JP2003103713A - Gas barrier film and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gas barrier film having excellent characteristics. SOLUTION: The gas barrier film is obtained by coating the surface of a film substrate with a gas barrier coating agent containing an organic compound (I) having a nitrogen atom to which active hydrogen is bonded in its molecule, an organic compound (II) having a functional group, which can be reacted with active hydrogen to form a chemical bond along with the nitrogen atom, in its molecule, an organosilicon compound represented by the formula : R<1> m Si(OR<2> )n and/or a hydrolyzed condensate thereof (III) and a solvent (IV) and curing the coated film substrate. The thicknesses of the gas barrier layer measured at five points at every 100 m in the longitudinal direction of the gas barrier film are within ±20% of the average value of the thicknesses of the gas barrier layer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas barrier film having extremely low permeability to gases such as oxygen, carbon dioxide and water vapor, and more particularly to a gas barrier film having particularly excellent flex resistance.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for gas barrier films having extremely low permeability to gases such as oxygen, nitrogen, carbon dioxide and water vapor in the fields of packaging, medicine and the like.

As a method for producing a gas barrier film, a film itself is formed from a material having a gas barrier property such as an ethylene-vinyl alcohol copolymer, a vinylidene chloride copolymer, and an aromatic nylon. Methods such as laminating or coating a material having the above on a film base material, laminating an aluminum foil on the film base material, and vapor depositing a metal oxide on the surface of the film base material have been adopted.

However, none of these gas barrier materials can be said to satisfy all of moisture resistance, environmental resistance, transparency and flexibility. Specifically, the ethylene-vinyl alcohol copolymer and the aromatic nylon have a significantly reduced gas barrier property as the humidity of the atmosphere increases. Since the vinylidene chloride-based copolymer contains chlorine atoms, it may cause pollution. When the aluminum foil is laminated on the film substrate, the gas barrier film becomes opaque and the contents of the package cannot be confirmed. Further, when a metal oxide is vapor-deposited on the surface of the gas barrier film, cracks are likely to occur in the vapor deposition layer, and the gas barrier property is deteriorated.

In order to solve these problems, the present inventors have already proposed a gas barrier coating agent and a gas barrier film having a film containing a polysiloxane polymer formed on the surface using the same. (JP-A-8-
295848, etc.). Such a gas barrier film retains high gas barrier properties and is excellent in moisture resistance, environmental properties, transparency and flexibility, and can be said to have extremely high utility when applied to various applications.

[0006]

Although it is considered that the gas barrier film described above has no problem in practical use, it is still better to produce a more excellent gas barrier film. Further, there is a possibility that an industry will be required in the future that requires a stricter level than the level currently required for the gas barrier film.

In view of the above matters, it is an object of the present invention to provide a gas barrier film having extremely excellent characteristics and a method for producing the same.

[0008]

The present invention is excellent in a gas barrier film formed by coating the surface of a film substrate with a coating agent for gas barrier so that the thickness of the gas barrier layer satisfies predetermined requirements. It was completed by paying attention to the point that it can provide bending resistance. The specific configuration of the present invention is as follows.

An organic compound (I) having a nitrogen atom bound to active hydrogen in the molecule and an organic compound (I) having a functional group capable of reacting with the active hydrogen to form a chemical bond with the nitrogen atom (II ) And the following formula (1):

[0010]

[Chemical 3]

(In the formula, R ¹ is a hydrogen atom or 1 carbon atom which may have a functional group which does not react with the active hydrogen.
To an alkyl group of R 4, R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is an integer of 0 or more, n is an integer of 1 or more, and m + n = 4, when m or n is 2 or more, R ¹ or R ² may be different) and / or a hydrolyzed condensate (III) thereof, and a solvent (IV) A gas barrier film obtained by coating and curing a gas barrier coating agent on the surface of a film substrate, wherein the gas barrier layer thickness measured at 5 points every 100 m in the longitudinal direction of the gas barrier film is the gas barrier layer thickness. A gas barrier film having an average value within ± 20%.

The average value of the gas barrier layer thickness is 0.3.
It is preferably about 2.0 μm.

Further, the present invention provides an organic compound (I) having a nitrogen atom to which active hydrogen is bonded in the molecule, and a functional group capable of reacting with the active hydrogen to form a chemical bond with the nitrogen atom in the molecule. An organic compound (II) having the following formula (1):

[0014]

[Chemical 4]

(In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a functional group that does not react with the active hydrogen, and R ² is a hydrogen atom or the number of carbon atoms. An alkyl group of 1 to 4, m is an integer of 0 or more, n is an integer of 1 or more, m + n = 4, m
Alternatively, when n is 2 or more, R ¹ or R ² may be different), an organic silicon compound represented by the formula (1) and / or a hydrolyzed condensate thereof (III), and a solvent (IV),
It is a method of producing a gas barrier film by coating and curing a gas barrier coating agent having a viscosity of 1 to 20 cps (20 ° C.) on the surface of a film substrate.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The gas barrier film of the present invention comprises an organic compound (I) having a nitrogen atom bound to active hydrogen in its molecule, and reacts with the active hydrogen to form a chemical bond with the nitrogen atom. An organic compound (II) having a functional group in the molecule and the following formula (1):

[0017]

[Chemical 5]

(In the formula, R ¹ is a hydrogen atom or 1 carbon atom which may have a functional group which does not react with the active hydrogen.
To an alkyl group of R 4, R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, m is an integer of 0 or more, n is an integer of 1 or more, and m + n = 4, when m or n is 2 or more, R ¹ or R ² may be different) and / or a hydrolyzed condensate (III) thereof, and a solvent (IV) A gas barrier film obtained by coating and curing a gas barrier coating agent on the surface of a film substrate, wherein the gas barrier layer thickness measured at 5 points every 100 m in the longitudinal direction of the gas barrier film is the gas barrier layer thickness. A gas barrier film having an average value within ± 20%.

The gas barrier film of the present invention having the above structure has excellent gas barrier properties, moisture resistance, transparency, flexibility, mechanical strength and hardness, and is also excellent in bending resistance. Become. Moreover, when the viscosity of the coating agent for gas barrier to be used is adjusted, the gas barrier film having the above constitution can be produced efficiently and relatively easily.

First, constituent components of the gas barrier coating agent used in the process of producing the gas barrier film of the present invention will be described.

The organic compound (I), which is one of the main constituents of the coating agent for gas barrier, is not particularly limited as long as it has a nitrogen atom to which active hydrogen is bonded in its molecule. In the present application, active hydrogen refers to a hydrogen atom which is highly reactive and reacts with various reagents, and specifically, -NH- (wherein, N is not bonded to any other hydrogen atom) or -NH. It exists as ₂ in the molecule. When the organic compound (I) is contained in the gas barrier coating agent, it is particularly effective in imparting flexibility to the gas barrier layer.

The molecular weight of the organic compound (I) is not particularly limited, but a polymer compound is preferable in view of the film-forming property and flexibility of the gas barrier layer to be formed. When a polymer compound is used as the organic compound (I), if the number average molecular weight is too small, the flexibility of the gas barrier layer formed on the film substrate may be poor, or the gas barrier layer formed on the film substrate or another gas barrier layer may be poor. There is a possibility that the film-forming property when coating and laminating may be inferior. Therefore, the number average molecular weight of the organic compound (I) is preferably 250 or more, more preferably 300 or more. On the other hand, if the number average molecular weight is too large, the formed gas barrier layer may be inferior in transparency, and the gas barrier layer may be inferior in flexibility. Therefore, the number average molecular weight of the organic compound (I) is preferably 200,000 or less, more preferably 100,000 or less, and 10
It is particularly preferable that it is 000 or less. However, those having a complicated structure that cannot be measured by the number average molecular weight can be used as the organic compound (I) in the present invention, and these compounds are not excluded from the present invention.

Specific examples of the organic compound (I) include low molecular weight compounds such as ethanolamine and high molecular weight compounds such as polyalkyleneimine and polyallylamine.

As the polyalkyleneimine, polymethyleneimine, polyethyleneimine, polypropyleneimine, polyisopropyleneimine, polybutyleneimine,
Examples thereof include polyisobutylene imine. The polyalkyleneimine can be prepared by using various known synthesis methods, or a commercially available product may be used. For example, Epomin series manufactured by Nippon Shokubai Co., Ltd .; Epomin SP-00
3, Epomin SP-006, Epomin SP-012, Epomin SP-018, Epomin SP-103, Epomin SP-110, Epomin SP-200, Epomin SP-
300, Epomin SP-1000, Epomin SP-10
Polyethyleneimine such as 20 (both are trade names) can be used.

As the polyallylamine, those synthesized by various known methods can be used, and PAA-L and PAA-H (both are trade names) manufactured by Nitto Boseki Co., Ltd. can be used.

These may be used alone or in combination of two or more. Among the above-listed organic compounds (I), polyalkyleneimine is preferable in consideration of transparency, heat resistance, flexibility and adhesion of the gas barrier layer. Polyethyleneimine is particularly preferable.

The organic compound (II), which is one of the main constituents of the coating agent for gas barrier, is the organic compound (I).
Is not particularly limited as long as it has a functional group in the molecule capable of reacting with active hydrogen bonded to the nitrogen atom contained in to form a chemical bond with this nitrogen atom. Such a functional group is not particularly limited, but an epoxy group, a carboxyl group, an isocyanate group, a thioisocyanate group, an oxazolinyl group, a (meth) acryl group, an aldehyde group, a ketone group, an alkyl halide group, etc. Can be mentioned. Considering the easiness of reaction with active hydrogen bonded to the nitrogen atom and the hot water resistance, an epoxy group is preferable. When the organic compound (II) is contained in the gas barrier coating agent, it is particularly effective in improving the film-forming property.

The reaction of a nitrogen atom having active hydrogen bonded with an epoxy group is generally represented by the following formulas (2) and (3):

[0029]

[Chemical 6]

(In the formula, R and R'represent an alkyl group which may have a functional group).

The organic compound (II) is not particularly limited, but specific examples of the compound containing an epoxy group as a functional group capable of forming a chemical bond with a nitrogen atom include 2
-Ethylhexyl glycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, tetraethylene glycol diglycidyl ether, nonaethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, dipropylene glycol diglycidyl ether, Aliphatic mono- and diglycidyl ethers such as tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, trimethylolpropane diglycidyl ether; glycerol triglycidyl Ether, diglycerol triglycidyl ether, Li glycidyl tris (2-hydroxyethyl) isocyanurate, trimethylolpropane triglycidyl ether, polyglycidyl ethers such as pentaerythritol tetraglycidyl ether;
Aliphatic and aromatic mono- and diglycidyl esters such as adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, phenylglycidyl ether; bisphenol A diglycidyl ether, resorcinol diglycidyl ether, hydroquinone diglycidyl ether, bisphenol S Diglycidyl ether, bisphenol F diglycidyl ether, and compounds represented by the following formula:

[0032]

[Chemical 7]

Glycidyl having an aromatic ring or its hydrogenated ring (including a nucleus-substituted derivative) such as; oligomers having a glycidyl group as a functional group (for example, in the case of bisphenol A diglycidyl ether oligomer, it can be represented by the following formula );

[0034]

[Chemical 8]

And the like.

Other specific examples of the compound having a functional group capable of forming a chemical bond with a nitrogen atom include hexamethylene diisocyanate, tolylene diisocyanate, 1,4-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate and triphenylmethane. Isocyanates such as triisocyanate, tolidine diisocyanate, xylylene diisocyanate, and dicyclohexylmethane diisocyanate; dicarboxylic acids such as tartaric acid and adipic acid; carboxyl group-containing polymers such as polyacrylic acid; oxazolinyl group-containing polymers.

These may be used alone or in combination of two or more. Among the organic compounds (II) exemplified above, compounds having an aromatic ring or a hydrogenated ring thereof (including a nucleus-substituted derivative) are preferable. This is because the effect of improving the water resistance of the gas barrier layer can be obtained by including a compound having an aromatic ring or a hydrogenated ring thereof.

The organic compound (II) has the following formula (4):

[0039]

[Chemical 9]

A functional group represented by (hereinafter referred to as "SiOR
³ groups ”) may be included in the molecule. In the formula,
R ³ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms is a linear alkyl group such as methyl group, ethyl group, propyl group or butyl group, branched alkyl group such as isopropyl group or isobutyl group,
It may be any cyclic (alicyclic) alkyl group such as a cyclopropyl group or a cyclobutyl group. Among these, a methyl group or an ethyl group is preferable from the viewpoint of easiness of reaction in forming a dense gas barrier layer.

[0041] If in the organic compound (II) has a ³ group SiOR proceeds hydrolysis condensation in ³ groups SiOR in before or after the reaction with the organic compound (I). In addition, cohydrolytic condensation proceeds with the hydrolyzable condensing group contained in the organic silicon compound described later. Due to the action of these polycondensation, it is possible to quickly form a dense gas barrier layer having excellent hard coat properties. It also has the effect of increasing the adhesion between the gas barrier layer and the film substrate. Furthermore, the moisture resistance of the gas barrier layer is improved, and after boiling sterilization,
A high gas barrier property can be maintained even when exposed to a high humidity of 90% Rh. When the organic compound (II) is a low molecular weight compound, it may be hydrolyzed and condensed before the reaction with the organic compound (II).

Specific examples of the organic compound (II) having a SiOR ³ group include β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane and β −
(3,4-Epoxycyclohexyl) ethyltriisopropoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldiethoxysilane, γ-glycidoxy Propyltrimethoxysilane, γ
-Glycidoxypropyltriethoxysilane, γ-glycidoxypropyltriisopropoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane and the like and Si (OR ³ ) A silane coupling agent having a group (R ³ is as defined above) (hereinafter sometimes simply abbreviated as an epoxy group-containing silane coupling agent); γ-isocyanopropyltrimethoxysilane, γ-isocyano Isocyanate groups such as propyltriethoxysilane, γ-isocyanopropylmethyldimethoxysilane, γ-isocyanopropylmethyldiethoxysilane and Si
(OR ³ ) group (R ³ is as defined above) -containing silane coupling agent (hereinafter, may be simply referred to as isocyanate group-containing silane coupling agent) and the like. These may be used alone or in combination of two or more.

Next, the organosilicon compound and / or its hydrolyzed condensate (III), which is one of the main constituents of the gas barrier coating agent, will be described. First, the organosilicon compound (III-1) will be described.
The organosilicon compound (III-1) has the following formula (1)

[0044]

[Chemical 10]

It is represented by

In the formula (1), R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. This alkyl group is
It may have a functional group which does not react with the active hydrogen contained in the organic compound (I). The functional group that does not react with the active hydrogen contained in the organic compound (I) is not particularly limited, and examples thereof include an amino group and a vinyl group. When it has a vinyl group, it has an effect of improving heat resistance and boiling resistance. Examples of the alkyl group having 1 to 4 carbon atoms include linear alkyl groups such as methyl group, ethyl group, propyl group and butyl group, branched alkyl groups such as isopropyl group and isobutyl group, and cyclic (alicyclic) groups such as cyclopropyl group and cyclobutyl group. ) It may be any of alkyl groups. Among these, a methyl group or an ethyl group is preferable from the viewpoint of easiness of reaction in forming a dense gas barrier layer. In addition, R ¹ may be the same or different when m is 2 or more.

In the formula (1), R ² is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. Examples of the alkyl group having 1 to 4 carbon atoms include linear alkyl groups such as methyl group, ethyl group, propyl group and butyl group, branched alkyl groups such as isopropyl group and isobutyl group, cyclopropyl group,
It may be any cyclic (alicyclic) alkyl group such as a cyclobutyl group. Among these, a methyl group or an ethyl group is preferable from the viewpoint of easiness of reaction in forming a dense gas barrier layer. R ² may be the same or different when n is 2 or more.

In the formula (1), m is an integer of 0 or more, n is an integer of 1 or more, and m + n = 4. Although not particularly limited, in consideration of heat resistance, boiling resistance and water resistance of the formed gas barrier layer, m = 0 and n = 4 are preferable.

Specific examples of the organosilicon compound (III-1) include tetramethoxysilane, tetraethoxysilane, tetraisopropoxysilane, tetrabutoxysilane, methyltrimethoxysilane, methyltriethoxysilane and methyltriisopropoxysilane. Methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, ethyltriisopropoxysilane, ethyltributoxysilane, dimethyldimethoxysilane,
Dimethyldiethoxysilane, dimethyldiisopropoxysilane, dimethyldibutoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, diethyldiisopropoxysilane, diethyldibutoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxy Silane, vinyltributoxysilane, γ-mercaptopropyltrimethoxysilane, γ-
Alkoxysilanes such as mercaptopropyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane and complex compounds thereof, methyltriacetoxysilane, trimethylsilanol, and polymers containing these compounds Organosilicon compounds may be mentioned. Among these, tetramethoxysilane and tetraethoxysilane are preferable in consideration of boiling resistance, moisture resistance and water resistance of the gas barrier layer. In addition, these may be used individually by 1 type, or may be used in combination of 2 or more type.

Next, the hydrolysis-condensation product (III-2) of the organosilicon compound will be described. The hydrolysis-condensation product (III-2) of the organosilicon compound refers to the hydrolysis-condensation product of the organosilicon compound (III-1) represented by the above formula (1). Instead of the organosilicon compound (III-1) or in addition to the organosilicon compound (III-1), the hydrolysis-condensation product of the organosilicon compound may be contained in the organic compound when the gas barrier layer is formed. This is because in order to prevent undesired drying of the compound (II) and the organosilicon compound (III-1), it is preferable to hydrolyze and condense them in advance. That is, the coating agent for gas barrier may contain the organosilicon compound (III-1) or may contain the hydrolyzed condensate (III-2) of the organosilicon compound (III-1). Good. Of course, both may be included. These hydrolysis-condensation reactions also proceed with water present in the air, but the reaction efficiency may be improved by using a known catalyst such as acid or base. Also, considering workability,
The hydrolysis reaction is preferably carried out in the solvent (IV).

When the above organosilicon compound (III-1) and / or its hydrolyzed condensate (III-2) is contained in the gas barrier coating agent, it has the effect of improving the moisture resistance of the gas barrier layer and the atmosphere. It is possible to maintain a sufficient gas barrier property even when the humidity of the gas increases. In addition, water resistance can be imparted, adhesion to the film substrate,
Hard coat property and heat resistance can be improved. Also,
When subjected to a harsh storage environment (for example, in a high humidity condition of 20 ° C. 90% Rh) after being subjected to boiling sterilization treatment, which is inevitable when used as a packaging material for foods and beverages. However, the excellent gas barrier property can be maintained. The organosilicon compound (III-1) and its hydrolyzed condensate (III-2) have no functional group capable of reacting with the active hydrogen bonded to the nitrogen atom of the organic compound (I). , And is clearly different from the organic compound (II).

The gas barrier coating agent used for producing the gas barrier film of the present invention is obtained by incorporating the above-mentioned (I) to (III) in the solvent (IV). The solvent (IV) is an organic compound (I), an organic compound (II), an organosilicon compound and / or a hydrolyzed condensate of an organosilicon compound (III), and other components (optionally high polarity described later) added as necessary. It is not particularly limited as long as it can dissolve the molecular compound (V) and the like, and specifically, methanol, ethanol, 2-propanol, butanol, pentanol, ethylene glycol, diethylene glycol, triethylene glycol, Alcohols such as ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, triethylene glycol monomethyl ether; acetone,
Ketones such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; aromatic hydrocarbons such as triene, benzene and xylene; hydrocarbons such as hexane, heptane and octane; acetates such as methyl acetate, ethyl acetate, propyl acetate and butyl acetate Others, such as ethylphenol ether, propyl ether, tetrahydrofuran and water.
Of these, alcohols such as methanol and ethanol are preferable because they are excellent in stability during hydrolysis reaction and storage stability. From these, one kind or a combination of two or more kinds can be used as the solvent (IV). When selecting the solvent (IV), the organic compound (I), the organic compound (II), the organosilicon compound (III-1) to be used are selected. ), The hydrolysis-condensation product (III-2) of the organosilicon compound, and other components to be added as necessary. This is because the gas barrier properties may differ slightly depending on the compatibility between the components used and the solvent (IV).

Next, the compounding amount in the gas barrier coating agent will be described.

The amount of the organic compound (I) to be blended should be determined depending on the blending ratio of the organic compound (II), the organosilicon compound and / or its hydrolysis-condensation product (III), the presence or absence of the use of additives, etc. And cannot be unambiguously defined, but is usually 5 to 70% by mass, preferably 10 to 60% by mass with respect to the total blending amount of the constituent components (excluding the solvent (IV)) of the gas barrier coating agent. The content is in the range of mass%, more preferably 15-40 mass%. If the compounding amount of the organic compound (I) is less than 5% by mass, the flexibility and impact resistance of the gas barrier layer may be deteriorated. On the other hand, if it exceeds 70% by mass, the water resistance and moisture resistance of the gas barrier layer and the adhesion to the film substrate may be poor.

The amount of the organic compound (II) to be blended should be determined depending on the blending ratio of the organic compound (I), the organosilicon compound and / or its hydrolyzed condensate (III), whether or not additives are used. And cannot be unambiguously defined, but is usually 5 to 50% by mass, preferably 7 to 35% by mass with respect to the total compounding amount of the constituent components (excluding the solvent (IV)) of the gas barrier coating agent. mass%,
It is more preferably in the range of 10 to 20% by mass. If the compounding amount of the organic compound (II) is less than 5% by mass, the gas barrier layer may be inferior in water resistance, moisture resistance and adhesion to the film substrate. On the other hand, if it exceeds 50 mass%, the gas barrier layer may have poor gas barrier properties, flexibility and impact resistance.

The blending amount of the organosilicon compound and / or its hydrolyzed condensate (III) should be determined depending on the blending ratio of the organic compound (I) and the organic compound (II) and the presence / absence of additives. Although it cannot be unambiguously specified, it is usually 10 to 80% by mass, preferably 20 to 70% by mass based on the total amount of the constituent components (excluding the solvent (IV)) of the gas barrier coating agent. The amount is in the range of 30% by mass, and more preferably 30 to 60% by mass. Organosilicon compound and / or its hydrolysis-condensation product (II
When the compounding amount of I) is less than 10% by mass, the gas barrier layer may be inferior in water resistance and moisture resistance. On the other hand, if it exceeds 80% by mass, the gas barrier layer may be inferior in flexibility. The "blending amount of the organosilicon compound and / or its hydrolysis-condensation product (III)" means the total blending amount of both, and only one of them is contained in the gas barrier coating agent. In this case, it means one of the blending amounts.

The compounding amount of the solvent (IV) is not particularly limited, but a coating agent for gas barrier (here, the solvent (I
(Including V)) is generally 20 to 97% by mass, preferably 50 to 95% by mass, more preferably 70 to 95% by mass, particularly preferably 75 to 100% by mass based on 100% by mass.
It is in the range of 90% by mass. When the compounded amount of the solvent (IV) is less than 20% by mass, the reaction stability of the coating agent for gas barrier may be inferior, and the viscosity of the coating agent for gas barrier may increase during coating, resulting in uniform coating. May not be possible. On the other hand, if it exceeds 97% by mass, the productivity when forming the gas barrier layer may be poor, and the active ingredient may be too low in concentration, so that the required thickness of the gas barrier layer may not be secured.

A polar polymer compound (V) having no nitrogen atom bonded to active hydrogen in the molecule may be further added to the gas barrier coating agent. The polar polymer compound (V) refers to a polymer compound having a polar functional group.
Examples of the polar functional group contained in the polar polymer compound (V) include a hydroxyl group, an amino group, an amide group and a carboxyl group. In addition to the composition obtained by reacting the above (I) to (III), a free polar polymer compound (V) that has not reacted with other compounds is included in the gas barrier coating agent to obtain a gas barrier coating. It is possible to impart excellent wettability to the coating composition. For this reason,
It is possible to improve the film-forming property when the film base material is coated with the gas barrier coating agent, and to form a gas barrier layer having good gas barrier properties. For example, this effect is remarkable when a material such as polycarbonate that is difficult to apply uniformly is used as the film substrate. Moreover, when a gas barrier layer is formed on the surface of a film substrate using a gas barrier coating agent containing a polar polymer compound (V), the gas barrier layer has improved flex resistance, that is, gas barrier property when bent. Can be suppressed. Although this mechanism is not clear, it is considered that the polysiloxane-based bond (Si-O-Si) has a high degree of crosslinking and has glass-like properties. That is, when the gas barrier layer is bent, the bonding portion may cause a decrease in the gas barrier property. However, in the present invention, the presence of the polar polymer compound (V) causes the gas barrier layer to bend. It is possible to suppress the deterioration of the gas barrier property to a minimum. Therefore, gas barriers can be used in fields where strict conditions regarding flex resistance are required (for example, films used in liquid crystal display parts of mobile phones, medical applications such as decompression blood collection tubes, but not limited to these). It can be said that there are enormous effects when applying a coating agent for use. These effects are largely obtained when the polar polymer compound (V) does not react with other compounds contained in the gas barrier coating agent, and therefore the polar polymer compound (V) is
When added to the solvent containing the reaction composition of (III), it is necessary that the polar polymer compound (V) and the organic compound (II) do not react with each other. Specifically, a method of adding the polar polymer compound (V) after the functional groups contained in the organic compound (II) have completely reacted, or a method of adding the polar polymer compound (V) that does not react with the organic compound (II) Is mentioned. Before adding the polar polymer compound (V), the organic compound (I), the organic compound (II) and the organic silicon compound and / or its hydrolyzed condensate (II
The conditions for reacting the solution containing I) should be determined by the compound to be used and the compounding amount, and cannot be defined unconditionally, but the unreacted product of the organic compound (I) is substantially present in the composition. It is preferable that the condition is such that it does not remain. This is because if the unreacted organic compound (I) remains, the film-forming property and stability of the obtained gas barrier layer may decrease. For example, at 30 to 80 ° C., 0.5 to
The reaction may be performed for about 5 hours.

The polar functional group contained in the polar polymer compound (V) is preferably a hydroxyl group and / or an amino group in consideration of the film-forming property when the gas barrier coating agent is coated on the film substrate. . That is, the polar polymer compound (V) is preferably a polymer compound having a hydroxyl group and / or an amino group. In addition,
The polar functional group contained in the polar polymer compound (V) is 1
The kind is not limited to a kind, and two or more kinds of polar functional groups may be contained in the polar polymer compound (V).

Polar polymer compound (V) containing a hydroxyl group
Examples thereof include polyvinyl alcohol, ethylene-vinyl alcohol copolymer, 2-hydroxyethyl (meth) acrylate-containing polymer and the like.

Examples of the polar polymer compound (V) containing a carboxyl group include homopolymers of (meth) acrylic acid and copolymers of (meth) acrylic acid and poly (meth) acrylate.

These may be used alone or in combination of 2
You may use it in combination of 2 or more types. In consideration of film forming property, the polar polymer compound (V) is preferably polyvinyl alcohol.

The molecular weight of the polar polymer compound (V) is not particularly limited, but if the number average molecular weight is too small, the flexibility of the gas barrier layer formed on the surface of the film substrate may be poor, or the film substrate may be poor. There is a possibility that the film-forming property at the time of coating and laminating on other gas barrier layers may be deteriorated. Therefore, the number average molecular weight of the polar polymer compound (V) is preferably 250 or more, more preferably 300 or more. On the other hand, if the number average molecular weight is too large, the formed gas barrier layer may be inferior in transparency,
Further, the flexibility of the gas barrier layer may be poor. Therefore, the number average molecular weight of the polar polymer compound (V) is 2000.
It is preferably 00 or less, more preferably 100,000 or less, and particularly preferably 10,000 or less. However, compounds having a complicated structure that cannot be measured by the number average molecular weight can also be used in the present invention as the polar polymer compound (V), and these compounds are not excluded from the present invention.

The compounding amount of the polar polymer compound (V), which is added as necessary, is such that the organic compound (I) and the organic compound (I
It should be determined according to I), the blending ratio of the organosilicon compound and / or its hydrolyzed condensate (III), the presence or absence of the use of other additives, etc., and cannot be uniquely defined. Is usually 0.1 to 10% by mass, preferably 0.2 to 5% by mass, and more preferably 0, based on the total amount of the constituents of the gas barrier coating agent (however, excluding the solvent (IV)). It is in the range of 0.5 to 2% by mass. The amount of the polar polymer compound (V) is 0.1
When it is less than mass%, the bending resistance, which is the effect of the present invention,
There is a possibility that the effect of improving wettability may not be sufficiently obtained. On the other hand, if it exceeds 10% by mass, the moisture resistance of the gas barrier layer may be deteriorated.

Further, the organic compound (I) and the organic compound (I
I), an organosilicon compound and / or its hydrolytic condensate (III), a solvent (IV), and a curing catalyst other than the polar polymer compound (V), a wettability improver, a plasticizer, an antifoaming agent, The amount of various inorganic or organic additives such as a thickener is within a range in which various properties of such additives can be sufficiently expressed, and which does not affect the expression effect such as gas barrier property, There is no particular limitation.

The organic compound (I) and the organic compound (I
I), an organosilicon compound and / or its hydrolytic condensate (III), and optionally a polar polymer compound (V) and a gas barrier coating agent containing other additives (excluding the solvent (IV)) The total compounding amount of () is always 100 mass% in any combination.

The gas barrier coating agent used for producing the gas barrier film of the present invention and containing the above-mentioned components has a viscosity at 20 ° C. of preferably 1 to 10 cps, and more preferably 2 to 8 cps. More preferable. When the viscosity is less than 1 cps, the gas barrier film of the present invention may not be uniform in thickness, which is a feature of the gas barrier film. On the other hand, when it exceeds 10 cps, productivity when forming the gas barrier layer may be deteriorated. The viscosity can be adjusted by selecting the types of the constituent components (I) to (V) of the gas barrier coating agent and other additives, and adjusting the concentration. For example, a method of suppressing the molecular weight of the compound used, a method of increasing the amount of the solvent (IV), a method of using a solvent (IV) having a low viscosity and the like can be exemplified. The viscosity of the coating agent for gas barrier can be measured by a viscometer, and for example, VM-100A manufactured by Yamaichi Denki Co., Ltd. can be used.
The relationship between the viscosity and the uniformity of the gas barrier layer will be described in more detail later.

The method for preparing the coating agent for gas barrier is not particularly limited, and for example, the following method can be used.

(1) A compounding component containing the organic compound (I), the organic compound (II), the organosilicon compound and / or its hydrolytic condensate (III), and the solvent (IV) (other optional components). May be included)),
(2) A method of reacting the organic compound (I) with the organic compound (II) in the presence of a solvent (IV) in advance to add an organosilicon compound and / or a hydrolytic condensate (III) thereof, ( 3) Organic compound (I) and solvent (I
V) in the presence of organic compound (I) or organic compound (I
I) and organosilicon compound (III-1) are (co) hydrolyzed and condensed, and a polar polymer compound (V) is added if necessary, (4) Organic compound in the presence of solvent (IV) (I) or organic compound (II) and organic silicon compound (II
I-1) is co-hydrolyzed and condensed, and then reacted with the organic compound (I), and the polar polymer compound (V) is added if necessary. However, the method is not limited thereto. It shouldn't be. The solvent (IV) is
It is desirable to replenish or add an appropriate substance in a timely manner depending on the preparation stage and method.

If necessary, a suitable amount of various inorganic or organic additives such as a curing catalyst, a wettability improver, a plasticizer, an antifoaming agent and a thickener may be added to the gas barrier coating agent. it can. That is, the gas barrier coating agent may further contain a curing catalyst or the like in addition to the essential components (I) to (III), and such an embodiment is also within the technical scope intended by the present invention. It is included.

A gas barrier film is produced by coating a film substrate with the above-described gas barrier coating agent and curing it. The type of film base material should be selected according to the application, and a plastic film having transparency is generally used. More specifically, transparent polyethylene terephthalate (PET), polybutylene terephthalate (PBT),
A film made of a polyester resin such as polyethylene naphthalate (PEN); a polyamide resin such as nylon 6, nylon 66, or nylon 46; a polyolefin resin such as polypropylene or polyethylene can be used. However, the present invention is not limited to this, and semitransparent plastic, opaque plastic, glass, ceramics, and metal can be used as the film substrate.

When a transparent plastic film is used as the film substrate, its surface is subjected to plasma treatment or corona discharge treatment in advance, or is exposed to ultraviolet rays having a wavelength of about 200 to 400 nm in an atmosphere containing oxygen. It is preferable to apply the coating agent for gas barrier after the irradiation. A known anchor coat layer of urethane resin or the like may be provided on the surface of the film substrate before applying the coating agent for gas barrier. By such pretreatment, a coated film having excellent adhesion to the base material is obtained.

In the present invention, in order to exhibit excellent flex resistance, the thickness of the gas barrier layer obtained by coating the film base material with the coating agent for gas barrier has a certain uniformity after drying. I need. Specifically, the thickness of the gas barrier layer measured at 5 points every 100 m in the longitudinal direction of the produced gas barrier film is required to be within ± 20% of the average value of the gas barrier layer thickness. For example, assume that the thickness of the gas barrier layer of the gas barrier film is measured at 5 points every 100 m in the longitudinal direction and the average value is 1.0 μm. In this case, the average value is within ± 20% of 1.0 μm, that is, 0.8
It is sufficient that all five gas barrier layer thicknesses fall within the range of up to 1.2 μm. The thickness of the gas barrier layer can be measured using a TEM, and the measurement point can be the side surface of the gas barrier film. 100 in the longitudinal direction
There are no particular restrictions on the positions of the five points when measuring every m, and at least one of the gas barrier film thicknesses is measured when five points are measured every 100 m from any part of the gas barrier film. If it is within ± 20% of the average value, it is included in the technical scope of the present invention. In addition, in the range where the gas barrier layer thickness of the gas barrier film is substantially stable, it is 5 in every 100 m in the longitudinal direction.
± 20 of the average value of gas barrier layer thickness when measuring points
%, And more preferably within ± 20% of the average value of the gas barrier layer thickness at any part of the gas barrier film in the longitudinal direction.

When the thickness of the gas barrier layer of the gas barrier film is controlled as described above, the bending resistance of the gas barrier layer can be improved. Although this mechanism is not clear, it is considered that the polysiloxane-based bond (Si-O-Si) has a high degree of crosslinking and has glass-like properties. That is, when the gas barrier film having a uniform thickness of the gas barrier layer is bent, it is considered that the stress generated by the bending is evenly generated in the gas barrier film. On the other hand, when the gas barrier film having a nonuniform thickness of the gas barrier layer is bent, the stress generated by the bending does not occur evenly with respect to the gas barrier film,
Strong stress is applied to some parts. It is considered that this causes a decrease in gas barrier properties. In the present invention,
By making the thickness of the gas barrier layer of the gas barrier film uniform, the deterioration of the gas barrier property when bent can be suppressed to a minimum. Therefore, gas barriers can be used in fields where strict conditions regarding flex resistance are required (for example, films used in liquid crystal display parts of mobile phones, medical applications such as decompression blood collection tubes, but not limited to these). When applying a coating agent for
It can be said that it has a great effect.

Means for controlling the thickness of the gas barrier layer so as to satisfy the requirements of the present invention include, for example, a method of controlling the viscosity, a method of cleaning the surface of the film base material, and a method of modifying the surface of the film base material. Examples thereof are not particularly limited. However, it can be said that the method of controlling the viscosity is preferable in consideration of workability, manufacturing cost, simplicity, and the like. As explained above, the viscosity of the coating agent for gas barrier is
This is because it can be easily adjusted by selecting the compounds (I) to (V), using additives, adjusting the mass ratio, and the like. The cleaning of the film base material and the surface modification of the film base material are effective when the coating agent for gas barrier cannot be applied uniformly due to stains attached to the film base material. Examples of the cleaning method include degreasing cleaning with an organic solvent such as alcohol, acetone, hexane, cleaning with an alkali or acid, a method of cleaning the surface by polishing with an abrasive, and a cleaning method such as ultrasonic cleaning. Examples of the surface modification method include ultraviolet irradiation treatment, ultraviolet ozone treatment, plasma treatment, corona discharge treatment, and heat treatment.

The method of coating the surface of the film substrate with the coating agent for gas barrier is not particularly limited, and conventionally known techniques can be appropriately used. For example, roll printing method, dip coating method, bar coating method, nozzle coating method, die coating method, spray coating method, spin coating method, curtain coating method, flow coating method, screen printing, gravure printing, curved surface printing, etc. Etc., or a combination thereof can be adopted. Among them, the die coating method is preferable in order to increase the stability of the gas barrier coating agent.

The thickness of the gas barrier layer cannot be uniquely defined because it depends on the intended use, but the average value of the thickness of the gas barrier layer measured at 5 points every 100 m in the longitudinal direction of the gas barrier film is 0.3 to. The thickness is preferably 2.0 μm, more preferably 0.4 to 1.5 μm, and particularly preferably 0.5 to 1.0 μm.
If the average thickness of the gas barrier layer is less than 0.3 μm, pinholes may occur. On the other hand, when the average value of the gas barrier layer thickness exceeds 2.0 μm, the bending resistance may be poor.

Curing and drying of the coating agent for gas barrier, which is carried out after coating, is carried out by heating or, if necessary, adding humidification. As a result, a dense gas barrier layer having excellent hard coat properties can be quickly formed. However, when heating is performed, it is preferable to heat the film substrate at a heat resistant temperature or lower. here,
The heat-resistant temperature of the film substrate means the upper limit temperature at which the properties of the film substrate can be substantially maintained, and when the film substrate is plastic, the glass transition point, the crystallization temperature or the decomposition point is set. means. From the viewpoint of preventing evaporation of the organosilicon compound (III-1) during drying, it is preferable to use a gas barrier coating agent containing a hydrolytic condensate (III-2) of the organosilicon compound. A known catalyst can be used for this hydrolysis condensation reaction, and it is advantageous to react in a solvent (IV).

As described above, as the organic compound (I) or the organic compound (II), a compound having a SiOR ³ group is used if necessary.
Alternatively, the hydrolysis-condensation product (III) thereof contains a SiOR ² group, but in order for the gas barrier layer to exhibit a sufficient gas barrier property even in a hot and humid environment, these unreacted silanol-based functional groups ( It is preferable that the residual amount of the functional group remaining in the state of SiOR ² or SiOR ³ ) is small. In order to reduce the amount of unreacted silanol-based functional groups remaining, it is preferable to coat the surface of the film substrate with a gas barrier coating agent, cure and dry it, and then perform aging treatment. As the aging treatment, heat treatment (for example, 40 to 60 ° C.)
It is preferable to perform heat treatment for 1 to 7 days) or corona treatment. In addition, after curing and drying, the organic compound (I), which has not reacted with other constituents, should not be present,
It is preferable to set the conditions.

When coating the surface of the film substrate with the gas barrier coating agent, the film substrate may be coated with the gas barrier coating agent of the same composition several times, or may be coated with a different composition. The agent may be coated to make the gas barrier layer a multi-layer structure.

The gas barrier film of the present invention can be widely applied in various fields requiring gas barrier properties, and is not particularly limited.
For example, containers and packaging materials for food and beverages (for example, food packaging films and PET bottle containers on which a gas barrier layer is formed), electronic components used in liquid crystal display devices, mobile terminals or mobile devices (for example, The present invention can be applied to a wide range of applications such as a polymer film substrate having a gas barrier layer of a liquid crystal display), medical equipment and medical instruments (for example, blood storage bags).

[0082]

EXAMPLES The effects of the present invention will be demonstrated using the following examples. However, the present invention is not limited to the following embodiments. The viscosity of the coating agent for gas barrier, the thickness of gas barrier layer, and the oxygen permeability of the gas barrier film were measured by the following methods.

<Viscosity measurement of coating agent for gas barrier> It was measured at 20 ° C. using a viscometer (manufactured by Yamaichi Denki Co., Ltd .: model VM-100A).

<Measurement of Thickness of Gas Barrier Layer> Transmission electron microscope (TEM; JEM-2000F manufactured by JEOL Ltd.)
X) was used to observe the cross section of the gas barrier film.
As the measurement site, the central portion in the width direction of the film was measured every 100 m.

<Oxygen Permeability Measuring Method> The gas barrier film was cut, and the oxygen permeability was measured using an oxygen permeability measuring device (Modern Control Co., Ltd .; model MH). The measurement temperature and the measurement humidity were 20 ° C. and 90% Rh, respectively. The measurement was performed 3 times, and the average value was calculated.

<Example 1> Polyethyleneimine (12k
g: Epomine SP-018 manufactured by Nippon Shokubai Co., Ltd .; organic compound (I)), γ-glycidoxypropyltrimethoxysilane (5 kg; organic compound (II)) and methanol (100 kg; solvent (IV)) Was reacted at 60 ° C. for 3 hours and then cooled to room temperature. Next, water (1.0k
g; solvent (IV)) and methanol (100 kg; solvent (I
V)), and further a mixture of tetramethoxysilane (25 kg; hydrolysis-condensation product (III)) and methanol (50 kg; solvent (IV)),
A coating agent for gas barrier was obtained by aging at room temperature for 24 hours. The coating agent for gas barrier had a viscosity of 5 cps.

The obtained gas barrier coating agent was added to
PET film (width 28 cm, length 1000 m, thickness 1
2 μm; the thickness after drying is 1 μm on one side of the film substrate)
Was applied with a gravure coater. This one
After drying at 00 ℃ for 10 seconds, aging at 60 ℃ for 48 hours, PE
A gas barrier film having a gas barrier layer formed on the T film was obtained. The thickness of this gas barrier layer was measured according to the above method.

Further, this gas barrier film was subjected to a repeated test 40 times using a gel voflec tester (manufactured by Rigaku Kogyo). The measurement temperature and the measurement humidity were 20 ° C. and 60% Rh, respectively. The oxygen permeability before the repeated test (oxygen permeability A) and the oxygen permeability after the repeated test (oxygen permeability B) were measured according to the above method. Table 1 shows the relationship between the thickness of the gas barrier layer and the oxygen permeability.
Shown in.

Comparative Example 1 The coating agent for gas barrier obtained in Example 1 was stored at 50 ° C. for 100 days.
The viscosity of the gas barrier coating agent changed to 19 cps.

The obtained coating agent for gas barrier was
PET film (width 28 cm, length 1000 m, thickness 1
2 μm; the thickness after drying is 1 μm on one side of the film substrate)
Was applied with a gravure coater. This one
After drying at 00 ℃ for 10 seconds, aging at 60 ℃ for 48 hours, PE
A gas barrier film having a gas barrier layer formed on the T film was obtained. The thickness of this gas barrier layer was measured according to the above method.

Further, this gas barrier film was subjected to repeated tests 40 times using a gel voflec tester (manufactured by Rigaku Kogyo). The measurement temperature and the measurement humidity were 20 ° C. and 60% Rh, respectively. The oxygen permeability before the repeated test (oxygen permeability A) and the oxygen permeability after the repeated test (oxygen permeability B) were measured according to the above method. Table 1 shows the relationship between the thickness of the gas barrier layer and the oxygen permeability.
Shown in.

[0092]

[Table 1]

As shown in Table 1, the gas barrier film of the present invention was excellent in bending resistance even after repeated tests, with no significant deterioration in gas barrier property as observed in Comparative Example 1 being confirmed. Met.

[0094]

The gas barrier film of the present invention has a gas barrier coating agent coated on the surface of the film substrate so that the thickness of the gas barrier layer satisfies predetermined requirements. Is improved. That is, it is possible to suppress the deterioration of the gas barrier property when bent. Therefore, it is very useful as a gas barrier film applicable to various industrial fields.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Chiho Yokoe             5-8 Nishiomitabicho, Suita City, Osaka Prefecture             Within Nippon Shokubai (72) Inventor Hiroko Harada             5-8 Nishiomitabicho, Suita City, Osaka Prefecture             Within Nippon Shokubai F-term (reference) 4F100 AA01B AH02B AH06B AK31B                       AK42A AK53B AK54B AT00A                       BA02 BA07 EJ08B GB15                       GB66 JA20B JD02 JK04                       YY00B

Claims (3)

[Claims] 1. An organic compound (I) having a nitrogen atom bound to active hydrogen in the molecule, and an organic compound having a functional group capable of reacting with the active hydrogen to form a chemical bond with the nitrogen atom in the molecule. (II) and the following formula (1): (In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a functional group which does not react with the active hydrogen, and R ² is a hydrogen atom or a C 1 to 4 carbon atom. It is an alkyl group, m is an integer of 0 or more, n is an integer of 1 or more, m + n = 4, and when m or n is 2 or more, R ¹ or R ² may be different. ) Is a gas barrier film obtained by coating and curing a gas barrier coating agent containing an organosilicon compound and / or its hydrolytic condensate (III) and a solvent (IV) on the surface of a film substrate. A gas barrier film having a gas barrier layer thickness measured at 5 points every 100 m in the longitudinal direction of the gas barrier film is within ± 20% of the average value of the gas barrier layer thickness. 2. The average value of the gas barrier layer thickness is 0.
It is 3-2.0 micrometers, The gas barrier film of Claim 1 characterized by the above-mentioned. 3. An organic compound (I) having a nitrogen atom bound to active hydrogen in the molecule, and an organic compound having a functional group capable of reacting with the active hydrogen to form a chemical bond with the nitrogen atom in the molecule. (II) and the following formula (1): (In the formula, R ¹ is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms which may have a functional group which does not react with the active hydrogen, and R ² is a hydrogen atom or 1 to 4 carbon atoms.
Is an alkyl group, m is an integer of 0 or more, and n is 1
It is an integer greater than or equal to m + n = 4, and m or n is 2
In the above cases, R ¹ or R ² may be different) and contains an organosilicon compound represented by the formula (3) and / or its hydrolytic condensate (III) and a solvent (IV), and has a viscosity of 1 to 10
A method for producing a gas barrier film by coating and curing a coating agent for gas barrier of cps (20 ° C.) on the surface of a film substrate.