and capable of maintaining the excellent barrier properties to a high degree even under high temperature and high humidity conditions.
Further, according to the present invention, there is provided a laminated film in which the features of the ethylene-vinyl alcohol copolymer composition are effectively exhibited. Therefore, the ethylene-vinyl alcohol copolymer composition and the laminated film of the present invention are particularly useful as a film-like packaging material such as a food packaging material that requires good gas barrier properties that are not affected by environmental conditions such as humidity. .

Claims (3)

[Claims] 1. A composition comprising a metal oxide and an ethylene-vinyl alcohol copolymer, wherein (1) the content of silicon atoms based on all metal atoms in the metal oxide is 20 mol% or more. (2) the value Wm / Wc of the ratio of the weight Wm of the metal atom derived from the metal oxide contained in the composition to the weight Wc of the carbon atom contained in the composition is 0.5.
(3) (a) the phase comprising the ethylene-vinyl alcohol copolymer and the phase comprising the metal oxide each form a bicontinuous structure, or B) The phase comprising the ethylene-vinyl alcohol copolymer and the phase comprising the metal oxide form a sea-island structure, and the sea component comprises the ethylene-vinyl alcohol copolymer, and the island component comprises the metal oxide. It has a form of a co-continuous structure in which a phase made of an ethylene-vinyl alcohol copolymer is embedded in particles having an average particle diameter of 100 nm or less, and (4) a sintering residue at 500 ° C. The average pore diameter determined by the BET method is 4.0 n
m or less, wherein the ethylene-vinyl alcohol copolymer composition is not more than m. 2. The ethylene-vinyl alcohol copolymer composition according to claim 1, wherein the ethylene unit content of the ethylene-vinyl alcohol copolymer is in the range of 20 to 70 mol% based on all constitutional units. 3. A laminated film comprising at least one layer comprising the ethylene-vinyl alcohol copolymer composition according to claim 1.