JP2002206031A - Gas barrier film and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a gas barrier film capable of dealing with the environmental problem, containing no acrylonitrile, no vinyl chloride and no vinylidene chloride, exhibiting greatly excellent gas barrier properties, consequently applicable to various kinds of packaging materials such as food packaging material, medical supply packaging material, etc., a degradation prevention material for construction structure, etc. SOLUTION: This gas barrier film is characterized in that the gas barrier film is obtained by laminating a gas barrier layer formed from a gas barrier coating film-forming resin composition containing a specific resin (A) and a specified resin (B) and a moisture-proof layer formed from a resin (C) having moisture resistance to at least one side of a thermoplastic film and all monomers constituting the resin (A) and the resin (B) contain no acrylonitrile, no vinyl chloride and no vinylidene chloride.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a gas-barrier film-forming resin composition and a gas-barrier film coated with a moisture-proof resin. The present invention relates to a gas-barrier film-forming resin composition and a method for producing a gas-barrier film coated with a moisture-proof resin. The gas barrier film obtained according to the present invention addresses environmental issues.

[0002]

[Prior art] [Technical background] In recent years, diversification of food culture
Due to the sophistication and diversification of medicines, the need to protect the contents of foods and medicines from deterioration and decay for a long period of time has been increasing year by year. Therefore, a high gas barrier property has been required year by year for a plastic film used for a packaging material.

[0003] Conventionally, when a gas barrier property is imparted to a plastic film such as polyethylene, polypropylene, polyethylene terephthalate, polynylon, cellophane or paper, or the like, a gas barrier resin layer is formed on the film. Have been. As a typical example, a gas barrier coating film is formed by applying polyvinylidene chloride (hereinafter referred to as PVDC) on a biaxially stretched film made of a polypropylene film or the like, followed by drying by heating. ing.

JP-A-3-50211 (applicant; Mitsubishi Yuka Birdish Co., Ltd.) discloses a technique for producing an aqueous dispersion of a vinylidene chloride polymer having excellent gas barrier properties and printability. I have. According to this technique, as a monomer mixture (1), 85 to 95% by weight of vinylidene chloride, and one or a mixture of one or more monomers selected from methyl methacrylate, methyl acrylate, and acrylonitrile. After polymerization, 20 to 65% by weight of a monomer selected from the group consisting of methyl methacrylate and vinyl aromatic compound, and an alkyl acrylate, an alkyl methacrylate, Monomer 35 selected from the group consisting of esters
To 80% by weight, and a hydroxyl group-containing monomer 0.2 to 5% by weight
Of the monomer mixture (1) 100
This is a technique for producing a vinylidene chloride-based polymer by using 0.5 to 20 parts by weight of a monomer mixture (2) based on parts by weight. However, in recent years, the flow of dechlorination has begun to accelerate in the packaging material industry due to the environmental problem caused by the dioxin problem, and polyacrylonitrile and polyvinyl alcohol (hereinafter, PVA) have been used as substitute coating agents for PVDC. Is starting to be. However, when polyacrylonitrile is used, since acrylonitrile as a monomer has toxicity, it is necessary to remove acrylonitrile monomer which remains without being polymerized with great effort. Further, if the application to be used is in the food field, a gas barrier resin which does not use such highly toxic acrylonitrile monomer as a raw material as much as possible has been desired. Also,
PVA is generally applied as an aqueous solution, but is applied at a low concentration because it tends to have a high viscosity. But,
When applied at a low concentration, there is a problem that a long drying time and a large amount of drying energy are required, and that the productivity is lowered due to poor coating properties due to the inherent viscosity.

[0005] The present inventors have attempted to solve the above problems.
It has already been found that a film coated with a resin composition having a specific composition has gas barrier properties (Japanese Patent Application No. 11-141590). However, the requirements for gas barrier properties are becoming more stringent year by year, and further improvement in gas barrier properties has been desired.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is intended to coat a resin composition having excellent environmental compatibility, excellent workability and gas barrier properties, and a moisture-proof resin. Thereby, an object is to provide a film having excellent gas barrier properties.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems, and have found that vinylidene chloride,
Gas barrier film-forming resin composition comprising a resin (A) having a specific amount of carboxyl group and resin (B) on at least one surface of a thermoplastic resin film without using acrylonitrile or vinyl chloride monomer as a raw material By laminating a layer formed from the product and a layer formed from the resin (C) having moisture resistance, it was found that a film with further improved gas barrier properties was obtained, and the present invention was completed. .

That is, the present invention is based on the matters described below.
Specified. (1) At least one surface of the thermoplastic resin film has a resin
Formation of gas barrier coating containing (A) and resin (B)
Gas barrier layer formed from water-soluble resin composition, has moisture-proof properties
Gas barrier formed by laminating a moisture-proof layer formed of resin (C)
Rear film, and the resin (A) has a carboxyl group
(A-1), a monomer containing a hydroxyl group
(A-2) and total weight of other monomers (a-3)
Based on the amount, a monomer containing a carboxyl group (a
-1) 5 to 100% by weight of a hydroxyl group-containing monomer (a
-2) 0 to 95% by weight and other monomer (a-3) 0
To 95% by weight of a (co) polymer, wherein the resin (B) is
A monomer (b-1) containing a ruboxyl group,
Having the monomer (b-2) and the other monomer (b-
3) containing carboxyl groups based on the total weight of
0 to 4% by weight of a monomer (b-1)
Monomer (b-2) and / or other monomer (b-3)
96 to 100% by weight of a (co) polymer in total;
And all monomers constituting the resin (A) and the resin (B)
Acrylonitrile, vinyl chloride, vinylidene chloride
A gas barrier film characterized by not containing. (2) In the gas-barrier film-forming resin composition
And the carboxyl group-containing monomer (a-1) and / or
(B-1) is an unsaturated carboxylic acid and contains a hydroxyl group
Monomer (a-2) and / or (b-2) is a hydroxyl group
-Containing unsaturated carboxylate or hydroxyl-containing unsaturated
Ether, and other monomers (a-3) and / or
(B-3) is an alkyl acrylate or an alkyl methacrylate
Acrylates, aromatic monomers, amide group-containing monomers,
Poxy group-containing monomer, butadiene, ethylene, vinyl acetate
At least one selected from the group consisting of
The gas barrier film according to (1), which is characterized in that: (3) Moisture-proof layer formed from moisture-proof resin (C)
Has a moisture permeability of 50 at a temperature of 40 ° C. and a relative humidity of 90%.
0 g / m^TwoCharacterized by being less than or equal to day
The gas barrier film according to (1) or (2). (4) The gas barrier film-forming resin composition is a resin
(A) and a mixture of the resin (B),
The gas barrier fill according to any one of (1) to (3).
M (5) The gas barrier film-forming resin composition comprises a resin
(A) and resin (B) chemically bonded and / or adsorbed
In any one of (1) to (3),
The gas barrier film according to the above. (6) The gas barrier film has a temperature of 20 ° C.
At 65% humidity, 20 per oxygen or carbon dioxide
× 10 ^-13cm^Three・ Cm / cm^Two/ S / mmHg or less
It is characterized by expressing sbarrier properties,
The gas barrier fill according to any one of (1) to (5).
M (7) The gas barrier film-forming resin composition
And based on the total weight of the resin (A) and the resin (B),
10 to 95% by weight of resin (A), 90 to 5 of resin (B)
(1) to (6), wherein
A gas barrier film according to any of the above items. (8) The resin (C) is a polyolefin resin or latex
Selected from the group consisting of resin and polyester resin.
Characterized by at least one type, (1) to
The gas barrier film according to any one of (7). (9) A gas bar containing the resin (A) and the resin (B)
The rear film-forming resin composition further contains a crosslinking agent
In any one of (1) to (8),
The gas barrier film according to the above. (10) Gas comprising a gas barrier film-forming resin composition
The barrier layer is formed on at least one side of the thermoplastic resin film.
After forming a film, a resin (C) having a moisture-proof property is applied to form a moisture-proof layer.
Any of (1) to (9), characterized by forming a film
3. The method for producing a gas barrier film according to item 1. (11) The gas burr according to any one of (1) to (9)
On the moisture-proof layer of
Gas barrier properties
Lum.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Gas barrier property] The gas barrier property in the present invention is AS gas barrier property.
It can be measured by the method prescribed in TMD-3985 or JIS K7126, and the numerical value of the gas barrier property of the present invention means the transmission coefficient when measured at a temperature of 20 ° C and a relative humidity of 65%. The oxygen or carbon dioxide permeability coefficient of the resin composition film obtained by the gas barrier property of the present invention is 20 × 10 ⁻¹³ cm ³ · cm / cm ² / s / mmH.
g or less, more preferably 10 × 10 ^-13 cm ³ · cm / c
m ² / s / mmHg or less, more preferably 5 × 10 ^-13
cm ³ · cm / cm ² / s / mmHg or less, most preferably 2 × 10 ⁻¹³ cm ³ · cm / cm ² / s / mmHg or less.

[Moisture Permeability] The moisture permeability in the present invention is determined by JI
It can be measured by the method specified in SZ0208, and the numerical value of the moisture permeability of the present invention is a temperature of 40 ° C. and a relative humidity of 90%.
Means the amount of permeation of water vapor as measured by. The moisture-permeable layer formed from the moisture-proof resin (C) in the present invention has a moisture permeability of 500 g / m ² · day or less, more preferably 400 g / m ² · day or less, and most preferably 300 g / m ² · day or less.
g / m ² · day or less.

[Carboxyl Group-Containing Monomer] In the present invention, a carboxyl group-containing monomer (a-
1) · (b-1) is not particularly limited as long as it contains a carboxyl group. Specific examples of the carboxyl group-containing monomers (a-1) and (b-1) in the present invention include, for example, unsaturated acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, crotonic acid, and fumaric acid. Carboxylic acids are mentioned, among which acrylic acid, methacrylic acid, maleic acid, and itaconic acid are preferable, acrylic acid,
Methacrylic acid is particularly preferred. These monomers can be selected alone or in combination of two or more.

[Hydroxyl-Containing Monomer] In the present invention, the hydroxyl-containing monomers (a-2) and (b-2)
Is not particularly limited as long as it contains a hydroxyl group. The hydroxyl group-containing monomer (a-2) · (b) in the present invention
Specific examples of -2) include, for example, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl acrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl acrylate, 2-hydroxybutyl methacrylate, -Hydroxy vinyl ether, polyethylene glycol monoacrylate, polyethylene glycol monomethacrylate, polypropylene glycol monoacrylate, a hydroxyl group-containing unsaturated carboxylic acid ester such as polypropylene glycol monomethacrylate or a hydroxyl group-containing unsaturated ether, and these monomers are , Alone or in combination of two or more. Among these, those containing 2-hydroxyethyl acrylate and / or 2-hydroxyethyl methacrylate are particularly preferred. This is because it is excellent in water solubility and good polymerization stability can be obtained.

[Other Monomer (a-3)] In the present invention, the other monomer [other copolymerizable monomer other than (a-1) and (a-2)] (a -3) is other than acrylonitrile, vinylidene chloride and vinyl chloride,
There is no particular limitation. Specific examples of the other copolymerizable monomer (a-3) in the present invention include, for example, methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, n-propyl acrylate, n-propyl methacrylate, isopropyl Acrylate, isopropyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate, alkyl acrylate such as 2-ethylhexyl methacrylate, Alkyl methacrylate; aromatic monomers such as styrene, α-methylstyrene, divinylbenzene, etc .; acrylamide, methacrylamide, N-methylacryl Amide group-containing monomers such as amide and N-methyl methacrylamide; epoxy group-containing monomers such as glycidyl acrylate and glycidyl methacrylate; styrene sulfonic acid and salts thereof, 2-acrylamide-2-methylpropane sulfonic acid and the like Sulfonic acid group-containing monomers such as salts; butadiene; ethylene; vinyl acetate, and the like. These monomers can be selected alone or in combination of two or more. Among these, at least one selected from the group consisting of alkyl acrylates, alkyl methacrylates, styrene, vinyl acetate, acrylamide and methacrylamide is preferable, and those containing alkyl acrylate and / or alkyl methacrylate are particularly preferable. This is because good polymerization stability can be obtained.

[Other monomer (b-3)] Other monomers [other copolymerizable monomers other than (b-1) and (b-2)] (b-3) Preferred are methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, isobutyl acrylate, isobutyl methacrylate, t-butyl acrylate, t-butyl methacrylate, 2-ethylhexyl acrylate , 2-ethylhexyl methacrylate and styrene.

[Resin (A)] Resin (A) in the present invention
Is a (co) of a monomer (a-1) containing a carboxyl group, a monomer (a-2) containing a hydroxyl group, and another copolymerizable monomer (a-3). It is a polymer. The amount of the monomer (a-1) is 5 to 100% by weight, preferably 20 to 100% by weight based on the total weight of the monomers (a-1), (a-2) and (a-3). % By weight, more preferably 3%
5 to 100% by weight. The amount of the monomer (a-2) is set to 0 to 95% by weight based on the total weight. The amount of the other monomer (a-3) is 0 to 95% by weight based on the total weight. With such an amount, a sufficient gas barrier property can be obtained. The total amount of the monomers (a-1) and (a-2) is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, and most preferably 90 to 10% by weight based on the total amount.
0% by weight. With such a total amount, a sufficient gas barrier property can be obtained. The hydroxyl-containing monomer (a-2) and other copolymerizable monomers (a-
3) is appropriately selected according to the performance required of the resin, but when water resistance is particularly required, 5 to 80% by weight of the carboxyl group-containing monomer (a-1), The content of the monomer (a-2) is preferably 20 to 95% by weight, and the content of the other copolymerizable monomer (a-3) is preferably 0 to 75% by weight. a-1)
5 to 50% by weight, hydroxyl group-containing monomer (a-2) 50 to 9
5% by weight, other copolymerizable monomers (a-3) 0
More preferably, it is 45% by weight.

[Glass Transition Temperature of Resin (A)] The theoretical glass transition temperature of the resin (A) is not particularly limited, but is generally 0 ° C. to 200 ° C. When the glass transition temperature of the resin (A) is significantly lower than room temperature, for example, below freezing point, there is a problem that the formed film becomes sticky. On the other hand, when the temperature exceeds 200 ° C., in order to prevent film formation failure, It is necessary to remarkably increase the drying temperature during molding, which is a problem.

[Weight-Average Molecular Weight of Resin (A)] The weight-average molecular weight of the resin (A) is not particularly limited, but is generally preferably from 1,000 to 1,000,000. When the molecular weight is less than 1,000, there is a problem that the water resistance of the formed film is reduced. When the molecular weight is more than 1,000,000, the viscosity of the resin increases and there is a problem that handling becomes difficult.
The molecular weight can be measured by GPC (gel permeation chromatography).

[Resin (B)] Resin (B) in the present invention
Is the total weight of the carboxyl group-containing monomer (b-1), the hydroxyl group-containing monomer (b-2), and the other copolymerizable monomer (b-3). As a reference, 0 to 4% by weight of a monomer (b-1) containing a carboxyl group
And a monomer selected from the group consisting of a hydroxyl group-containing monomer (b-2) and another copolymerizable monomer (b-3).
It consists of a copolymer with at least one or more monomers of 96 to 100% by weight. When the amount of the monomer (b-1) exceeds 4% by weight, the viscosity of the resin increases, and handling may be difficult. The amount of the monomer (b-3) is preferably from 70 to 100, based on the total weight of the monomer (b-1), the monomer (b-2) and the monomer (b-3). % By weight, more preferably 85-100% by weight, most preferably 96-100% by weight. By doing so, the resin (B) can be obtained with good production stability, and the workability of the obtained resin composition is improved.

When water resistance is particularly required, 0 to 2% by weight of a monomer (b-1) containing a carboxyl group,
The hydroxyl group-containing monomer (b-2) is preferably 0 to 20% by weight, and the other copolymerizable monomer (b-3) is preferably 78 to 100% by weight, more preferably a carboxyl group-containing monomer. (B-1) 0% by weight, hydroxyl group-containing monomer (b-2) 0 to 10% by weight, and other copolymerizable monomer (b-3) 90 to 100% by weight.

[Glass transition temperature of resin (B)] The theoretical glass transition temperature of the resin (B) is not particularly limited, but is generally -50 ° C to 200 ° C. The glass transition temperature is appropriately selected under the drying conditions when the emulsion composition according to the present invention is used, and under conditions that allow sufficient film formation.

[Weight Average Molecular Weight of Resin (B)] The weight average molecular weight of the resin (B) is not particularly limited, but is generally 10,000 to 10,000,000.

[Carboxyl groups contained in resin (A) and resin (B)] Carboxyl groups contained in resin (A) and resin (B) include metal salts such as potassium and sodium; ammonia, amine The organic bases can neutralize part or all of the organic base. Organic bases are preferred as the neutralizing agent from the viewpoint of improving gas barrier properties and water resistance of the film. The total amount of the carboxyl group-containing monomers (a-1) and (b-1) is
Based on the total weight of the resin (A) and the resin (B),
Preferably from 10 to 95% by weight, more preferably from 20 to 8%.
0% by weight. By doing so, good gas barrier properties can be obtained.

[Gas-barrier film-forming resin composition containing resin (A) and resin (B)] Gas-barrier film-forming resin composition containing resin (A) and resin (B) according to the present invention The substance is a composition in which the resin (A) and the resin (B) are mixed or chemically bonded, and the chemical bond is a covalent bond, an ionic bond, a hydrogen bond, a coordination bond, or the like. Is also included. The ratio of the resin (A) to the resin (B) is 10 to 95% by weight of the resin (A) and 90 to 5% by weight based on the total weight of the resin (A) and the resin (B).
% By weight. 10% by weight of resin (A)
When the amount is less than the above, the gas barrier properties of the formed film may decrease, and when the amount exceeds 95% by weight, the water resistance of the film may decrease. More preferably resin (A)
The content is 30 to 90% by weight and the resin (B) is 70 to 10% by weight. Most preferably, it is 40 to 90% by weight of the resin (A) and 60 to 10% by weight of the resin (B).

Resin (A) and resin (B) in the present invention
Is preferably dissolved or dispersed in a solvent in terms of handling. More preferably, the resin (A) is dissolved in a solvent, and the resin (B) is dispersed in the solvent as resin particles. The resin particles containing the resin (A) and the resin (B) in the same particle are dispersed in water. Are most preferred. In addition, "resin (A)
And the resin particles containing the resin (B) in the same particle are dispersed in water. "The resin (B) is dispersed in water, and the resin (A) is adsorbed or bonded to the surface of the resin (B). It refers to a state, for example, a form of a composite emulsion composed of a hydrophobic core made of an acrylic polymer and a water-soluble shell made of a water-soluble polymer. As mentioned above, P
Although a water-soluble polymer such as VA is effective as a gas barrier material, it has a problem that the viscosity increases when it is made into an aqueous solution. This is considered to be due to entanglement between molecular chains of the water-soluble polymer in water. In contrast, when the form of the composite emulsion is adopted, the water-soluble polymer is adsorbed or bonded to the surface of the hydrophobic resin dispersion, so that the entanglement between the molecular chains of the water-soluble polymer is suppressed, and the viscosity increases. Can be suppressed. Therefore, better workability can be obtained even when the concentration of the water-soluble polymer is increased, as compared with the case where the form of the aqueous solution is adopted. The solvent used is not particularly restricted but includes, for example, water; alcohols such as methanol, ethanol, isopropyl alcohol and butanol; water-soluble organic solvents such as ketones such as methyl ethyl ketone and acetone; glycols and ethers; Water-insoluble solvents such as toluene and xylene can be used alone or in combination of two or more. In particular, a solvent containing water as a main component is preferable from the viewpoint of environmental problems.

[Third Component] In addition to the resin (A) and the resin (B), a known water-soluble resin may be used in combination with the resin (A) and the resin (B) in the gas barrier film-forming resin composition. It is. Known water-soluble resins include, for example, polyalcohol polymers, sugars, amino acids, polyethylene oxides, polyethylene glycols,
Cellulose etc. are mentioned.

[Production method of gas barrier film-forming resin composition containing resin (A) and resin (B)] Formation of gas barrier film containing resin (A) and resin (B) according to the present invention The production method (polymerization method) of the resin (A) and the resin (B) in the conductive resin composition is not particularly limited, but usually polymerization is performed in a solvent due to a problem of control of heat of polymerization. . Generally, radical polymerization is preferred.

[Initiator] Specific examples of the initiator used when performing radical polymerization include, for example, hydrogen peroxide;
Persulfates such as ammonium persulfate, potassium persulfate and sodium persulfate; cumene hydroperoxide, t-
Organic peroxides such as butyl hydroperoxide, benzoyl peroxide, t-butylperoxy-2-ethylhexanoate and t-butylperoxybenzoate; azo compounds such as azobisisobutyronitrile; Redox initiators in combination with metal ions such as ions and reducing agents such as sodium sulfoxylate, formaldehyde, sodium pyrosulfite, sodium bisulfite, L-ascorbic acid, Rongalite and the like. The amount of the initiator used at the time of radical polymerization is generally 0.1 to 20% by weight based on the total weight of the monomers.

[Molecular weight regulator] If necessary, t
Mercaptans such as -dodecylmercaptan and n-dodecylmercaptan; allyl compounds such as allylsulfonic acid, methallylsulfonic acid and soda salts thereof can also be used as molecular weight regulators.

[Surfactant] Further, in order to improve the stability of the resin particles, it is possible to use a surfactant which is usually used in emulsion polymerization, particularly when the solvent is mainly composed of water. It is suitable for. Examples of such a surfactant include an anionic surfactant, a nonionic surfactant, a cationic surfactant, and other reactive surfactants. One or more of these surfactants may be used in combination. Can be.

Nonionic surfactant Specific examples of the nonionic surfactant include, for example, polyoxyethylene lauryl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene oleyl phenyl ether, polyoxyethylene nonyl phenyl ether, Oxyethylene / oxypropylene block copolymer, tert-octylphenoxyethyl polyethoxyethanol, nonylphenoxyethyl polyethoxyethanol, and the like are included.

Specific examples of the anionic surfactant include, for example, sodium dodecylbenzenesulfonate, sodium lauryl sulfate, sodium alkyldiphenyletherdisulfonate, sodium alkylnaphthalenesulfonate, sodium dialkylsulfosuccinate, stearic acid Sodium, potassium oleate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate sodium dialkyl sulfosuccinate, sodium stearate, sodium oleate, tert -Octylphenoxyethoxy polyethoxyethyl sulfate sodium salt, etc. It is.

Cationic surfactant Specific examples of the cationic surfactant include lauryltrimethylammonium chloride, stearyltrimethylammonium chloride and the like.

[Average Particle Diameter of Resin Particles] In the present invention, the average particle diameter of the resin particles constituting the resin composition is as follows:
It is preferably from 1 to 1000 nm, more preferably from 1 to 50 nm.
0 nm. When the particle size exceeds 1000 nm,
There are problems such as a loss of smoothness of the formed film and a decrease in gas barrier properties.

[Polymerization method] At the time of polymerization, the above-mentioned various monomers are mixed with a solvent in a lump or divided.
Alternatively, it is continuously added dropwise and polymerized at a temperature of 0 ° C. to 200 ° C. in the presence of the initiator described above.

The gas-barrier film-forming resin composition of the present invention is obtained by mixing or chemically bonding the resin (A) and the resin (B). The resin (A) and the resin (B) are obtained by the above-described method. ), A method of mixing and stirring the resin (A) and the resin (B); a method of polymerizing the resin (B) in the presence of the resin (A); a method of polymerizing the resin (A) in the presence of the resin (B) A desired resin composition can be obtained by a method of polymerizing the compound. As the polymerization performed at this time, it is possible to use the above-described polymerization method, solvent, initiator, molecular weight modifier, and surfactant.

[Additives] Various additives may be added to the resin composition of the present invention, if necessary. Examples of the various additives include a crosslinking agent, a pigment, a film-forming auxiliary, a wetting agent, an antifoaming agent, a preservative, a thickener, a heat stabilizer, an ultraviolet absorber, a lubricant, a coloring agent, an antistatic agent, and an antistatic agent. Examples include a blocking agent and an inorganic salt. Among them, a wetting agent is preferably used in combination when coating the resin composition on a polyolefin film. Further, since a crosslinking agent and a pigment can improve various performances of a formed film, it is preferable to use them together.

[Crosslinking Agent] The crosslinking agent in the present invention improves the water resistance of the film formed from the resin composition and, in some cases, increases the density of the resin composition film, thereby improving the gas barrier properties under humidity conditions. It plays a role in improving the performance. Specific examples of the crosslinking agent include metals such as iron, zinc, tin, copper, aluminum and zirconium and salts thereof; inorganic acids such as hydrochloric acid and sulfuric acid and salts thereof; organic acids such as phosphoric acid and acetic acid and salts thereof; melamine Isocyanate compound; epoxy compound containing glycidyl group; aldehyde compound such as glyoxal; oxidizing agent such as peroxide; imines such as ethyleneimine; imide group-containing compound; oxazoline group-containing compound; aziridinyl group-containing And the like. Of these compounds,
Particularly preferred as a crosslinking agent are metal salts and salts thereof, methylol compounds, isocyanate compounds, epoxy compounds, aldehyde compounds, and imide group-containing compounds. The addition rate of these crosslinking agents is 0.05 to 2 molar equivalents based on the total molar amount of the carboxyl groups and / or hydroxyl groups of the resin (A) and the resin (B). 0.1 to 1 molar equivalent. In general, the optimum addition amount differs depending on the addition ratio of the crosslinking agent and the type of the crosslinking agent. However, when the addition amount is less than 0.05 molar equivalent, the water resistance effect due to the addition of the crosslinking agent may not be exhibited, and 2 mol If the amount is more than the equivalent, an unreacted crosslinking agent remains in the resin film, so that the gas barrier property may decrease. The crosslinking agent to be used can be used alone or in combination of two or more of the above compounds.

[Pigment] Specific examples of the pigment include kaolinite, halosite, montmorillonite, vercurite, dickite, nacryte, antigolite, pyrophyllite, hectorite, beidellite, margarite, talc, and tetrasilyl. Inorganic layered compounds such as mica, muscovite, phlogopite, chlorite; inorganic compounds such as kaolin, calcium carbonate, titanium oxide, silicon oxide, calcium fluoride, lithium fluoride, alumina, barium sulfate, zirconia, calcium phosphate; Organic fillers such as polystyrene-based particles can be used. The addition ratio of these pigments is generally 1 to 30% by weight based on the total weight of the monomers. Furthermore, 1 to 15% by weight
Is more preferred. When the addition ratio of the pigment exceeds 30% by weight, fine gaps are formed in the formed film, and the gas barrier property may decrease. When the addition ratio is less than 1% by weight, the effect of the addition may not be obtained. is there.

[Moisture Proof Resin (C)] The moisture proof resin (C) of the present invention prevents a decrease in the barrier property due to moisture absorption of the gas barrier layer by forming and coating a film on the gas barrier layer. In addition, it is possible to prevent defects of the gas barrier layer due to scratches and the like, and to play a role of improving gas barrier properties under humidity conditions. Furthermore, by appropriately selecting the resin (C), a heat sealing property can be imparted. Specific examples of the resin (C) include polyolefin resins composed of polyethylene, polypropylene, paraffins, thermoplastic elastomers, ionomers and the like; styrene-butadiene copolymers, alkyl acrylate-butadiene copolymers, alkyl methacrylate-butadiene copolymers. Latex resins such as coalesce; polyester resins composed of phthalic acid-glycol condensate; and the like, which can be used alone or in combination of two or more. Among the above resins, a polyolefin resin is particularly preferred as the moisture-proof resin (C).

Resin (C) having moisture-proof properties in the present invention
Is preferably dissolved or dispersed in a solvent (emulsion or the like) in terms of handling. The solvent used is not particularly restricted but includes, for example, water; alcohols such as methanol, ethanol, isopropyl alcohol and butanol; water-soluble organic solvents such as ketones such as methyl ethyl ketone and acetone; glycols and ethers;
Water-insoluble solvents such as toluene and xylene can be used alone or in combination of two or more.
In particular, a solvent containing water as a main component is preferable from the viewpoint of environmental problems.

[Other components] Further, in the resin (C),
As other components, known water-soluble resins can be used in combination. Known water-soluble resins include
For example, polyalcohol polymers, sugars, amino acids, polyethylene oxides, polyethylene glycols, celluloses and the like can be mentioned.

[Thermoplastic resin film] Specific examples of the thermoplastic resin film include polyolefins such as polyethylene and polypropylene; polyethylene terephthalate;
Polybutylene terephthalate, polyethylene-2,6-
Polyesters such as naphthalate; polyamides such as nylon 6 and nylon 12; ethylene-vinyl acetate copolymer or saponified product thereof; polystyrene; polycarbonate; polysulfone; polyphenylene oxide; polyphenylene sulfide; aromatic polyamide; polyimide; polyamideimide; A polyvinyl alcohol, and a copolymer thereof. From the viewpoints of cost performance, transparency, gas barrier properties, and the like, films of polyolefin, polyester, polyamide, and the like are preferable.

[Gas Barrier Film] The gas barrier film according to the present invention means a gas barrier layer formed from a gas barrier film-forming resin composition on at least one surface of a thermoplastic resin film, and a resin (C) having moisture resistance. It is a gas barrier film in which a moisture-proof layer formed from is laminated. When the film has a multilayer structure, the gas barrier layer and the moisture-proof layer in the present invention may be used in any of the upper layer, the lower layer, and the intermediate layer. As an example of the multilayer structure, for example, it is possible to take a form of a multilayer film in which a layer made of a thermoplastic resin film is further laminated on a moisture-proof layer. By adopting such a structure, it is possible to effectively prevent the film layer made of the resin composition for forming a gas barrier film of the present invention from being damaged or absorbing water, thereby deteriorating the film properties. The thickness of the gas barrier layer and the thickness of the moisture-proof layer are appropriately set.
The thickness (thickness after film formation and drying) can be 1 to 20 μm, preferably about 0.5 to 10 μm. As a film forming method, any generally known method can be used without any particular problem. For example, a resin composition can be uniformly applied to one surface of a thermoplastic resin film using a bar coater, a roll coater, or the like, and then the solvent can be evaporated using a hot-air drier or the like to form a resin film.

[0044]

Next, the present invention will be described more specifically with reference to examples. Hereinafter, all parts and percentages are based on weight.

Example 1 746 parts of deionized water was charged into a reaction vessel and heated to 80 ° C. under a nitrogen stream. Separately, 2-hydroxyethyl methacrylate 290
And a mixture of 194 parts of acrylic acid were neutralized with 108 parts of a 20% aqueous sodium hydroxide solution, and 49 parts of potassium persulfate was added and dissolved in a reaction vessel as an initiator. The mixture was dropped into the reaction vessel in 2 hours,
Thereafter, the temperature was further maintained at the same temperature for 2 hours to complete the polymerization.
Thereafter, 590 parts of ion-exchanged water is added to the reaction vessel, and 80
The temperature was raised to ° C. Separately, 57 parts of n-butyl acrylate, 2 parts of 2-hydroxyethyl methacrylate,
A mixed solution of 1 part of methacrylic acid was prepared, and 0.3 part of ammonium persulfate was added and dissolved as an initiator in the reaction vessel. After that, the monomer mixture was dropped into the reaction vessel in 3 hours. The mixture was maintained at the same temperature for 1 hour, 0.1 part of ammonium persulfate was added as a catalyst, and further maintained at the same temperature for 2 hours to complete the polymerization. The solid content of the obtained resin is 30%, pH
Is 4.8, and the weight average particle diameter by light scattering measurement is 0.3.
μm. Cymel C350 (a product of Mitsui Cytec Co., Ltd.) was added to the obtained resin as a melamine-based crosslinking agent at 165.
Was added and stirred and mixed well to obtain a gas-barrier film-forming resin composition. The obtained resin was applied on a 23 μm-thick polyethylene terephthalate film (hereinafter referred to as PET) so as to have a thickness of 2.0 μm after drying, and immediately dried with a hot air drier at 100 ° C. for 1 minute to remove water. After evaporating, further heating for 3 minutes in a hot air drier at 150 ° C., and as a moisture-proof resin, Chemipearl S659 (polyolefin emulsion, manufactured by Mitsui Chemicals, Inc., moisture permeability 30)
0 g / m ² · day) was applied so that the film thickness after drying became 3.0 μm, and immediately dried with a hot air dryer at 150 ° C. for 1 minute to prepare an evaluation film. The oxygen gas permeability was measured under the condition of 65%. afterwards,
The oxygen gas permeability and the oxygen gas permeability coefficient of the resin film alone were calculated by the following formulas. The results are shown in Table 1. 1 / P <total> = 1 / P <film> + 1 / P <
PET> P <total>: Oxygen gas permeability of a laminated film obtained by laminating a PET film and a resin composition film P <film>: Oxygen gas permeability of a resin composition single film P <PET>: Polyethylene terephthalate film (PET) Oxygen gas permeability of a single substance Gas permeability coefficient = 1.523 × 10 ⁻¹² × P <film>
Xdd: thickness (mm) of the resin composition unit film [Example 2] The resin having moisture-proof property of Example 1 was prepared using Chemipearl S75N (polyolefin emulsion, manufactured by Mitsui Chemicals, Inc., moisture permeability 300 g / m ^2).・ Day)
An evaluation film was prepared in the same manner as in Example 1 except that the drying temperature after application of Chemipearl was changed to 100 ° C.
The oxygen gas permeability was measured, and the oxygen gas permeability coefficient was calculated. The results are shown in Table 1.

Comparative Example 1 An evaluation film was prepared in the same manner as in Example 1 without applying a moisture-proof resin, the oxygen gas permeability was measured, and the oxygen gas permeability coefficient was calculated. . The results are shown in Table 1.

[0047]

[Table 1]

[0048]

The gas barrier film according to the present invention comprises:
Responds to environmental issues and does not contain acrylonitrile, vinyl chloride, or vinylidene chloride, and exhibits extremely excellent gas barrier properties. Therefore, it can be applied to various packaging materials such as food packaging materials and pharmaceutical packaging materials, and materials for preventing deterioration of building structures.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI Theme coat ゛ (Reference) C08L 33/04 C08L 33/04 F term (Reference) 4F006 AA35 AB05 AB13 AB24 AB35 BA05 BA10 CA00 CA07 DA04 4F100 AK01A AK01B AK01C AK01D AK03C AK04B AK04J AK11B AK11J AK22B AK22J AK24B AK25B AK25J AK29B AK29J AK41C AK42 AK46B AK46J AK53B AK53J AL01B AL05B BA03 BA04 BA07 BA10A BA10C BA10D CA02B EG002 EH462 GB15 JB16A JB16D JD02B JD03 JD04C JL00 JM01C 4J002 BG01W BG07X DA076 DA086 DA096 DA106 DA116 DD016 DG036 DH026 EE016 EF036 EK006 EL026 EN006 ER006 EU016 EU026 EU186 EU226 FD146 GH02

Claims (11)

[Claims] 1. A gas barrier layer formed from a gas-barrier film-forming resin composition containing a resin (A) and a resin (B) on at least one surface of a thermoplastic resin film, and a resin (C) having a moisture-proof property. A gas barrier film obtained by laminating a moisture-proof layer to be formed, wherein the resin (A) is a monomer (a-1) containing a carboxyl group, a monomer (a-2) containing a hydroxyl group, and Other monomers (a-3)
Based on the total weight of the monomer (a-1) having a carboxyl group of 5 to 100
% By weight, a (co) polymer of 0 to 95% by weight of a monomer (a-2) containing a hydroxyl group and 0 to 95% by weight of another monomer (a-3), wherein the resin (B) is A monomer containing a carboxyl group (b-1), a monomer containing a hydroxyl group (b-2),
And 0 to 4% by weight of a monomer (b-1) containing a carboxyl group and a monomer (b-2) containing a hydroxyl group, based on the total weight of the other monomers (b-3) And / or 96 to 100% by weight of the total of the other monomers (b-3) as a (co) polymer, and is included in all the monomers constituting the resin (A) and the resin (B). A gas barrier film, which does not contain acrylonitrile, vinyl chloride, and vinylidene chloride. 2. In the gas-barrier film-forming resin composition, a carboxyl group-containing monomer (a-1) and / or
Or (b-1) is an unsaturated carboxylic acid, and the hydroxyl group-containing monomer (a-2) and / or (b-2) is a hydroxyl group-containing unsaturated carboxylic acid ester or a hydroxyl group-containing unsaturated ether. And the other monomer (a-3) and / or
Or (b-3) is at least selected from the group consisting of alkyl acrylates, alkyl methacrylates, aromatic monomers, amide group-containing monomers, epoxy group-containing monomers, butadiene, ethylene, and vinyl acetate The gas barrier film according to claim 1, wherein the film is a kind. 3. The moisture-proof layer formed of the moisture-proof resin (C) has a moisture permeability of 500 g / m ² · day or less at a temperature of 40 ° C. and a relative humidity of 90%. Or the gas barrier film according to 2. 4. The gas barrier film according to claim 1, wherein the gas barrier film-forming resin composition is a mixture of a resin (A) and a resin (B). 5. The gas-barrier film-forming resin composition according to claim 1, wherein the resin (A) and the resin (B) are chemically bonded and / or adsorbed. The gas barrier film according to 1. 6. The gas barrier film having a temperature of 20.
At 65 ° C and 65% relative humidity.
Come, 20 × 10 ^-13cm^Three・ Cm / cm^Two/ S / mmHg
It is characterized by exhibiting the following gas barrier properties
The gas barrier film according to any one of claims 1 to 5,
Film. 7. The resin composition for forming a gas-barrier film has a resin (A) content of 10 to 95% by weight and a resin (B) content of 90 based on the total weight of the resin (A) and the resin (B).
The gas barrier film according to any one of claims 1 to 6, wherein the content is 5 to 5% by weight. 8. The gas barrier property according to claim 1, wherein the resin (C) is at least one selected from the group consisting of a polyolefin resin, a latex resin, and a polyester resin. the film. 9. The gas barrier film-forming resin composition comprising the resin (A) and the resin (B), further comprising a crosslinking agent. Gas barrier film. 10. A gas barrier layer comprising a gas-barrier film-forming resin composition is formed on at least one surface of a thermoplastic resin film, and then a moisture-proof resin (C) is applied to form a moisture-proof layer. The method for producing a gas barrier film according to any one of claims 1 to 9, wherein: 11. A gas barrier film, wherein a thermoplastic resin film is further laminated on the moisture-proof layer of the gas barrier film according to any one of claims 1 to 9.